uSupply Custom LCD

[EEVblog]

Custom LCD proposal for the new µSupply
Comments foolishly invited

[nidlaX]

Will the entire unit be produced by an OEM? Why not use a character or graphic LCD?

[ataradov]

I'd replace ON/OFF with something easier to read at a glance. Something like an outer circle with an inner filled circle. Not sure if this exact combination is possible with LCD technology.

Or dual back light color for ON/OFF states.

[nidlaX]

Or dual back light color for ON/OFF states.

Maybe have a multicolor LED backlight for the output button? I like the LCD  backlight idea, but someone might want to leave the LCD backlight disabled while in use.

[mariush]

Looks ugly to me.

Might as well spring for a graphic LCD ...  128 x 64 pix lcd screens are not so expensive.

Might not be as big, but would look better.   CV and CC and on/off could be made with some basic red leds, by the side of the actual graphical lcd

example: https://www.digikey.com/product-detail/en/newhaven-display-intl/NHD-12864AZ-NSW-BBW-TR/NHD-12864AZ-NSW-BBW-TR-ND/1701279

[ataradov]

Might as well spring for a graphic LCD ...  128 x 64 pix lcd screens are not so expensive.

Try to actually fit all this information on 128x64 LCD. It is not easy to do and have a good readability.

But I do agree, CC, CV, ON/OFF are better on dedicated LEDs. This is information that has to be readable from any angles and fast.

[mariush]

The set voltage and current (limit, whatever) and maybe the watts or some battery gauge could be in a smaller font where that white bar is in my previous post in the picture.  Maybe a 5x7 font or something, let's say 12 vertical pixels. That would still leave 52 vertical pixels to put the current voltage and current .. let's say 20-22 px tall digits, leaving 8-10 pixels for borders and crap.

For watts, either show it on the top bar, or maybe have a button that when pressed, you'll see the watts on screen... 

Or you could have a "white bar" at top and one at bottom and two numbers centered in the middle of the screen.

[EEVblog]

Only 20 times the price.

[ataradov]

Only 20 times the price.

It also looks like the image is "approximation of reality", or whatever they like to put on boxes of things with displays. There is no way it look this solid in real life.

PS: I'd like to hear about your experience ordering custom LCDs.

[VEGETA]

It looks so bad, I prefer a TFT even with increased price.

What happened to the project anyway? I thought the circuit with LT3080 used to oscillate.

[ataradov]

It looks so bad, I prefer a TFT even with increased price.

This looks strange because of color scheme used here and all segments being on.

It will look fine in real life. And I personally prefer segment displays, since they are easier to read.

[ebclr]

A bar graph on the button will be something very useful, I would set one

Also, I would add an independent H letter just after W , hot help on indicating watt-hour

ON top of the W will be nice to have a  mAH also to set milliampere hour accumulated, ( quite useful for battery relative works )

[Howardlong]

PS: I'd like to hear about your experience ordering custom LCDs.

Me too!

[Whales]

Indicator LEDs for important modal information would be brilliant.  If you don't want the case/assembly hassle, then it would be nice to display the modes using large, inverted patches.



Slightly fuzzy examples attached.  Overall this is a bit too crowded, reducing the font size slightly so there are gaps between the rows would make things easier.

[Whales]

Here we go.  Adding a little bit more vertical space between the three "row sections" makes it much easier to find your visual bearings when you glance at the display.

[mikeselectricstuff]

Horizontal bargraph for current would be good.

You should also put the EEVBLOG hand logo on there, because you can.

I'd be really interested in finding out about the process of getting a custom display made - tooling costs, unit costs,MOQ, leadtime, design rules etc.

[Whales]

I'd recommend you make some 1:1 printouts and stick them to the front of test equipment you use all the time.  Things like the decimal points being hard to see become more obvious in context.

[VEGETA]

But what about the project itself? last time I checked it I read people say the circuit won't work and will oscillate. Is there a new version or something?

[EEVblog]

I'd be really interested in finding out about the process of getting a custom display made - tooling costs, unit costs,MOQ, leadtime, design rules etc.

That's the plan.

[julianhigginson]

Whales, That design looks great!

[Mr. Scram]

I think a bit more space between the lines would increase readability. I like the design outlined by Whales. The filled areas add quite a bit of pzaz. Mike's bar suggestion is a good one too.

It looks so bad, I prefer a TFT even with increased price.

What happened to the project anyway? I thought the circuit with LT3080 used to oscillate.

Not to mention the durability of "simple" LCD displays. They take years to fade or break.

[jpc]

Whale's design with the greater spacing between character lines makes it far more readable. The original seems cluttered and confused while adding the wider spacing even at the expense of some character size makes a real positive difference to readability.

[mikeselectricstuff]

I'd be really interested in finding out about the process of getting a custom display made - tooling costs, unit costs,MOQ, leadtime, design rules etc.

That's the plan.

Are you going the "safe" route of talking to local distributors etc. or taking a chance & chucking some drawings cash at someone  from Alibaba & crossing fingers...?
I've been sort-of tempted to try the latter just for the hell of it.  The prices and leadtimes are so different from anything I've been told when talking to UK distributors.
I spoke to someone yesterday at EDS  who was talking 12-16 weeks, though I suspect that some of the Alibaba places quoting "3-4 days for samples" have a slightly different idea of the meaning of "custom", but there are some that list some more plausible leattimes of 2-3 weeks.
I really can't imagine that any Chinese place could survive with 3-4 month leadtimes. 

[Mr. Scram]

Whale's design with the greater spacing between character lines makes it far more readable. The original seems cluttered and confused while adding the wider spacing even at the expense of some character size makes a real positive difference to readability.

Character size isn't everything for legibility. User experience is as much an art as it is a science, and it is often very undervalued. I think John Kenny rightfully emphasized the effort that often goes into it and how important it is for the success of the device. Of course, if it's done right, you will actually never notice it.

Maybe it pays to get a professional with experience to look at the matter. There tend to be lots of knacks, tricks and pitfalls that take experience to know and take into account. Although I think Whales' version is a great improvement already.

[NivagSwerdna]

What sort of minimum order quantity is there for a custom LCD? 10, 100, 1000, 10000, 100000000000000000000?

[Mr. Scram]

What sort of minimum order quantity is there for a custom LCD? 10, 100, 1000, 10000, 100000000000000000000?

I gather that fully depends on the bag of money you bring. If you want one, they'll make one. Just beprepared to bring a large bag.

[tszaboo]

Slightly fuzzy examples attached.

I would prefer this one. Maybe CC should be an LED but that's just me.
Also is OCP planned? Because you need something for that for the LCD. Blinking maybee...

[xani]

I'd prefer graphical LCD ( or hell, even text one at cost of readability) just because it would make it easier to hack the firmware and add extra features like "work as battery charger" or "work as phone charger"

[NivagSwerdna]

What sort of minimum order quantity is there for a custom LCD? 10, 100, 1000, 10000, 100000000000000000000?

I gather that fully depends on the bag of money you bring. If you want one, they'll make one. Just beprepared to bring a large bag.

So they make 100000000000000000000, bin 99999999999999999999 and dispatch 1? 

I googled and found a site suggesting tooling cost is around $2-3k

[Mr. Scram]

So they make 100000000000000000000, bin 99999999999999999999 and dispatch 1? 

I googled and found a site suggesting tooling cost is around $2-3k

I think they make a handful and ship one. There is no obligation to do a full run, you just need enough to tweak to process to something acceptable and ship one of the succesful ones.

[dr.diesel]

What are the approx dimensions? 

[mariush]

Just for fun, you could just order thousands of those 0603 leds and make your own seven segment digits at the size you want.

Then just use some of that brown/black foil (display film) that improves contrast and spreads the led light more uniformly and maybe laser cut the segments from a transparent plastic foil you can stick to this display film.

Probably costs more in leds and pick and place and all that, but no MOQ, no tooling costs, you can iterate through several layouts faster etc etc 

[ebclr]

LCD main reason is cost, if cost is not an issue a TFT will fit much better than a lot of Leds, one LCD like that will cost less than 1USD, in 1K units, plus 300Usd for tooling

[jpc]

I quite agree, for over the years I've seen many a piece of otherwise excellent kit made virtually unusable by a poorly thought out display, assuming there was any thought put into the design beyond cramming on as much display information as possible. Sometimes less is more, as Whale's improvement over the  original, while relatively minor in of itself, leads to a significantly more readable display,at least IMO. 


Unfortunately, over the years, I found that for all their other good qualities, engineers were often the last people you wanted in charge of designing displays and UIs. For unless they had some training in display/UI design, the tendency was to cram every piece of information they could onto the display. Something I have been guilty of myself in my early years in engineering before I was lucky enough to work for some multi-disciplinary teams that included members who maybe had little or limited engineering experience, initially anyway, but did understand what worked in displays and UIs with many often coming from a graphic arts or design background.

[KNSSoftware]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

[kalel]

I quite agree, for over the years I've seen many a piece of otherwise excellent kit made virtually unusable by a poorly thought out display, assuming there was any thought put into the design beyond cramming on as much display information as possible. Sometimes less is more, as Whale's improvement over the  original, while relatively minor in of itself, leads to a significantly more readable display,at least IMO. 


Unfortunately, over the years, I found that for all their other good qualities, engineers were often the last people you wanted in charge of designing displays and UIs. For unless they had some training in display/UI design, the tendency was to cram every piece of information they could onto the display. Something I have been guilty of myself in my early years in engineering before I was lucky enough to work for some multi-disciplinary teams that included members who maybe had little or limited engineering experience, initially anyway, but did understand what worked in displays and UIs with many often coming from a graphic arts or design background.

I could be wrong with this as I have no such design experience at all (anything related to hardware), but when possible/practical, it might help to have a simulated emulated working model first. If it's a display, perhaps model it on the PC, make a little emulation app for the GUI (just the GUI and some controls - obviously not a simulation of the entire real usage) and try to use it and/or ask others in the team to do the same. This is just to get a sense on whether or not it is intuitive.

[mikeselectricstuff]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

And the problem with that is..?
I'm sure Dave will (if only out of necessity/MOQ) have plenty of displays available
The cost of buying parts (whether from Dave or making your own batch) has no bearing on the open-sourceness or otherwise.
 

[jpc]

kalel, ideally you want 'outsiders' to look it over as well as users with a range of experience and for them to use it for a while as the design team are often too close. Of course, how far down the external testing route you can go will depend on the budget but scrimping on the display/UI is often a false economy. It can mean the difference between a great device and something you reluctantly dig out of the bottom of the cupboard because its the only device you have that can do that particular task.

[tszaboo]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

In that case, the Arduino Uno wouldn't be open source, because you gotta use an ATMega328 on it, and it is only manufactured by Microchip (so strange to even write this).

[free_electron]

Here we go.  Adding a little bit more vertical space between the three "row sections" makes it much easier to find your visual bearings when you glance at the display.

this on has my vote. however, i would like to see 3 small indicators ( a number 1 ,2 and 3 with a circle around them , showing that a preset is in effect )

[jpc]

Quote from: KNSSoftware on Today at 16:00:35

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

Open Source just refers to the licensing applying to the design and says nothing about the availability of components.

[mariush]

In that case, the Arduino Uno wouldn't be open source, because you gotta use an ATMega328 on it, and it is only manufactured by Microchip (so strange to even write this).

But you can buy the part from multiple sources, while you would only be able to buy the part from Dave and he could impose artificial restrictions like 1 part per household to make sure you're not making custom versions to sell them.
In contrast, I can buy the Atmega328 from lots of places.

With such parts like made-to-order display, you'd force someone to also spend money and order a compatible display in volume and pay tooling costs. Not cool.. not illegal, not against open source and all that, just not cool.
 

[ataradov]

With such parts like made-to-order display, you'd force someone to also spend money and order a compatible display in volume and pay tooling costs. Not cool.. not illegal, not against open source and all that, just not cool.

Or Dave can just close source the whole thing and not have to deal with open-source whiners.

Custom display is a cool feature, and I'm looking forward for the practical description on how to order one. To use in my open projects.

[mariush]

Custom display is a cool feature, and I'm looking forward for the practical description on how to order one. To use in my open projects.

