EEVblog #644 - How To Design Front Panels On Extruded Enclosures - µSupply Part

[EEVblog]

Dave shows some techniques on how to build and mount usable PCB based front panels user interfaces with LCD displays and push buttons and capacitive touch buttons onto small cheap extruded aluminium enclosures.
In particular for the µSupply project. This is Part 14 of that series.
The uCalc project gets another look in, and does the Sharp Memory dot matrix LCD.

[Legit-Design]

The uCalc project gets another look in, and does the Sharp Memory dot matrix LCD.

It's this one?
http://www.sharpmemorylcd.com/1-17-inch-memory-lcd.html LS012B7DD01

Size   1.17 inch
Pixel Format   184 × 38
Outline Dimension   35.1 × 11.0 × 0.741 mm

If it is, then where to get some? Can't find it on octopart/findchip/ebay...

[DJohn]

It's this one?
http://www.sharpmemorylcd.com/1-17-inch-memory-lcd.html LS012B7DD01

Mouser have the 128x128 and 96x96 memory displays.  They claim the 184x38 is discontinued, which is a shame - it'd be perfect for calculators.  Small, easy to drive, and very low power.

[EEVblog]

Mouser have the 128x128 and 96x96 memory displays.  They claim the 184x38 is discontinued, which is a shame - it'd be perfect for calculators.  Small, easy to drive, and very low power.

That was the idea, I was going to use it in my µWatch II.
I got it as samples direct from Sharp.
I noticed it was discontinued at the time, but I recall they mentioned that it's not actually discontinued. Was some time ago though.

[EEVblog]

If you renamed it to take "µ" out of the name would you still feel the urge to make it so small?

Yes, I want a small unit.

Didn't you leave off with some obscure problem with one of the chips you planned to use? I am rewatching µSupply TOS (the original series) but haven't got there yet.

Yep, the LT3080 had some issues so I dropped it. But I never got around to shooting that episode investing it.

[JonnyBoats]

Dave,

Would you please provide a link where one can order these cases from China?

Thanks.

[nathanpc]

The µSupply is back!

Do you still have the links for anyone that might be interested in buying any of the cases (specially that "TO-220 compatible" black annodized one?) you showed for a next project?

I never heard of those amazing colored screws, I'm definitely going to use them on my next project. Thanks for the tip Dave!

[robrenz]

How do you type "µ"? I had to cut/paste it from the thread title.

hold Alt key and type 0181

[David_AVD]

I dunno about using a board mounted heatsink that radiates into such a small enclosure cavity.  Surely that would just heat soak the insides and then provide poor transfer to the outside?

[nathanpc]

I dunno about using a board mounted heatsink that radiates into such a small enclosure cavity.  Surely that would just heat soak the insides and then provide poor transfer to the outside?

Drilling some holes on the top and bottom (maybe add some standoffs) and let convection take care of it? If you want to be sure that it'll be cool all the time maybe add one of those super tiny fans on the back.

[bktemp]

Nice to hear that the uSuppy project is still alive.

But there are some points I do not agree with Dave:
When the lcd module is only mounted using its connector it is not as stiff as when screwed at all 4 edges. The lcd will bend a litte bit at the top, especially when there is no additional protection window in front of the display, so it can be touched and pressed in easily. This looks cheap and allows dirt to get into the case. The other lcd module from newhaved displays with chip on glass will bend even more and eventually break the backlight connections when the unit is dropped.
Using a 2 board construction is better in my opinion: The outer board mainly acts as the front panel and only contains some capacitive keys or some reverse mounted leds. The inner board contains the lcd and the buttons. The buttons have a knop or a longer shaft that goes through the front pcb. The lcd is sandwiched between the two pcbs, giving a very rigid construction.

Is there any benefit of using the sharp memory lcds? The ultra low current consumption is not really neccessary compared to the total consumption of all other parts in the circuit. The last time I have seen those lcds, their contrast was not great and strongly dependent on the viewing and light entrance angle. I would go for a standard 2x16, 1x16 or 2x8 or similar sized graphic lcd. The benefit of a standard lcd is the price and the availability of displays with backlight. A backlit positive mode lcd is readable under all lighting conditions.