That's easy. Go at companies like Digikey, Mouser, Newark/Farnell and make a list of companies that sell lcd displays, then go on alibaba / aliexpress and make a list of companies that sell lcd displays in volume
then find email addresses or phones for every one of them and send emails / call and ask about custom lcd displays and how much would cost, minimum order quantity and all that.

It's not rocket science, it just takes a lot of time and research.

Whatever Dave picks may not be the best for you anyway, he'll most likely pick something that's convenient for him and his location (Australia) , just like he does his circuit boards in New Zealand or somewhere close to him.

[ataradov]

It's not rocket science, it just takes a lot of time and research.

Exactly. And I'm looking for someone to do this research.

Anyway, this is OT here.

[texaspyro]

I don't like the idea of a custom display.   Just look at all the test equipment repair threads where a failed, unobtainium display is problem.   Particularly painful is all the devices that used VFD displays with a known finite lifetime and wearout mechanism.

I have a front panel replacement design on the back burner for my HP-531xx counter for when the VFD eventually fails.  The only way to replace the VFD now is to send HP $1800 for a new front panel board.

[mikeselectricstuff]

Overcurrent indication...

[mikeselectricstuff]

If you have any spare segment lines, adding the additional decimal points (especially on the watts) wouldn't hurt, for future expansion or use on other things, like a dummy load perhaps, or for indicating mains voltages ( e.g. a volatge/power logger). maybe add a Hz icon?

[KNSSoftware]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

In that case, the Arduino Uno wouldn't be open source, because you gotta use an ATMega328 on it, and it is only manufactured by Microchip (so strange to even write this).

no the ATMega is not custom and solely distributed by arduino, it is an off the shelf produt like any of the product components on the board.  This would be custom and only available via Dave, it is not the same.

[TimNJ]

Going off some other's ideas...here's what I came up with. It's a different aspect ratio, but perhaps that's okay (since it's custom)?

I don't see a benefit to using italics. I think it's just harder to read for no reason. I think it would be nice to have the 'Set' and 'Measured' voltages/currents clearly defined. It's a power supply; The learning curve should be <10 seconds, in my opinion.

Also, if you use an RGB LED backlight, the screen could be, say, yellow in the 'output-off' state, green in 'CV' and red in 'CC'.

Let me know what you guys think!

[KNSSoftware]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

And the problem with that is..?
I'm sure Dave will (if only out of necessity/MOQ) have plenty of displays available
The cost of buying parts (whether from Dave or making your own batch) has no bearing on the open-sourceness or otherwise.
 

I agree 'cost' has no baring, that is not my 'issue'.  My 'issue' (a term grossly exaggerated, as I will not personally be affected, but do feel is worth mentioning), is that the part relies on purchasing a part only available via the designer of the 'open source' project.  Obviously other parts are also proprietary, but they are not affiliated with he designer. i.e you can only follow the free design by Dave, by purchasing the display from Dave.  It does seem a bit borderline to me.

[floobydust]

LCD character displays used to be expensive for lithography, glass - high NRE, high min. order quantities and long lead times. For a basic display like this, I don't see it worth it.
You'd always have a box of 10,000 displays lying around.

Had a product with similar custom LCD display from GPEG in UK and very low cost, no big MOQ, and their own graphic design software. Hit'em up and see. It was refreshing to not have to spend big bucks.


OP's LCD display has no innovation, it's just some numbers.
A power supply from 40 years ago has the same numbers, just on an analog panel meter. Yawn.

This small OLED meter I buy for $7 and put on my bench power supplies. Popular meter in china.
It has extra measurements I find useful, such as Ahr, run time, temperature from a STM32.

I do not know the project here but wonder if it's to be low cost or what the goal is.

[glarsson]

Example of a terrible UI.

[floobydust]

What's terrible about it?
One button, press and hold to reset integrators. Press again to do calibration.

[mikeselectricstuff]

Had a product with similar custom LCD display from GPEG in UK and very low cost, no big MOQ, and their own graphic design software. Hit'em up and see. It was refreshing to not have to spend big bucks.

Do you have any figures?

[glarsson]

What's terrible about it?

Too much information in a small area.
Placement of Ah and Wh has logical relation to placement of A, W and T. Just random.
Irrelevant information (temperature).
Seriously ugly font.
Typical UI designed by a software engineer.

[Howardlong]

A number of the responses on this thread remind me of why I rarely open source revenue earning projects.

o You end up having your entire project designed and redesigned by an unappointed committee of big mouths of indeterminant provenance.

o People who profess to have no interest can’t help being self-appointed project managers.

o You waste valuable time second guessing your own judgement on every minutiae of your project.

o You lose focus during the design and manufacturing cycle going off on unnecessary tangents.

o Of course, a good dose of opinionated time wasting of what is - and is not - open source is unlikely to get a product to market any quicker, quite the opposite in fact.

This is all hugely unproductive and time wasting.

Remember, you can please some of the people some of the time, but you can’t please all of the people all of the time.

If you don’t like the way someone else’s project is going, and are not a stakeholder, but you feel the need to try to make a fundamental design change from afar to fulfill your own utopian agenda, then you should reconsider and instead invest your effort more productively on your own designs.

Be careful what you wish for, because these kinds of distractions take away from the open source community, and they certainly don’t encourage it or show it in a good light.

[ataradov]

Apart from open-source ramblings, I feel like the proposed design change is for the better. Whether Dave ends up using any of this is up to him, of course, but I'd say this thread was productive.

[Howardlong]

Apart from open-source ramblings, I feel like the proposed design change is for the better. Whether Dave ends up using any of this is up to him, of course, but I'd say this thread was productive.

I agree with the concept around redesigning the display layout, after all that is the point of the OP, it’s all the other nonsense about whether or not it constitutes open source, that adds no value, it’s divisive and a net complete waste of everyone’s time.

[KNSSoftware]

Apart from open-source ramblings, I feel like the proposed design change is for the better. Whether Dave ends up using any of this is up to him, of course, but I'd say this thread was productive.

I agree with the concept around redesigning the display layout, after all that is the point of the OP, it’s all the other nonsense about whether or not it constitutes open source, that adds no value, it’s divisive and a net complete waste of everyone’s time.

Why is it nonsense.? I have one opinion, and you don't share it.  Fair enough, but it doesn't make it nonsense.  In terms of your complete waste of time, no one asked you to express your disagreement.  It took you a couple seconds to read, and you decided to waste your own time to comment your disapproval.   You don't have to go on record, if you don't agree with everything.

Just for the record, I want to see Dave do it.  I and many others will learn loads.  But I don't think it invalidates my opinion.

[TimNJ]

Here's what my rendition would look like in CC mode (backlight turns red). Also changed the heading. Just some ideas! (Can't help myself.)

[glarsson]

What is the logic behind having the CV and CC indicators under the "Set" label? The user doesn't set CV and CC, so shouldn't they be under "Measured"?

[TimNJ]

I agree. I put them there because I wanted to use the empty created by the lack of Watts set. ON, CV, and CC are just indicators. Haven't thought of a way to separate them from the rest of the display without being awkward. Perhaps another separator line.

[ataradov]

Leave an empty space in the set part (may be add preset indicators there?). And move CC, CV and ON/OFF to the right vertically, where they are located virtually on any power supply.

I also don't like too bright units, I know that voltage is measured in volts, no need to yell. Yet I'd like to be yelled at about CC/CV stuff.

[TimNJ]

Leave an empty space in the set part (may be add preset indicators there?). And move CC, CV and ON/OFF to the right vertically, where they are located virtually on any power supply.

I also don't like too bright units, I know that voltage is measured in volts, no need to yell. Yet I'd like to be yelled at about CC/CV stuff.

Great input! Thanks. Yes, 3 presets under 'Set' and then another column with CV, CC, and ON would definitely make more sense. Will render one up soon.

[EEVblog]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

No, the "point" of this project is for me to produce a commercial quality and commercial looking product I can sell, and have fun doing it.
Yes it may well be "open source" in many respects, but it would be silly to strictly design it around having the ability from a few people (and it is literally a few people, like 0.01% of customers) to be able to make it themselves using all off-the-shelf parts and use that as the driving design factor. That is almost zero on my priority list which is (in rough order):
1) Design a product that I want for myself (and close to my original concept for the uSupply)
2) Design a good looking and well engineered product
3) Design a product that is commercially viable (David2 who is doing a bulk of this work is a full time employee on real professional engineering Australian wages, and this will cost me a lot to design and I want a return on that investment), that means BOM cost matters. I cannot live on advertising money forever so I'm also moving into commercially viable niche products, and that is basically why I hired David full time.
4) Design something that makes for some good video content (custom LCD would make for a good how-to video).
and right down the bottom:
5) Think about were OSHW comes into it.

But ultimately why a custom LCD? Because I think they look better and that's what I want.
Trust me, we have debated for many hours and endless google searching for LCD solutions that might be suitable, and ultimately we think that custom LCD is just nicer, as well as being potentially cheaper and more suited to the case design we have.

You can design a good looking commercial product using all Digikey off-the-shelf parts, but it's ultimately not going to be as nicely polished as what you can do with some custom stuff.
Yeah I can use a nice Newhaven graphic LCD, and have standard Digikey PCB mount tactile buttons through holes in a front panel off-the-shelf box etc etc, the kind of projects you get in Silicon Chip magazine etc, but that's not going to give a nice polished well engineered niche commercial product.

The goal of open hardware should be about learning and sharing of designs and ideas, not making sure every product can be built 100% identical by just anyone.

If you have not seen my video, there are many aspects to OSHW, it's not just some ideal uptopian thing of everything is free and readily available:

[KNSSoftware]

Is this not suppose to be an open source project though?  As much as I would love to follow the experience of getting a custom display designed and produced, does it not go against the point of this particular project, if we can't build our own one without buying one of your custom displays?

No, the "point" of this project is for me to produce a commercial quality and commercial looking product I can sell, and have fun doing it.
Yes it may well be "open source" in many respects, but it would be silly to strictly design it around having the ability from a few people (and it is literally a few people, like 0.01% of customers) to be able to make it themselves using all off-the-shelf parts and use that as the driving design factor. That is almost zero on my priority list which is (in rough order):
1) Design a product that I want for myself (and close to my original concept for the uSupply)
2) Design a good looking and well engineered product
3) Design a product that is commercially viable (David2 who is doing a bulk of this work is a full time employee on real professional engineering Australian wages, and this will cost me a lot to design and I want a return on that investment), that means BOM cost matters. I cannot live on advertising money forever so I'm also moving into commercially viable niche products, and that is basically why I hired David full time.
4) Design something that makes for some good video content (custom LCD would make for a good how-to video).
and right down the bottom:
5) Think about were OSHW comes into it.

But ultimately why a custom LCD? Because I think they look better and that's what I want.
Trust me, we have debated for many hours and endless google searching for LCD solutions that might be suitable, and ultimately we think that custom LCD is just nicer, as well as being potentially cheaper and more suited to the case design we have.

You can design a good looking commercial product using all Digikey off-the-shelf parts, but it's ultimately not going to be as nicely polished as what you can do with some custom stuff.

The goal of open hardware should be about learning and sharing of designs and ideas, not making sure every product can be built 100% identical by just anyone.

If you have not seen my video, there are many aspects to OSHW, it's not just some ideal uptopian thing of everything is free and readily available:

Dave thanks for your considered reply.

While I hope that it doesn't set a fashion for members of the open source community to rush out and start adding custom components into designs; my biggest oversight and acceptance is that you rightly have commercial drivers, and this turns out to be a commercial product, which is appreciable; you have to pay the bills.  You are just sharing the ins and outs.  I must have missed that bit.

I am not trying to blow smoke up your clacker, but i am genuinely enjoying seeing this baby grow - albeit the long haul.

[EEVblog]

While I hope that it doesn't set a fashion for members of the open source community to rush out and start adding custom components into designs; my biggest oversight and acceptance is that you rightly have commercial drivers, and this turns out to be a commercial product, which is appreciable; you have to pay the bills.

The vast majority of OSHW products are not polished finished commercial products.
If you want a really good looking and feeling commercial (or even hobby) product then there is a very good chance that you will have to go custom on some things.
And BTW, the LCD will not be the only custom thing on this design, and once again there are design reasons for this.

[Monkeh]

And if it's open source, and people want to build one, and they don't want to try and get one of your custom LCDs.. well, it's open source. They can change the design, put a graphic LCD in, and change the display code to use it. Yay, open source.

It's about learning, sharing, and adapting, not outright copying.

[jaycee]

And if it's open source, and people want to build one, and they don't want to try and get one of your custom LCDs.. well, it's open source. They can change the design, put a graphic LCD in, and change the display code to use it. Yay, open source.

It's about learning, sharing, and adapting, not outright copying.

This. I'm glad someone else finally gets it.

If the project is open source there is absolutely NOTHING to stop someone committing code which can drive a regular graphic LCD, or 7 segment LED, or whatever you want. Dave's custom display makes no difference.

This is EXACTLY why designers dont open their designs. Too many entitled whiners.

[wilfred]

And if it's open source, and people want to build one, and they don't want to try and get one of your custom LCDs.. well, it's open source. They can change the design, put a graphic LCD in, and change the display code to use it. Yay, open source.

It's about learning, sharing, and adapting, not outright copying.

Some people might just want to make one themselves. That's why the design files (all of them) are made available on open source projects. People who make their own copy ought not be regarded as lesser members of the community than those who can, or want to make changes. Outright copying is perfectly valid. It certainly isn't an issue with software.

A custom component on what is claimed to be open source hardware may just be a way to hinder copying on a commercial scale and confine people to maybe only making firmware changes to single sourced commercial hardware.

I regard true open source as facilitating the copying of the device. That way those who want one can make it and those who see a way to make improvement or modifications can do that and share it. In that way the community can set in train a process of evolution that leads to a place the original make may not have envisaged. Successful open source projects share that in common. The ones that attempt to make sharing more difficult face a steeper hill to climb. That gradient may be custom components, binary-blobs, design files in proprietry formats or single language documentation.

[jaycee]

Some people might just want to make one themselves. That's why the design files (all of them) are made available on open source projects. People who make their own copy ought not be regarded as lesser members of the community than those who can, or want to make changes. Outright copying is perfectly valid. It certainly isn't an issue with software.

A custom component on what is claimed to be open source hardware may just be a way to hinder copying on a commercial scale and confine people to maybe only making firmware changes to single sourced commercial hardware.

I regard true open source as facilitating the copying of the device. That way those who want one can make it and those who see a way to make improvement or modifications can do that and share it. In that way the community can set in train a process of evolution that leads to a place the original make may not have envisaged. Successful open source projects share that in common. The ones that attempt to make sharing more difficult face a steeper hill to climb. That gradient may be custom components, binary-blobs, design files in proprietry formats or single language documentation.

Dave can quite easily provide you with the specs for the display, and you can go and have the display made yourself. Then it's still open source.

[wilfred]

Dave can quite easily provide you with the specs for the display, and you can go and have the display made yourself. Then it's still open source.

I'm not talking about this device. I read a few posts earlier where Dave categorically states his position  on making this an OSHW project.

He says.

 "and right down the bottom:
5) Think about were (sic) OSHW comes into it."

And if you read his first four items in the list it is pretty bloody clear.

So I was responding to another post which amongst other things is  either indirectly or intentionally confusing this projects aims and making a judgement I disagree with about the nature of OSHW.

Specifically that those who copy an OSHW design to make one for themselves are not entering in to the true spirit of OSHW. And secondly that claiming this project is open source when Dave has basically said right at the bottom of the list is considering OSHW aspects.

[EEVblog]

I regard true open source as facilitating the copying of the device.

That's a nice ideal, but not practical in many circumstances.

That way those who want one can make it and those who see a way to make improvement or modifications can do that and share it.

Which is in practice a fraction of a percent of people will will ever use/buy/build the product.

In that way the community can set in train a process of evolution that leads to a place the original make may not have envisaged.

Having custom parts does not prevent that. In the case of this PSU for example, people might take the circuit and use different case which might mean a different display choice anyway, or they might want to change the display as part of the project evolution etc

Successful open source projects share that in common.

Exclusively? Really? Got proof of that?

The ones that attempt to make sharing more difficult face a steeper hill to climb. That gradient may be custom components, binary-blobs, design files in proprietry formats or single language documentation.

Once again, got proof of that?, or is that just your opinion?

What if custom parts are the only way to make the product better? Do you forgo a better and more usable or cheaper or whatever product just because of some arbitrary open source hardware ideal using "off-the-shelf" parts?

Please go design a truly open source hardware (as you envisage it) handheld multimeter for example, and see what kind of usable product you get out it...

[Dubbie]

I really like what Whales came up with.

Good information hierarchy.

[EEVblog]

Specifically that those who copy an OSHW design to make one for themselves are not entering in to the true spirit of OSHW. And secondly that claiming this project is open source when Dave has basically said right at the bottom of the list is considering OSHW aspects.

Questions:
What if I gave you the vector image file for the custom LCD, would you still complain?
Would you like the name of the supplier and the part number so you can take advantage of my tooling cost and order it direct yourself in volume? If so, why? If not, why not?
What if I have a custom case because that makes the product that I am selling better? Would you demand the design files for that? Why? for what purpose?
Would you also demand the suppliers name and the part number so you can make use of my tooling cost for that and order direct in volume? Why? If not, why not?

What if I did extensive videos teaching people how I designed the product, how it works etc etc (above and beyond most OSWH people BTW), and released everything but the custom LCD files, would you still still think I'm not doing things "in the true spirit" of it?

Who adds the most value to the community in this case: me who does all the design videos and teaches people everything in detail but retains the say the LCD file, or someone who provides no such design videos, teaches people almost nothing, and simply puts the same files + the LCD file on a Github repo?

[jaycee]

The way I see it, making the design open source does NOT exclusively mean it is free for everyone to replicate as they wish. More that it is an open design which others can take and build upon, customise to their needs etc.. or even develop mods/improved software for the end devices Dave produces and sells.

I really hope this freetard ecosystem that has plagued software doesnt start to leak over into hardware too.

[wilfred]

Once again, got proof of that?, or is that just your opinion?

No proof, It is just my opinion that OSHW projects that are in a single language or use proprietry file formats and so on, restrict access to those who are fluent in the language or can afford the software eg Altium. Hence the project can't as easily draw input from the widest range of community participants. Hence it is my opinion that the metaphor that it faces a steeper hill to ready acceptance is a valid one. And if I'm wrong, what of it?

But I accept completely that you are making a commercial product and generating interesting (also to me) content for the blog. The original uSupply videos remain a favourite of mine.

[EEVblog]

I really hope this freetard ecosystem that has plagued software doesnt start to leak over into hardware too.

Not sure what you mean by "freetard" but I'm pretty sure I know what you are getting it.
There are already two camps in the OSHW industry, those who want everything to be absolutely open as per the "definition" and will not even entertain the idea that their can be value in something less, and those who are more grounded in the real world.
The former consider my OSHW logo idea video tantamount to sacrilege.

[EEVblog]

Once again, got proof of that?, or is that just your opinion?

No proof, It is just my opinion that OSHW projects that are in a single language or use proprietry file formats and so on, restrict access to those who are fluent in the language or can afford the software eg Altium.

Ok, so what if I designed the uSupply in the choice of OSWH champions, Eagle, but it's a bigger board than the free version can open and you have to pay $$$ for the licenses version to modify it. How is that different to say Altium Circuit Studio that costs about the same?

[Monkeh]

Once again, got proof of that?, or is that just your opinion?

No proof, It is just my opinion that OSHW projects that are in a single language or use proprietry file formats and so on, restrict access to those who are fluent in the language or can afford the software eg Altium.

Ok, so what if I designed the uSupply in the choice of OSWH champions, Eagle, but it's a bigger board than the free version can open and you have to pay $$$ for the licenses version to modify it. How is that different to say Altium Circuit Studio that costs about the same?

Eh what, Eagle is the choice of champions? Okay, it's at least free to look..

I'm an Eagle user, and I think it's a crap choice for OSHW, very nearly as crap as Altium (again, at least you can look with Eagle..)

Oh, you can modify larger boards - it's just XML, after all..

However, IMO, as long as you release entirely up to date schematic PDFs, BOM (to avoid ambiguities), and gerbers, doing it in Altium (or anything else) is acceptable. If you don't.. well, it's not open: People can't even look.

[jaycee]

Not sure what you mean by "freetard" but I'm pretty sure I know what you are getting it.
There are already two camps in the OSHW industry, those who want everything to be absolutely open as per the "definition" and will not even entertain the idea that their can be value in something less, and those who are more grounded in the real world.
The former consider my OSHW logo idea video tantamount to sacrilege.

Yes, the former group. The ones who, for example in Linux complain about the use of firmware blobs in open source drivers. Even if they had the source to the firmware, they wouldn't be able to do anything useful with it and it's more of a "just because".

Open hardware, to me, means you can see the design, derive from some of it, customise it to your own needs, etc.. it does NOT necessarily mean you can 100% clone it yourself. Thats what it should mean.

Incidentally, i'm not a fan of the GPL either. That tends to piss MANY freetards off

[ataradov]

The former consider my OSHW logo idea video tantamount to sacrilege.

Or another idea - if I made it, I chose what I release. If it does not fit some arbitrary definition of "open" - I could not care less. Can't afford the tools I used, don't know the language - too bad. I release tings (HW and SW) for people that know things.

[jaycee]

Once again, got proof of that?, or is that just your opinion?

No proof, It is just my opinion that OSHW projects that are in a single language or use proprietry file formats and so on, restrict access to those who are fluent in the language or can afford the software eg Altium.

Ok, so what if I designed the uSupply in the choice of OSWH champions, Eagle, but it's a bigger board than the free version can open and you have to pay $$$ for the licenses version to modify it. How is that different to say Altium Circuit Studio that costs about the same?

Eh what, Eagle is the choice of champions? Okay, it's at least free to look..

I'm an Eagle user, and I think it's a crap choice for OSHW, very nearly as crap as Altium (again, at least you can look with Eagle..)

Oh, you can modify larger boards - it's just XML, after all..

However, IMO, as long as you release entirely up to date schematic PDFs, BOM (to avoid ambiguities), and gerbers, doing it in Altium (or anything else) is acceptable. If you don't.. well, it's not open: People can't even look.

When there are good open tools to do the work, then proprietary toolsets may go away. Currently, there isnt. No, KiCAD and gEDA are not good tools.
As for visibility, well thats simple. Schematics can be printed as PDF. Board layouts can similarly be supplied as PDF or Gerber. Im sure automated generation of those can be done fairly easily with Altium just as it could with EAGLE.

One advantage to EAGLE is it has a significantly lower cost of entry. Altium is just out of the question for hobbyists.

[Monkeh]

The ones who, for example in Linux complain about the use of firmware blobs in open source drivers. Even if they had the source to the firmware, they wouldn't be able to do anything useful with it

Wanna bet? I have an AP which works mostly okay.. so long as I don't use the vendor-supplied radio firmware. A third party with source access has made huge improvements to it - and if it were open source, many others would assist..

[EEVblog]

Eh what, Eagle is the choice of champions? Okay, it's at least free to look..
I'm an Eagle user, and I think it's a crap choice for OSHW, very nearly as crap as Altium (again, at least you can look with Eagle..)

I was taking the piss a bit, but Eagle is indeed the "defacto" choice of the OSHW industry, many of the major players like Adafruit et.al use it.

Oh, you can modify larger boards - it's just XML, after all..

Yeah, good luck...

[Monkeh]

Oh, you can modify larger boards - it's just XML, after all..

Yeah, good luck...

Don't need it - been there, done that, and not the only person I know who has. The format's actually quite pleasant to work with, it's one of the upsides of Eagle. I've even been through and fixed up entire libraries that way.

[ataradov]

Don't need it - been there, done that, and not the only person I know who has. The format's actually quite pleasant to work with, it's one of the upsides of Eagle. I've even been through and fixed up entire libraries that way.

I actually edit Eagle XML directly for parts as well. It is easier to create MCUs/FPGAs this way. But editing schematics is not going to happen.

[Monkeh]

Don't need it - been there, done that, and not the only person I know who has. The format's actually quite pleasant to work with, it's one of the upsides of Eagle. I've even been through and fixed up entire libraries that way.

I actually edit Eagle XML directly for parts as well. But editing schematics is not going to happen.

It can be done. So can boards. The board's probably the easier - also where you run into size limits.. (okay, multiple schematic sheets are also a problem, I believe).

[EEVblog]

Open hardware, to me, means you can see the design, derive from some of it, customise it to your own needs, etc.. it does NOT necessarily mean you can 100% clone it yourself. That's what it should mean.

I agree, which is why I developed my new creative commons type OSHW logo idea.
But the "official" OSHW organisation does not see it that way, nor do many of the major players (Adafruit et.el) for example.
The problem is many of these OSHW companies have often never actually developed (and put huge $ and time into) any real polished commercial products. They just make bare boards, kits etc, which is great  of course, but then they think that every commercial company should do the same as they do. It a position that lacks any sense of practical commercial reality.

[jaycee]

Open hardware, to me, means you can see the design, derive from some of it, customise it to your own needs, etc.. it does NOT necessarily mean you can 100% clone it yourself. That's what it should mean.

I agree, which is why I developed my new creative commons type OSHW logo idea.
But the "official" OSHW organisation does not see it that way, nor do many of the major players (Adafruit et.el) for example.
The problem is many of these OSHW companies have often never actually developed (and put huge $ and time into) any real polished commercial products. They just make bare boards, kits etc, which is great  of course, but then they think that every commercial company should do the same as they do. It a position that lacks any sense of practical commercial reality.

This is why I refer to GPL as "All your code are belong to GNU". it is basically an ecosystem which does not want developers to get paid to write code.

My attitude to this ? Fuck em. Idealists can preach all they want about everything being free and open - but they still expect to be paid to do work and put food on the table.

[Monkeh]

This is why I refer to GPL as "All your code are belong to GNU". it is basically an ecosystem which does not want developers to get paid to write code.

And yet, most of the big projects have paid developers..

[wilfred]

Specifically that those who copy an OSHW design to make one for themselves are not entering in to the true spirit of OSHW. And secondly that claiming this project is open source when Dave has basically said right at the bottom of the list is considering OSHW aspects.

Questions:
What if I gave you the vector image file for the custom LCD, would you still complain?

I'm principally making a generic point about OSHW  and not complaining because I accept you are placing OSHW at the bottom of the list of considerations for this particular project. But since you ask me directly. I will say that a generic display would make the project IF it was OSHW more readily reproducable to individual makers. A vector image file would help mostly those who wanted to reproduce it on a commercial scale. An individual maker would, if faced with an unavailable custom display probably not bother. Some with stronger skills and motivation may adapt it to a non custom display.

Would you like the name of the supplier and the part number so you can take advantage of my tooling cost and order it direct yourself in volume? If so, why? If not, why not?
What if I have a custom case because that makes the product that I am selling better? Would you demand the design files for that? Why? for what purpose?
Would you also demand the suppliers name and the part number so you can make use of my tooling cost for that and order direct in volume? Why? If not, why not?

Really the same answer applies. All these custom engineered parts make for a better commercial product. But if you were making the product as an OSHW project for a community of individual makers then they form a barrier to those without the resources to exploit them. It is a different argument about whether a project is less OSHW if it is reproducable only in commercial quantities.

What if I did extensive videos teaching people how I designed the product, how it works etc etc (above and beyond most OSWH people BTW), and released everything but the custom LCD files, would you still still think I'm not doing things "in the true spirit" of it?

If you used a custom LCD then I would think it a less accessible OSHW project if making an OSHW project was your aim. If you kept the custom LCD design files secret then I would not consider it OSHW. As I've said in the past it would be a well documented commercial product.

Who adds the most value to the community in this case: me who does all the design videos and teaches people everything in detail but retains the say the LCD file, or someone who provides no such design videos, teaches people almost nothing, and simply puts the same files + the LCD file on a Github repo?

There's a perrenial debate. But like the riddler's riddle on Batman. "when is a door not a door?"
A: " when it's ajar"
If a door is not open then it is closed and the same is true for OSHW. If it is not open then it is closed. Or well documented, but still not open.

But at the end of the day if you are not touting this as an OSHW project I fail to see how a debate about OSHW helps you. I've had this debate with you before when you announced your restricted grades of open classification. I didn't agree with you then and I thought you were being disingenuous and self serving. If you later try to represent this project as OSHW without complete design files then I'll think it again.

However, if you make an entertaining series of videos and a successfull commercial product then I wish you good luck. Maybe I'll even buy one, and be glad of the good doco that accompanies it.

[EEVblog]

Who adds the most value to the community in this case: me who does all the design videos and teaches people everything in detail but retains the say the LCD file, or someone who provides no such design videos, teaches people almost nothing, and simply puts the same files + the LCD file on a Github repo?

There's a perrenial debate. But like the riddler's riddle on Batman. "when is a door not a door?"

No, it was a simple question asking you who is providing the most value to the community.
If you don't want to answer then that's fine.

I'm done talking about OSHW though, it is essentially off-topic for this thread.

[TimNJ]

Here's another. I don't know...might be crap...hard (impossible) to judge your own work objectively.

Switched from dark background/light letters to light background/dark letters. Ultimately, I think I prefer light letters on a dark background but I think the contrast won't be good enough especially on a small LCD. Don't have much experience with that though. Black letters might be cheaper/more available...but I have no idea if that's actually true.

This all said I do like Whales design a lot. I just found it a bit confusing/haphazard on first glance. I loaded my design on my phone just to see what it would look like small and I think it's quite reasonable.

[wilfred]

Once again, got proof of that?, or is that just your opinion?

No proof, It is just my opinion that OSHW projects that are in a single language or use proprietry file formats and so on, restrict access to those who are fluent in the language or can afford the software eg Altium.

Ok, so what if I designed the uSupply in the choice of OSWH champions, Eagle, but it's a bigger board than the free version can open and you have to pay $$$ for the licenses version to modify it. How is that different to say Altium Circuit Studio that costs about the same?

The more accessible the design is to people the better. I'm less interested in the debate about the cost of tools and entirely uninterested in confining things to strictly open source toolchains. I approach the debate about OSHW from the point-of-view that someone WANTS others to reproduce and exploit it. If it looks like they are keeping something secret  then it looks like they don't want it reproduced and hence I start to consider the design closed. The more they want to have people get involved the more likely  the barriers will be lowered. But throwing a design out there in expensive proprietry tool is OK with me.

I think the debate about open-closed is unresolvable by ordinary practical people so looking at it from the POV of the likely intent of the designer will get you a good approximation. If some design info is available to be published but isn't then I'd stick solidly with calling the project closed. If everything is available but unusable to ordinary makers then I'd say who cares it is as good as closed.

[EEVblog]

Since you're doing it for commercail gain I don't see it as such a simple question.

It's very simple, I'll do whatever I want, release whatever I want, and use my OSHW logo idea however I want, the end.
Can we please stop the OSHW discussion now.

[Monkeh]

How very dare you do what you want with your own work. It's unthinkable.

[boffin]

Please please please make the decimal points bigger

(and at least line up the watts under the volts/amps)


More like this

[floobydust]

About the LCD display. I have questions about the requirements.
I thought to work towards getting concrete numbers from a vendor like gpeg, instead of speculating.

Size? Direct-drive or muxed? Pins on the edge or zebra strips?
5V drive or do we have a charge pump LCD driver.
Transreflective or trans fluid for 100% backlit led use.

Cost hit from using many mcu pins/LCD driver may cause a cheap simple display to cost more in the end.
Added plastic parts needed for diffuser or edge lit. Added mounting plastic bezel if zebra strips verses dip pins. So consider the whole display assembly+driver might be a hassle verses using an off the shelf graphic display with SPI. You'd have to do a bill of materials costing for this to compare.

I like negative contrast and the layout improvements by Whales and others.

[mariush]

I was also thinking about that ... how many commons / anodes / cathodes such a display would have, how you're gonna multiplex those segments and still have some nice contrast

I was wondering if you couldn't just use some of these existing 8 digit 14 segment things (2$ each for 1000pcs) : https://www.digikey.com/product-detail/en/varitronix/VIM-878-DP-FC-S-LV/153-1113-ND/1118603  (or bigger ones for 3.3$ for 1000pcs

You have 8 digits, and you can write "A" or "V" on the 8th digit and use 6 digits for numbers, and you could also have  CV and CC  using two digits on a 3rd row where you'd also write the watts value.
And you wouldn't even have to connect all the segments for all the digits. If you're only gonna show numbers on first 6 digits, then you'd  have less traces to connect to your microcontroller or what's gonna be used.

[ataradov]

If I'm not mistaken, LCD manufacturers offer COG controller, so you get a nice SPI interface to the display. Not sure how much it adds to the cost.

Driving this thing from am MCU will require 100-pin package, and is probably not going to be cheap.

[EEVblog]

If I'm not mistaken, LCD manufacturers offer COG controller, so you get a nice SPI interface to the display. Not sure how much it adds to the cost.

A quote we got was $2 extra.

Driving this thing from am MCU will require 100-pin package, and is probably not going to be cheap.

30 cent driver chip.

[A Hellene]

Dave, though Nokia 5110 (PCD8544) is a small LCD (1.6", 84x48px), it is a standard 3-pim SPI (MOSI, SCK, nSS), transflective, sun-readable, extremely low power and quite cheaply available display. You can even use two of them...!

If you need more display real estate, there will always be the SPI TFTs, ranging from 1.8" 128x160px (like the one connected to the breadboard, depicted at the top right of the pictures at the link above) to any dimension & resolution you might wish.


-George

[janekm]

Since I've been there/done that on custom LCD manufacturing (new batch of a design the previous supplier wasn't able to delivery at a reasonable cost / lead time), I can add a few points based on my conversations with a LCD factory (the factory was referred to me by my assembly house, as I wasn't quite willing to take the gamble on a "random" supplier):

• It's a really cut-throat market with a lot of competition to drive prices down. The factory owner I spoke to said that some of his competitors use factory labor to get labor costs down.
• The batch size of the factory I used is 5000 units, and their whole process is set up around that, so they totally hate doing anything not divisible by that. They did end up agreeing to do 3000 but really didn't like it.
• Turnaround time is 1 - 1.5 months, and they can't speed it up due to the many process steps.
• They were able to make samples to show that everything is correct (about 20 from what I remember). It seems these don't go through the regular factory process (they did end up looking slightly different and had a bit of a "hand-made" feel about them). Took about 3 weeks from what I recall.
• There are options regarding viewing angle range, contrast ratio etc. I told them I wanted the best visibility they could make and paid them a premium for that. They delivered, the displays are excellent.
• Cost was of course much lower than the previous US-sourced version, but I wasn't concerned with driving it to the bottom, quality was more important.

Dave, happy to give you a reference to the factory we used, though they only speak Chinese...

[Towger]

I would prefer a good generic LCD display, even if it costs more. (Within reason.)  But I can see the point in going custom.  It is cheaper in 'higher' volumes and reduces the lightly hood/time for Chinese closes to appear.

I told them I wanted the best visibility they could make and paid them a premium for that. They delivered, the displays are excellent.[/li][/list]

 

There is nothing worse than a poor display.

The Whales/boffin design is clearer than the original version.

The TimNJ is also good, if the cost of the larger screen is possible.

[julianhigginson]

Open source discussion derailment aside, it's an interesting project to attempt. Lots of cheap power supply options out there now, so I guess you won't be competing on price? Keen to see what the deal is...

Those of you who want the fully hackable/self-sourcable supply made with a more generic LCD should look into the crowd funded one that shipped the other month...

[EEVblog]

Open source discussion derailment aside, it's an interesting project to attempt. Lots of cheap power supply options out there now, so I guess you won't be competing on price? Keen to see what the deal is...

Yep, it's novel, nothing else on the market like it.
It won't be for everyone.

[xani]

Any tease about what exactly it will be ?

Aside from that, I realized that the "first" idea of uSupply (portable battery-powered lab PSU) now could be done by just putting that chinese DPH3205(that one in particular because of buck-boost mode) module in a box with Li-ion battery + charger (altho it would be ~twice as big)

Those of you who want the fully hackable/self-sourcable supply made with a more generic LCD should look into the crowd funded one that shipped the other month...

which one ? I've been looking for something like battery powered power supply that could double as battery/phone charger (which could probably be easily hacked in into existing design if code was available)

[JPortici]

i'll be curious to see the result.
There's been a product i always wanted to convert to a slim form factor, full screen type for display and user interaction.
The display has to be readable from every light condition (to be placed near the steering wheel)
Unfortunately the available choice of OLEDs don't satisfy me, i should use a smartphone type display but they are tricky to get to..

but then i saw of this microchip demo board http://www.microchip.com/promo/pic16f19197-low-power-touch-enabled-lcd-demonstration
and i wondered if a custom LCD was the right solution.. might be.
I've seen some photos of the actual board and the result is astounding, but i can't get my hands on it yet..

The priority of this project is sub-zero so i'll wait and see your experience in custom LCD manufacture

[Corporate666]

Horizontal bargraph for current would be good.

You should also put the EEVBLOG hand logo on there, because you can.

I'd be really interested in finding out about the process of getting a custom display made - tooling costs, unit costs,MOQ, leadtime, design rules etc.

Just as a datapoint, I had a custom LCD made years ago (must have been 15 years back) by Excel Tech (now Excel Display http://www.excel-display.com/).   It was for an automotive tachometer, and had a bar graph arranged in a crescent shape with numbers in the center. 

I don't recall the exact unit price, but it was under $4/ea in quantities of 1000.  There was a $3000 tooling charge.  This included the driver chip (embedded on the edge of the panel) and the module had a flex cable mounted on it.  I don't recall specific design rules, but I originally wanted the module to be round.  Back then, nobody was doing round LCD's, so they suggested flat cuts on the corners... ultimately we ended up with a 10-sided polygon to approximate a circle.  The only issue I ran into that caused a rework of my intended design was 'orphaned' segments in the center of the display that they weren't able to route out.  Lead time was 3-4 weeks from payment received until first unit samples received, and another 3-4 weeks to produce the whole batch.  Could have gotten them faster but I wasn't in a rush.



Dave, definitely interested to hear your experiences!

[The Soulman]

Assuming this isn't going to be a high-power supply, I'd like a current readout in mA and power in mW.
And actual readings bigger than the set voltage and current, a led to indicate for cc/cv would be a nice bonus.

Another "novel" idea is to be able to link multiple of these psu's in some (galvanic separated..) way for simultaneous output on/off. 

[hugo]

What do you think about this one:

[ataradov]

What do you think about this one:

I like this the most out of all versions here.

[julianhigginson]

Those of you who want the fully hackable/self-sourcable supply made with a more generic LCD should look into the crowd funded one that shipped the other month...

which one ? I've been looking for something like battery powered power supply that could double as battery/phone charger (which could probably be easily hacked in into existing design if code was available)

sorry - not battery powered... I didn't realise this was dave's intention for this product.


The fully DIY friendly option for a bench supply is this guy:
https://www.eevblog.com/forum/crowd-funded-projects/preparing-eez-h24005-for-crowdfunding/
all firmware and hardware is open source.

[ebclr]

Small and very cheap LCD

[xani]

Those of you who want the fully hackable/self-sourcable supply made with a more generic LCD should look into the crowd funded one that shipped the other month...

which one ? I've been looking for something like battery powered power supply that could double as battery/phone charger (which could probably be easily hacked in into existing design if code was available)

sorry - not battery powered... I didn't realise this was dave's intention for this product.


The fully DIY friendly option for a bench supply is this guy:
https://www.eevblog.com/forum/crowd-funded-projects/preparing-eez-h24005-for-crowdfunding/
all firmware and hardware is open source.

Ah yes I saw that one. I looked, said "no knob, no service" and ignored it. The last thing I want from my bench supply is some wonky touchscreen

[Kalvin]

Just make sure that the power supplies share common ground / 0V and not that low side current measurement sh*t.

[VEGETA]

Just make sure that the power supplies share common ground / 0V and not that low side current measurement sh*t.

As long as I remember, he uses only one channel and it doesn't have low side current measurement.

Ah yes I saw that one. I looked, said "no knob, no service" and ignored it. The last thing I want from my bench supply is some wonky touchscreen

It is good to have different opinions, but for me the TFT screen is a big plus! 

It makes it modern and gives a lot of options unlike traditional buttons. It inspired me to do my own power supply using a TFT too, but Dave design inspired me about the battery powered feature. I still didn't manage to make a PCB for the prototype.

[free_electron]

make sure to have dual color backlight. if a fault condition occurs i want the display backlight color to switch to red. ( and blink if possible  like 50% on , 100% on , not full on / off)
Also  think about colorblind people.  make sure there is a huge difference between red and green ! too many dual color led's are indiscernable for colorblind people.

[Maxlor]

I'm looking forward to hearing about the design/manufacturing process for custom displays as well!

As a general point that applies to all the screen layouts above: please use a more prominent decimal point. With the very narrow digit spacing, the decimal point becomes hard to see if it's this small (to test: use a reduced resolution image, or squint, or glance at the display for less than a second.) Adding a bit more space between digits so the decimal point is more visually distinct, or increasing it's size, or both would be a good fix.

Also, the display for the set display should be less prominent than the current display, so the user is less likely to mix them up accidentally. Dave's original design accounts for this nicely.

[julianhigginson]

Ah yes I saw that one. I looked, said "no knob, no service" and ignored it. The last thing I want from my bench supply is some wonky touchscreen

1) the last stretch goal added a knob!

2) it's open source... You want to adjust the design with knobs? Add them! :-)

[kalel]

I haven't used any lab power supplies yet, so mine is an inexperienced opinion. I would also prefer knobs, either the multi turn stuff or encoders, versus physical buttons.

I don't know about reliability differences, micro switches have their limits too (if you had to press them all the time to adjust parameters).

As for a pure touchscreen solution - it also sounds difficult to use. I haven't checked the specific product, just generally. If you had one with only touchscreen, could you e.g. decrease current to test the brightness variation in an LED without looking at the screen? You might be able to program a current sweep in a modern supply (I don't know if you can, but I don't see why not), but I would still prefer the knobs.

[fcb]

Forget putting the Watts calculation on the screen - of little actual use unless you have bigger plans for the unit.

Use the space to put a couple of symbols, like battery state for the LiIon and maybe your logo (when it boots up).

[NivagSwerdna]

My ideal uSupply would allow me to charge my Li Ion cells.... and on completion it would show me how many mAhr it had pumped in to them.

So it would have "hr" as a segment and possibly also "Complete" or "Done"

Possibly also time in MMM:SS as it charges

Just sayin'

[ataradov]

My ideal uSupply would allow me to charge my Li Ion cells.... and on completion it would show me how many mAhr it had pumped in to them.

Why would you want to charge batteries from a portable battery-based device? Seems like a huge waste. What you want is a good battery charger.

[mikeselectricstuff]

I think it would be worth putting an H after the W and A , for possible other uses like a dummy load, though would also be occasionally handy on a PSU for estimating battery life

[NivagSwerdna]

My ideal uSupply would allow me to charge my Li Ion cells.... and on completion it would show me how many mAhr it had pumped in to them.

Why would you want to charge batteries from a portable battery-based device? Seems like a huge waste. What you want is a good battery charger.

You need more imagination.  The display could be used for a variety of purposes...  and thanks Mike... "Hh" works

[ataradov]

You need more imagination.  The display could be used for a variety of purposes...

That's a recipe for a project that never ends.

[MT]

Custom LCD proposal for the new µSupply
Comments foolishly invited

And the mm dimensions are?

[asmi]

Personally I'd prefer full LCD display if only to make the device more customizable via firmware changes.

[ebclr]

Why not an easy programmable color serial LCD ( HMI ) like this one,  cost is approx 5 USD, no tooling no nothing, and design can be changed at any time the software guy wants

[Mr. Scram]

Why not an easy programmable color serial LCD ( HMI ) like this one,  cost is approx 5 USD, no tooling no nothing, and design can be changed at any time the software guy wants

That's a $15 screen by the time it reaches the customer. The quality seems unknown.

[Whales]

Be very wary of that product shot.  The screen's picture looks absolutely perfect, with pure blacks and perfect whites, even better than the contrast of the rest of the photo.

[ataradov]

Be very wary of that product shot.  The screen's picture looks absolutely perfect, with pure blacks and perfect whites, even better than the contrast of the rest of the photo.

The picture is obviously photoshopped, I thought it was obvious to everyone.

[julianhigginson]

Why not an easy programmable color serial LCD ( HMI ) like this one,  cost is approx 5 USD, no tooling no nothing, and design can be changed at any time the software guy wants

because there's about 3 pages discussing that in the thread already and dave has explained why not multiple times?
 

[EEVblog]

Latest version:

[ataradov]

Latest version:

Looks great, IMO. What are the dimenstions?

[Dubbie]

Nice Dave.

Can you fix the kerning on the mJ and Wh. It will help legibility and look more polished.

[Mr. Scram]

That already looks a lot more mature than the previous version. I like the increased legibility of the things in solid blocks.

I do notice that the MIN/MAX aren't sized the same on the volt side of things. That should of course be a minor fix.

[asmi]

Latest version:

Not sure if it's possible, but it would be awesome if volts and amps would have different colors. Never underestimate the value of a quick glance! 

[Mr. Scram]

Not sure if it's possible, but it would be awesome if volts and amps would have different colors. Never underestimate the value of a quick glance! 

Considering those colors seem to be different on different equipment, I think you need a second look anyway. After a handful of uses, you should know whether the upper indicator is volts or amps.

[jaycee]

Latest layout looks great, and has a multitude of uses. Maybe you'd even consider selling them individually for those of us brewing our own PSU's too ?

[Seppy]

Nice Dave.

Can you fix the kerning on the mJ and Wh. It will help legibility and look more polished.

I didn't even notice the kerning problem, it happened in the conversion from vector artwork to png. Weird.

That already looks a lot more mature than the previous version. I like the increased legibility of the things in solid blocks.

I do notice that the MIN/MAX aren't sized the same on the volt side of things. That should of course be a minor fix.

Yeah that was fixed, forgot to update the section with the MIN/MAX template.

Thanks everyone!

[mariush]

Not sure I dig the single "inverted" icon on the right, the ON text... it's like it makes everything off balance.  I like things vertically aligned and symmetric.

Wonder if it wouldn't look better on the left in the same shape as the CV and CC icons and then have that whole row moved to the right and have 0 instead of 1 (should fit, since the ON would be slightly smaller) .. why have just "1" there when everything else is full 7 segment

Speaking of which, wouldn't the controller they put on the back of the lcd display have some limitation about the number of segments and all that? Are there price jumps depending on the segment count ?

Looks like around 160 segments to me (just multiplying the digits by 7 segments, adding dots and all that)... 

[Seppy]

Not sure I dig the single "inverted" icon on the right, the ON text... it's like it makes everything off balance.  I like things vertically aligned and symmetric.

We thought ON was perhaps the most important display icon, this is why it stands out the most and on its own.

[VEGETA]

If it is custom, how can you drive it via MCU? I mean, will it be the same like other LCDs?

[ataradov]

If it is custom, how can you drive it via MCU? I mean, will it be the same like other LCDs?

LCD controller chip. This was already mentioned in this thread.

[EEVblog]

Speaking of which, wouldn't the controller they put on the back of the lcd display have some limitation about the number of segments and all that? Are there price jumps depending on the segment count ?

This is not a COG display, controller is external for cost reasons.
The external controller supports 8 COM x 32

[JPortici]

Or there could be a separate microcontroller for the user interface which also has a segment LCD controller builtin (maybe not in this case but it is another alternative)

[VEGETA]

If it is custom, how can you drive it via MCU? I mean, will it be the same like other LCDs?

LCD controller chip. This was already mentioned in this thread.

I mean, its segments are different than traditional 16x2 LCDs. Can it work with controller chips used with other LCDs? if so, then something like Arduino library is capable of using it but it needs some tweaking to modify segments since they are different than traditional LCDs.

[ataradov]

I mean, its segments are different than traditional 16x2 LCDs.

16x2 LCDs use LCD controllers specifically designed to control displays like that. There are other controllers that just control the matrix of arbitrary segments (in this case 8 x 32 = 256 segments max).

Can it work with controller chips used with other LCDs?

It is a bare glass, it can be used with any controller capable of driving enough segments (and that specific arrangement of segments).

if so, then something like Arduino library is capable of using it but it needs some tweaking to modify segments since they are different than traditional LCDs.

That's Arduino problems.

[mikeselectricstuff]

No room/segments for a bargraph? A current bargraph would be a handy feature on a PSU.

[NivagSwerdna]

Other than a linear display aka bargraph the latest version looks great.

[Dubbie]

Just curious what would a bar graph be good for? Faster response so you can see current bouncing up and down?

[ataradov]

Just curious what would a bar graph be good for? Faster response so you can see current bouncing up and down?

It would be useful to see how close you are to a set current before CC kicks in.

[mikeselectricstuff]

Just curious what would a bar graph be good for? Faster response so you can see current bouncing up and down?

Yes.
This is hard to see on a digital display, even one that updates quickly.

[stmdude]

Just curious what would a bar graph be good for? Faster response so you can see current bouncing up and down?

Yes.
This is hard to see on a digital display, even one that updates quickly.

Ooohh.. Old-school VU-meter "peak-hold" functionality would be awesome for getting an idea of inrush-currents and peaks.

[xani]

New version looks nice, altho knowing what uSupply will actually do aside from current limit + power/charge calculation would be helpful

Ooohh.. Old-school VU-meter "peak-hold" functionality would be awesome for getting an idea of inrush-currents and peaks.

Let the scope creep begin At that point probably graphical LCD would make more sense and then you can just graph it, or just... display as text ("Ipp/Vpp in last minute", Iavg, Ip-p etc.)... and if you need those you might want to export it via serial or save somewhere and are probably few $ more in parts count and outside scope of the project 

[The Soulman]

Latest version:

Couldn't move the lock and add a m above the V and A?
I'd personally find 1 mA more pleasant to look at than 0.001 A,
and if hardware allows you could go down to 0,1 mA or even lower, much more practical for dealing with small electronics projects.

[ataradov]

I'd personally find 1 mA more pleasant to look at than 0.001 A,

"1 mA" and "0.001 A" have very different meaning. I doubt this thing will have multimeter-quality frontend, so its accuracy at low currents is not going to be super high.

and if hardware allows you could go down to 0,1 mA or even lower, much more practical for dealing with small electronics projects.

Use multimeters.

Stop with the feature creep. That's how 99% community projects die.

[The Soulman]

I'd personally find 1 mA more pleasant to look at than 0.001 A,

"1 mA" and "0.001 A" have very different meaning. I doubt this thing will have multimeter-quality frontend, so its accuracy at low currents is not going to be super high.

(000)1 mA is still the same as 0,001 A and IMHO more practical for smaller electronics.

and if hardware allows you could go down to 0,1 mA or even lower, much more practical for dealing with small electronics projects.

Use multimeters.

The whole point of this uSupply is it's small size and practicality, the need of adding multimers to get some half accurate readings almost defeats having a read-out on the display at all and would take away a large selling point.

Stop with the feature creep. That's how 99% community projects die.

I don't think it is a community project, Dave posted a couple of drawings for us to shoot at, in the end it is going to be a commercial product.

[ataradov]

The whole point of this uSupply is it's small size and practicality, the need of adding multimers to get some half accurate readings almost defeats having a read-out on the display at all and would take away a large selling point.

And you can estimate and order of magnitude just fine. If you need an actual measurement - use measurement tools. All in one never works well.

I don't think it is a community project

Me neither, but this demand for random features is very indicative of community projects. And in this case only one aspect was exposed, and people suggest the device should do all that things they want.

[mikeselectricstuff]

Maybe an auto/manual range indicator.
Perhaps also remote/comms indicator if there is an interface (though could maybe use (flashing) padlock.

[mariush]

Also , if this is a product that may be optionally working from battery only (disconnected from mains), maybe it would make sense to have a low battery voltage indicator

[KE5FX]

https://youtu.be/WoRJOCdNahc?t=17m38s

'Nuff said. 

(I can't figure out how to embed the video, but the link goes to a relevant spot in the John Kenny interview.)

[ataradov]

'Nuff said. 

If this thing had VFD, he would have justified that as well. That's called marketing.

[KE5FX]

'Nuff said. 

If this thing had VFD, he would have justified that as well. That's called marketing.

In 2010 you might be able to argue the point one way or the other.  In 2017, no.

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

[mikeselectricstuff]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

..or you care about power consumption.
Or long-term security of supply
Or cost.
Or sunlight readability.

[KE5FX]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

..or you care about power consumption.
Or long-term security of supply
Or cost.
Or sunlight readability.

I'm skeptical about the middle two, certainly.  When you design something with a weird part -- and a custom LCD is certainly a "weird part" -- you are at the mercy of your supplier, specifically future changes to their minimums and lead times.  Cost-wise, the best way to attack that problem is just to assume that you'll have to hit alibaba.com every so often to find the next big load of surplus panels that someone's dumping on the market. 

Power consumption... well, it's a power supply, isn't it?

Sunlight readability was one of the many Achilles' heels that was going to sink the iPhone, as I recall.

(Edit: yes, I know, the decision's made and no longer open to debate, which is fine.  But I couldn't resist posting the link to the Kenny interview, since Dave seemed so receptive to his point at the time.)

[NivagSwerdna]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

Actually this is an EEVBlog project.  The revenue from the video discussing the making of the custom LCD will probably cover the cost. I'm looking forward to seeing the video.

[jbb]

I think that’s a good start.

Custom character LCDs really are great for visibility and clarity, especially under variable lighting conditions. Plus they use a lot less power (which may or may not be relevant here.)

On the multi-colour backlight front, do remember that there are colourblind people out there.

Assuming you’re not running into trouble with segment count, I would suggest the following (most useful to least IMHO):
- Error
- CP (constant power)
- Over currrnt trip
- Over voltage trip
- Remote
- Ohm, kOhm indicators (in case someone wants to make a uLoad)

As others have suggested, a bar graph could be nice but isn’t critical.

Edit: removed stuff that was already done (I was late to party...)

[KE5FX]

As others have suggested, a bar graph could be nice but isn’t critical.

I really like the bar graph idea.    I always want to know how close I am to my preset current limit, but none of my bench supplies presents that information in an easy-to-read form.

[max_torque]

Nice Dave.

Can you fix the kerning on the mJ and Wh. It will help legibility and look more polished.

I didn't even notice the kerning problem, it happened in the conversion from vector artwork to png. Weird.

That already looks a lot more mature than the previous version. I like the increased legibility of the things in solid blocks.

I do notice that the MIN/MAX aren't sized the same on the volt side of things. That should of course be a minor fix.

Yeah that was fixed, forgot to update the section with the MIN/MAX template.

Thanks everyone!

From a intuition point, i'd have MAX above MIN (rather than the otherway around) on the display.  In fact, i might have:

MAX
CC
MIN

to make it even more intuitive

[ataradov]

From a intuition point, i'd have MAX above MIN (rather than the otherway around) on the display.  In fact, i might have:

MIN/MAX segments will never be seen at the same time. What difference does it make?

[max_torque]

Because you will be able to intuitively know if it's a max or min by it's position, rather than actually have to read the text!

Like on an analogue meter.  If the needle is hard over to the rhs of the gauge, it's bad, you don't need to actually read what the needle is pointing too!  On a mono colour display, simple physical positioning for intuition makes a big difference ime

[mikeselectricstuff]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

..or you care about power consumption.
Or long-term security of supply
Or cost.
Or sunlight readability.

I'm skeptical about the middle two, certainly.  When you design something with a weird part -- and a custom LCD is certainly a "weird part" -- you are at the mercy of your supplier, specifically future changes to their minimums and lead times.

Worst case you can take your design to another supplier, with suitable MOQ/leadtimes.
Custom glass is cheap once tooled, so you can afford to keep a decent amount of stock

Cost-wise, the best way to attack that problem is just to assume that you'll have to hit alibaba.com every so often to find the next big load of surplus panels that someone's dumping on the market. 

And have to redesign due to a different connector or pinout or flex length. If you can still even get the same size and mechanical mounting detail. And take pot luck on quality.

Power consumption... well, it's a power supply, isn't it?

A battery powered one.

[KE5FX]

A battery powered one.

Might be a good application for E-ink, if factors like battery life and readability in sunlight are important.  There are usually plenty of surplus panels on the market. 

Something like this could be a great fit, if the pricing isn't too far out of line.  (Also, you couldn't backlight it if you wanted to, which isn't ideal.) 

Maybe I've missed it -- has anyone posted any actual quotes for custom LCD pricing in the thread?

Edit: hmm, 15 second full refresh time seems a bit excessive.

[mikeselectricstuff]

A battery powered one.

Might be a good application for E-ink, if factors like battery life and readability in sunlight are important.  There are usually plenty of surplus panels on the market. 

Probably not - E-ink is slow, but also has the risk that something's gone wrong/crashed, and the display is still showing 3v when the PSU is outputting 24V.
Basing a production design on surplus parts is also very risky, unless they are so cheap you can buy a reasonable lifetime's worth of stock.

[EEVblog]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

..or you care about power consumption.
Or long-term security of supply
Or cost.
Or sunlight readability.

I'm skeptical about the middle two, certainly.  When you design something with a weird part -- and a custom LCD is certainly a "weird part" -- you are at the mercy of your supplier, specifically future changes to their minimums and lead times.

Worst case you can take your design to another supplier, with suitable MOQ/leadtimes.
Custom glass is cheap once tooled, so you can afford to keep a decent amount of stock

Yes. If the product for example starts selling well in the thousands then you can likely comfortably buy 10k or more stock giving you plenty of time to move the design files to another supplier if needed.

Cost-wise, the best way to attack that problem is just to assume that you'll have to hit alibaba.com every so often to find the next big load of surplus panels that someone's dumping on the market. 

And have to redesign due to a different connector or pinout or flex length. If you can still even get the same size and mechanical mounting detail. And take pot luck on quality.

Yes. All those things factor in. The time and effort and doing that is at least equivalent if not more than simply giving the design files to another LCD manufacturer. Several if you aren't happy with the quality  you get the first time.

[EEVblog]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

Actually this is an EEVBlog project.  The revenue from the video discussing the making of the custom LCD will probably cover the cost. I'm looking forward to seeing the video.

I'm afraid not.
You can argue that my time is "free", but David2 who is doing the bulk of the grunt work is paid real full time engineering wages.
A video with say 50k views only bring in about $75-$100 in ad revenue tops. Even if I did 10 videos on it, it wouldn't pay the wages even up on until this point, and we are hardly into it.

[gamalot]

A few weeks ago I received my custom LCD display and a back-light panel, The LCD display is COG and has only 5 pins on it. 

[Dubbie]

Cool

How many did you get and what was the setup + unit cost?

[EEVblog]

It only makes sense to use an antique fixed-segment LCD if you know you will not face any market competition.  It's a hobby project in that case, not a commercial one.

I think the dot matrix display on this product will make it look more "hobby". A nice clear custom LCD to me has the vibe of "professional design" rather than just "oh, it's an Alibaba matrix display in a box.
And the most important thing, I like segment LCD's and as a bonus it will make an interesting video of the process of doing it.

[gamalot]

I can't remember exactly, the unit price of the LCD is about 20 something, the back-light is about 10 something, CNY.

I think they are cheap enough, the only problem is they asked for a minimum order quantity, which was 6,000 pcs.

[StillTrying]

Latest version:

I quite like that latest version, but no obvious way to indicate when you're viewing/checking Vin or Vbat.

[EEVblog]

I can't remember exactly, the unit price of the LCD is about 20 something, the back-light is about 10 something, CNY.
I think they are cheap enough, the only problem is they asked for a minimum order quantity, which was 6,000 pcs.

Did you order the 6000 or just get samples after paying the tooling?

[KE5FX]

I think the dot matrix display on this product will make it look more "hobby". A nice clear custom LCD to me has the vibe of "professional design" rather than just "oh, it's an Alibaba matrix display in a box.

That obviously wasn't true for the 3446x DMMs.  It's the content and presentation that count, not the choice of display components.... except that one of those component options constrains the content and presentation severely, compared to the other.

Many good ideas have been posted by various people in this thread, none of which can be implemented once you hit 'Send' on the email containing your LCD design files.  That would bug me.

And the most important thing, I like segment LCD's and as a bonus it will make an interesting video of the process of doing it.

That's the only reason that matters, of course.

[EEVblog]

That obviously wasn't true for the 3446x DMMs.  It's the content and presentation that count, not the choice of display components.... except that one of those component options constrains the content and presentation severely, compared to the other.
Many good ideas have been posted by various people in this thread, none of which can be implemented once you hit 'Send' on the email containing your LCD design files.  That would bug me.

Lucky it's not your design and you don't have to worry about it.

[free_electron]

the current display is shared with the power display.
i don't like too much numbers at once.

CC constant current mode
CV constant voltage mode
OV : overvoltage tripped

when rotary dial is turned the appropriate field changes , after 2 seconds : display live value

A 'Set V , Set C , Set OVP button allow you to enter what you want to alter
a FUNC button cycles between Amp / Watt / Joule

The circles around 1 2 3 show you what memory recall is in effect.

Take a look at the U8001 frontpanel from agilent. simplicity and functionality

and i don't like square displays.

[EEVblog]

and i don't like square displays.

Sorry, it's going to be square. It suits the form factor of the packaging.
Bare in mind this product might be entirely different to what some people are expecting.

[Dubbie]

Bare in mind this product might be entirely different to what some people are expecting.

It's a power supply wristwatch!

[xani]

Well it would help if we knew anything aside from what we can guess from front panel

That obviously wasn't true for the 3446x DMMs.  It's the content and presentation that count, not the choice of display components.... except that one of those component options constrains the content and presentation severely, compared to the other.

You can get away with paying few bucks more for screen in ~$1k design than in $50-100 one. Also already mentioned https://www.crowdsupply.com/envox/eez-h24005 and chinese $20 power modules already do that

Take a look at the U8001 frontpanel from agilent. simplicity and functionality

It's just personal preference. For example from my perspective U8001 form factor is utter crap because I prefer tall power supplies over wide, because when you have more than one of them cables do not cover one another

And the knob placement... if you stack one on top of another you have to either route wires away from top unit to the right, or will have to turn the bottom unit knob via wires hanging from the top one  and they left a ton of empty space too, they could fit few direct memory buttons, even my korad have those 

[EEVblog]

Well it would help if we knew anything aside from what we can guess from front panel

Sorry, secret squirrel. It would just lead to an infinite amount more endless debate.

[Towger]

Extra clues on The Amp Hour!

[NivagSwerdna]

I'm afraid not.

That's a shame.  I must have extrapolated too far.  Fair enough

...but David2 ... is paid real full time engineering wages.

Paid! What's the world coming to! 

[VEGETA]

...but David2 ... is paid real full time engineering wages.

I thought the design is ready but needs modifications. Will it be different than the one described in the videos?

[gamalot]

I can't remember exactly, the unit price of the LCD is about 20 something, the back-light is about 10 something, CNY.
I think they are cheap enough, the only problem is they asked for a minimum order quantity, which was 6,000 pcs.

Did you order the 6000 or just get samples after paying the tooling?

I have just talked to my brother (he ordered those LCD and back-light panels), the truth is:

We've paid 6,000CNY for the samples, the unit price is well be about 16CNY/set (LCD + back-light panel) at minimum order quantity of 3,000 sets.

[EEVblog]

I thought the design is ready but needs modifications. Will it be different than the one described in the videos?

Yes, entirely new design.

[VEGETA]

I thought the design is ready but needs modifications. Will it be different than the one described in the videos?

Yes, entirely new design.

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Maybe you used a transistor instead of a ready-to-use regulator?

That would make a pretty nice video!

[Aleksolder]

The variety and quantity of replies might be suggestive that the graphic display is the way to go, despite its shortcomings. With graphics, owners could write their own displays. Even though very few might actually do it, knowing it's possible is a strong selling point, and also frees you from this difficult design decision.

I did this with a process control system that I designed, and suddenly a very contentious issue (among fussy customers and my own team) evaporated. Smiles all around.

[xani]

The variety and quantity of replies might be suggestive that the graphic display is the way to go, despite its shortcomings. With graphics, owners could write their own displays. Even though very few might actually do it, knowing it's possible is a strong selling point, and also frees you from this difficult design decision.

I did this with a process control system that I designed, and suddenly a very contentious issue (among fussy customers and my own team) evaporated. Smiles all around.

 I agree but... we do not know what exactly "new" uSupply is and without that it is hard to say if graphical LCD is something that the few % hacking it will put to good use or something that buyers wont even bother touching because base capabilities will be too limited.

Even then, arguably making product more expensive to make it hackable for tiny % is not a good idea.

[mikeselectricstuff]

Fixed segment display, once finalised, reduces the scope for feature creep...

[free_electron]

Fixed segment display, once finalised, reduces the scope for feature creep...

other side of the sword : fixed segment display holds up development until all is cast in stone....

[RES]

Pervasive e-paper?

https://www.digikey.nl/product-detail/en/pervasive-displays/SW074AS182/SW074AS182-ND/4898789
Not cheap.

[xani]

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

[ebclr]

Real LCD's are not the same as paper LCD, and the real ones are much worse

[VEGETA]

what about power consumption?

How much power a TFT screen 2.4" takes compared to suggested LCD?

[ebclr]

For sure a lot more

[boffin]

Guys, it's Dave's project. He can do it however he wants.

[Mr. Scram]

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

It can easily be more than 1 Hz. People even play console emulators on their Nooks. Also, zero consumption when not updating and partial update is available.

I'm not saying it should be e-ink, but let's be factual

[VEGETA]

For sure a lot more

So it is not suitable for battery-based PSU?

[stmdude]

Guys, it's Dave's project. He can do it however he wants.

If anyone thinks he'll do it any other way than the way he wants, they haven't seen many of his videos.

[Mr. Scram]

If anyone thinks he'll do it any other way than the way he wants, they haven't seen many of his videos.

Dave's more than capable of ignoring other's opinions without our help

[KE5FX]

Guys, it's Dave's project. He can do it however he wants.

You submit a project online for comments, you get comments.  That's how it works. 

[ruffy91]

The secret feature:
It's wirelessly powered!

[EEVblog]

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Yes, the LT3080 had protection and other issues.

[IanB]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

[VEGETA]

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Yes, the LT3080 had protection and other issues.

So now LT3081? or you reverted back to using transistor pass element like npn or n-mosfet?

I have used n-mosfet in my design with sepic pre-regulator (1v dropout) and it worked fine after help of others and countless iterations. I remember you saying that you want an off-the-shelf solution and that is why you picked lt3080, I wonder if you changed your mind now.

In any case, I vote for another video series about the subject  at least one video to explain or walkthrough the circuit.

[wilfred]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

Dave said in post #66

"and right down the bottom:
5) Think about were OSHW comes into it."

This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

If you want to start a discussion on OSHW in another thread people might be interested in considering custom components as part of the equation.

[IanB]

Consider an alternative view though. Many people really like the older test equipment from HP and other manufacturers because they have available full schematics and service manuals. This means that people have a chance to repair and maintain the equipment long after it was made.

Now consider that a problem with custom manufactured parts is that if they fail and need to be replaced an original replacement may not be available. However, even if the actual part cannot be obtained, a documented interface spec may at least permit some kind of equivalent to be constructed.

So my comment is not about OSHW any more than classic items of test equipment were OSHW. My comment is about maintenance and repair by future owners.

[EEVblog]

Dave said in post #66
"and right down the bottom:
5) Think about were OSHW comes into it."
This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

Why don't you drop it Wilfred?
The design will be open, just because it's not in a way you approve of doesn't mean others should drop it.

[wilfred]

Dave said in post #66
"and right down the bottom:
5) Think about were OSHW comes into it."
This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

Why don't you drop it Wilfred?
The design will be open, just because it's not in a way you approve of doesn't mean others should drop it.

Did I say drop it or move it to another thread?  This part of my post that you conveniently left off said:
"If you want to start a discussion on OSHW in another thread people might be interested in considering custom components as part of the equation. "

If anyone does want to discuss the definition of OSHW that I approve of then start up another thread. I haven't made up my own definition. I just use this one here https://www.oshwa.org/definition/
"Open source hardware is hardware whose design is made publicly available so that anyone can study, modify, distribute, make, and sell the design or hardware based on that design."

But I'm not particularly interested in a specific discussion about whether this project is or is not OSHW. It would be hypothetical until the design files are published.

[xani]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

That's a software engineer perspective. Power supply is not just software.

If device has a form factor with a certain display in  mind you can't "just replace it" unless you find one in same size and connector (or possibly smaller). Especially if you are replacing a custom LCD.

So it does make hacking a much less interesting perspective. Now amount of people who hack will probably be pretty small. Like you might get 5% which will install custom firmware, maybe 0.1% which will actually modify code. But the moment you need to fuck around with replacing display you might as well re-do the hardware.

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

It can easily be more than 1 Hz. People even play console emulators on their Nooks. Also, zero consumption when not updating and partial update is available.

I'm not saying it should be e-ink, but let's be factual

Hey I just read that off datasheet from your own link to a product, 100% facts here. E-ink would just be a novel(and have obvious problems that are not that easy to solve unless you buy ready-made one, like backlight), LCD is just much better fit for the job

[fcb]

Some of the e-ink demos I have seen do a full page refresh each time.  I'm not 100% sure if you can easily do a partial refresh (I stand to be corrected) - so lovely quality to the text but not appropriate for a PSU.

When I looked at them for a project they were very expensive, so I didn't bother looking more deeply into the technology.

+1 for a custom LCD

[mariush]

There are other technologies which are sort of like eink but better, here's one example:



It's expensive though.

[aandrew]

I am not a fan of LCDs for instrumentation. Glare, low contrast ratio, low resolution.

Give me graphical OLED or VFD for high end, segmented VFD for mid and plain old regular 7 segment LEDs and illuminated indicators (think icons with an LED behind to light up when they're active) for low end.

graphical LCDs and segmented LCDs are actually a "feature" point that turn me off of selecting an instrument.

[Mr. Scram]

Hey I just read that off datasheet from your own link to a product, 100% facts here. E-ink would just be a novel(and have obvious problems that are not that easy to solve unless you buy ready-made one, like backlight), LCD is just much better fit for the job

That was not my link or proposition. I'm just somewhat aware of the capabilities of the technology. Again, let's be factual.

I don't quite understand the comment about "ready made". LCD would be too, right? The same applies to both technologies.

[Mr. Scram]

Probably not - E-ink is slow, but also has the risk that something's gone wrong/crashed, and the display is still showing 3v when the PSU is outputting 24V.
Basing a production design on surplus parts is also very risky, unless they are so cheap you can buy a reasonable lifetime's worth of stock.

See, that's a real argument. Power supplies have to be safe.

[gardner]

Personally I am another advocate for a bar graph or % of set-current display.  I also want to have the current shown in mA where appropriate.  Here is a craptacular mock-up of a way to shoehorn those features in.

[ZeTeX]

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Yes, the LT3080 had protection and other issues.

When are we expected to get a new video / updated schematic?

[Mr. Scram]

I am not a fan of LCDs for instrumentation. Glare, low contrast ratio, low resolution.

Give me graphical OLED or VFD for high end, segmented VFD for mid and plain old regular 7 segment LEDs and illuminated indicators (think icons with an LED behind to light up when they're active) for low end.

graphical LCDs and segmented LCDs are actually a "feature" point that turn me off of selecting an instrument.

Both VFD and OLED aren't as durable as LCD. They tend to wear out or become unobtainable. Longevity is important in products like these, much more than it is in the mobile phone or general consumer markets.

[VEGETA]

I am not a fan of LCDs for instrumentation. Glare, low contrast ratio, low resolution.

Give me graphical OLED or VFD for high end, segmented VFD for mid and plain old regular 7 segment LEDs and illuminated indicators (think icons with an LED behind to light up when they're active) for low end.

graphical LCDs and segmented LCDs are actually a "feature" point that turn me off of selecting an instrument.

Both VFD and OLED aren't as durable as LCD. They tend to wear out or become unobtainable. Longevity is important in products like these, much more than it is in the mobile phone or general consumer markets.

What about professional bench PSU? what do they use?

I aid your point of longevity but I don't think TFTs, OLEDs, and others are bad. It all depends on your estimated lifespan of the product until it becomes in its late age.

I am still a fan of high quality (and small) touch TFTs with lots of menus and options, EEZ-supply is the way to go and the model to follow here. You can still have your classical rotary encoder though.

Quick important question: what is the price dave wants to tag to this PSU? this answers a lot.

[Mr. Scram]

What about professional bench PSU? what do they use?

I aid your point of longevity but I don't think TFTs, OLEDs, and others are bad. It all depends on your estimated lifespan of the product until it becomes in its late age.

I am still a fan of high quality (and small) touch TFTs with lots of menus and options, EEZ-supply is the way to go and the model to follow here. You can still have your classical rotary encoder though.

Quick important question: what is the price dave wants to tag to this PSU? this answers a lot.

What about professional test gear? Some have used VFD in the past, some have used OLED, and both turn out to be less durable than simpler LED and LCD solutions. You could also argue that you don't care about the gear working over 15 or 20 years, which isn't unfair.

It should be noted that OLED may have had some issues because the technology was new back then and not quite as developed as it is now.

[mikeselectricstuff]

A PSU has simple and mostly obvious UI requirements.
Almost nobody will be interested in hacking it unless the firmware actively sucks.
A custom LCD is almost certainly going to be the cheapest (display+drive hardware+CPU resources to drive it) option if the volumes are there. It also allows more flexibility of shape/size than an off-the-shelf LCD, and therefore more flexibility of panel layout, for optimum space usage of an off-the-shelf case.
 

[julianhigginson]

Well, if anything, this thread has been an awesome reminder of why not to open designs up for contribution before the features are decided...
 

[Mr. Scram]

Well, if anything, this thread has been an awesome reminder of why not to open designs up for contribution before the features are decided...
 

Wasn't that the point? You take the suggestions you like and leave the rest.

[EEVblog]

When are we expected to get a new video / updated schematic?

When it's finished.

[Fire Doger]

Hello Dave,

As a newbie in mass production I am wondering why you don't make a poll about some features which seems to "bug" some members (ex. lcd). It looks like you did a research (referring on Newhaven on older post)

I mean something like:
80-100$ with TFT ++ any other associated features like max current, size etc...
50-70$ with custom lcd ++...

Is it because you are targeting on how you want to look-cost-use and less on profit, the results from that kind of polls are inaccurate or for other reasons?

I am just curious,
Thanks

[EEVblog]

Hello Dave,
As a newbie in mass production I am wondering why you don't make a poll about some features which seems to "bug" some members (ex. lcd). It looks like you did a research (referring on Newhaven on older post)

It doesn't matter what you do you will never be able to please a majority. Product design by poll or public opinion does not work.

[mikeselectricstuff]

Hello Dave,
As a newbie in mass production I am wondering why you don't make a poll about some features which seems to "bug" some members (ex. lcd). It looks like you did a research (referring on Newhaven on older post)

It doesn't matter what you do you will never be able to please a majority. Product design by poll or public opinion does not work.

No it doesn't, though more eyes on a problem can often come up with good ideas or spot things you've not considered - just needs suitable filtering
 

[Mr. Scram]

Design by committee produces the most horrible products. Besides, it's been shown that people will happily vote in a poll, but don't always put their money where their mouth is afterwards. If you at least believe in your product, it won't be so bad.

[ebclr]

OK now the LCD is defined, a nice CPU suggestion to have many very good measurements, and all LCD control

Precision Metrology with Segment LCD MCUs based on Arm® Cortex®-M0+

https://www.nxp.com/docs/en/fact-sheet/KNTSKM3XFS.pdf

[TimNJ]

Hello Dave,
As a newbie in mass production I am wondering why you don't make a poll about some features which seems to "bug" some members (ex. lcd). It looks like you did a research (referring on Newhaven on older post)

It doesn't matter what you do you will never be able to please a majority. Product design by poll or public opinion does not work.

No it doesn't, though more eyes on a problem can often come up with good ideas or spot things you've not considered - just needs suitable filtering
 

Design by committee produces the most horrible products. Besides, it's been shown that people will happily vote in a poll, but don't always put their money where their mouth is afterwards. If you at least believe in your product, it won't be so bad.

It is true that most good designs are spearheaded by a single architect, so I agree that Dave should follow his vision on the product. That said, it is also just as important to remember that just because you think your product is great, doesn't mean everyone else will think the same. This seems to come up on The Amp Hour pretty frequently. Whether it was Bunnie or Gerry Roston or others, they all emphasized the importance of really understanding what the customer (or the world) needs before jumping into product design. That's something I've definitely learned over time, too.

So on that note, as Mike has said, a lot of nonsensical feature requests will come your way, but there also may be some really valuable input buried in that "noise".

[Mr. Scram]

It is true that most good designs are spearheaded by a single architect, so I agree that Dave should follow his vision on the product. That said, it is also just as important to remember that just because you think your product is great, doesn't mean everyone else will think the same. This seems to come up on The Amp Hour pretty frequently. Whether it was Bunnie or Gerry Roston or others, they all emphasized the importance of really understanding what the customer (or the world) needs before jumping into product design. That's something I've definitely learned over time, too.

So on that note, as Mike has said, a lot of nonsensical feature requests will come your way, but there also may be some really valuable input buried in that "noise".

Obviously. I'm not questioning the thread.

[TimNJ]

I just quoted you because I agreed with your sentiment. My reply was directed at Dave and anyone else developing a product (including a reminder to myself!)

[Mr. Scram]

I just quoted you because I agreed with your sentiment. My reply was directed at Dave and anyone else developing a product (including a reminder to myself!)


Sent from my iPhone using Tapatalk

Apologies, I misunderstood.

[aandrew]

Both VFD and OLED aren't as durable as LCD. They tend to wear out or become unobtainable. Longevity is important in products like these, much more than it is in the mobile phone or general consumer markets.

My ancient Fluke 8842A would like to have a word with you about VFD longevity.

At least when it comes to VFDs, they only tend to go bad quickly if they're poor quality or abused.  And I agree with you; longevity is important in bench equipment. I wasn't referring to full colour OLED so much as the more inexpensive, lower density OLEDs used for these kinds of equipment..

[xani]

Well it depends on what device in question do.

Assuming a display have say 20k hours lifetime, that can be ~10 years working in lab, decades working for hobbyist, or a bit over 2 years if run 24/7.

[Mr. Scram]

My ancient Fluke 8842A would like to have a word with you about VFD longevity.

At least when it comes to VFDs, they only tend to go bad quickly if they're poor quality or abused.  And I agree with you; longevity is important in bench equipment. I wasn't referring to full colour OLED so much as the more inexpensive, lower density OLEDs used for these kinds of equipment..

Well, they're known to cause real issues in proper high end gear on a relevant scale. OLED is also known to cause issues, in lower density screens too, even though that might be due to the technology not being very mature.

[EEVblog]

It is true that most good designs are spearheaded by a single architect, so I agree that Dave should follow his vision on the product. That said, it is also just as important to remember that just because you think your product is great, doesn't mean everyone else will think the same. This seems to come up on The Amp Hour pretty frequently. Whether it was Bunnie or Gerry Roston or others, they all emphasized the importance of really understanding what the customer (or the world) needs before jumping into product design.

This product is more niche than mainstream I can assure everyone of that.
Not everyone will want this, but I want it, and often that is were the best product ideas come from.

[TimNJ]

It is true that most good designs are spearheaded by a single architect, so I agree that Dave should follow his vision on the product. That said, it is also just as important to remember that just because you think your product is great, doesn't mean everyone else will think the same. This seems to come up on The Amp Hour pretty frequently. Whether it was Bunnie or Gerry Roston or others, they all emphasized the importance of really understanding what the customer (or the world) needs before jumping into product design.

This product is more niche than mainstream I can assure everyone of that.
Not everyone will want this, but I want it, and often that is were the best product ideas come from.

That's fair. That's usually why I design something, too: Because I want it! And if no one else does, well that's okay.

We'll just have to wait and see.

[ramon]

I'd be really interested in finding out about the process of getting a custom display made - tooling costs, unit costs,MOQ, leadtime, design rules etc.

That's the plan.

Do you also plan to make a custom silicone rubber keypad?

Over the years I have collected a lot of information about companies here in Taiwan that made Rubber Keypads, LCD Displays, E-Ink (it was bought by a Taiwanese company), Silicon molding, Metal stamping, and EMS services. But I have never asked them for any quote, because there is no way I can order 1k to 10k pcs of anything.

Last month I meet with one company that does everything: PCB, PCBA, Plastic Injection, and Packaging. They provide what they call turnkey products. And I was able to see that they were OEM of a known german manufacturer (I saw the case with the logo).

If you are interesed I can sort some information and sent to you. You can ask them directly for quote and I will be glad if you can share some insights with us after your product development.

[RES]

How do colour 7-segment LC displays work?

[mikeselectricstuff]

How do colour 7-segment LC displays work?

fast switching LCD and RGB backlight cycling through colours

[JPortici]

As if my opinion was needed, i am completely in favor of the custom LCD. Incidentally microchip sent me their newest LCD board, the 16F19197LCDDEMO which uses their newest PIC16 available... the board arrived today.
I like the custom lcd because
-looks amazing
-with the right MCU you don't need a controller chip
-so the circuit is extremely simple.. in this case a regulator, the pic, a bunch of passives and the boost converter for the backlight

[kathy]

It is just simple custom lcd panel glass in Maclight display, the icons could be easily changed based on the applications, a basic TN lcd display is okay, if you like a good contrast in negative mode, TN negative or VA TN display mode would be with better contrast, and FSTN mode would be with wide viewing angle.
http://www.szmaclight.com/custom-lcd.html

[EEVblog]

Do you also plan to make a custom silicone rubber keypad?

No, custom membrane.

[BBBbbb]

Do you also plan to make a custom silicone rubber keypad?

No, custom membrane.

Not a big fan of those, in terms of durability and not so easy to (if even possible) to fix... But for keeping the project small (and possible somewhat water resistant) I understand the choice. 

[SiliconWizard]

I personally like custom LCDs. They are very readable and look somewhat "classy" compared to graphic LCDs/OLEDs. No ugly pixelated icons and digits. Of course they are a lot less flexible, but that's also a plus in some cases, as it naturally forces the development to avoid bloated UIs and such, and keep the probability of display bugs much lower.

As to e-paper displays, I don't think that would be a good idea at all. They are terrible regarding refresh rates and the refresh process itself looks ugly. On more recent e-paper displays, you can do partial updates which admittedly are much better looking but that still doesn't look too good when the display is changing fast and constantly. Besides, they actually draw a lot more current than simple LCDs if you refresh them constantly. They are optimal for very infrequent changes. Also, they are pretty expensive if you want a decent resolution (and the small ones with low-res, they look ugly IMO - that's good for price tags but not much else).

I don't know whether Dave plans on adding a backlight or not. Not sure that would add a lot of value. Lab areas are usually well lit, so unless he wanted to target geeks working in their basement with dim lighting.... (a backlight could prove useful on a portable multimeter if anything, but on a power supply...?)

The only thing to consider IMO would be glare (that could be annoying depending on how your lighting is set up) so if an anti-glare coating is possible (either directly on the LCD glass or as an additional front  filter, that would be a plus.