[nathanpc]

When the lcd module is only mounted using its connector it is not as stiff as when screwed at all 4 edges. The lcd will bend a litte bit at the top, especially when there is no additional protection window in front of the display, so it can be touched and pressed in easily. This looks cheap and allows dirt to get into the case. The other lcd module from newhaved displays with chip on glass will bend even more and eventually break the backlight connections when the unit is dropped.
Using a 2 board construction is better in my opinion: The outer board mainly acts as the front panel and only contains some capacitive keys or some reverse mounted leds. The inner board contains the lcd and the buttons. The buttons have a knop or a longer shaft that goes through the front pcb. The lcd is sandwiched between the two pcbs, giving a very rigid construction.

A right-angle PCB mounted in some cutoffs on the main board with some headers for data and power would be even better/easier in my opinion.

[AmirTheGreat]

Dave,

Would you please provide a link where one can order these cases from China?

Thanks.

not the exact link, but this might be a good start http://www.alibaba.com/wholesale/search?SearchText=enclosure+aluminum&pid=1878732840

[nitro2k01]

How do you type "µ"? I had to cut/paste it from the thread title.

hold Alt key and type 0181

On Windows, yep. Also, start, run, charmap. Now you can select the µ sign and a bunch of other more or less useful signs. On some national keyboard layouts that are using right alt as alt gr, you can press alt gr-M or ctrl+alt-M to type the character. In OSX, I believe you can press alt+M with any keyboard layout to produce a µ.

[nixfu]

 
I have one of those EXACT cases I purchased off of Ebay for a project I am building right now, and they really are quite nice for the price.   I have used the plastic cases from Hammond etc before, but ONE THING that has always bugged me in making my projects look nice is LCD mounting. 

What is the best way for a hobbyist to mount a typical 16x2 LCD panel or something to it looks professional, the backlight does not leak out the edges etc.  Whenever I have just cut a hole, and stuck the LCD behind the hole it really does not look that good. 

Should I be making glass/plexi front screens and attaching those to the front of the panel and having the LCD behind it?

Anyone else have a good LCD mounting solution you use for making your homebrew cases look nice and professionally made??

[Asim]

Dave, what are you replacing the LT3080 with ? I remember you saying classic LM317 on the thread that discovered the problem.  I am curious or do we need to wait for a video to know   

[Pedram]

i think there is enough room for using two thumbwheel pots
like this one :

[EEVblog]

How do you type "µ"? I had to cut/paste it from the thread title.

hold Alt key and type 0181

I use Alt 230 for µ

[free_electron]

Nobody spotted that throughout the entire video dave is holding the lcd upside down ?
So it wouldn't work... You would have to mount the board on the top and the buttons would sit above the lcd ...

[rahandford]

Dave,

Would you please provide a link where one can order these cases from China?

Thanks.

Was just about to ask the same thing

[PA0PBZ]

Mounting a TO220 on the bottom and then having to slide in your pcb, how are you going to wiggle the leads trough the pcb holes? 



(Strange, I could not post it without changing the subject, it told me it had to be 80 chars or less - in Dutch)

[free_electron]

Mounting a TO220 on the bottom and then having to slide in your pcb, how are you going to wiggle the leads trough the pcb holes? 



(Strange, I could not post it without changing the subject, it told me it had to be 80 chars or less - in Dutch)

just make a hole in the PCB where the screw needs to go. solder to220 in , slide board in. stick screw through hole. simple .. no ?

or do a compression mount. use a piece of bergquist silastomer between board and to220. that has enough compression to keep the to220 nicely pressed against the case. we use that all the time in harddisks.

[PA0PBZ]

Mounting a TO220 on the bottom and then having to slide in your pcb, how are you going to wiggle the leads trough the pcb holes? 

just make a hole in the PCB where the screw needs to go. solder to220 in , slide board in. stick screw through hole. simple .. no ?

or do a compression mount. use a piece of bergquist silastomer between board and to220. that has enough compression to keep the to220 nicely pressed against the case. we use that all the time in harddisks.

I agree, but that was not what Dave was talking about, with the screw on the bottom outside and all.

[Monkeh]

Mounting a TO220 on the bottom and then having to slide in your pcb, how are you going to wiggle the leads trough the pcb holes? 

just make a hole in the PCB where the screw needs to go. solder to220 in , slide board in. stick screw through hole. simple .. no ?

or do a compression mount. use a piece of bergquist silastomer between board and to220. that has enough compression to keep the to220 nicely pressed against the case. we use that all the time in harddisks.

I agree, but that was not what Dave was talking about, with the screw on the bottom outside and all.

You put the nut on the outside and the screw on the inside.

Alternatively, you make a hole big enough for a nut driver.

[Bored@Work]

Should I be making glass/plexi front screens and attaching those to the front of the panel and having the LCD behind it?

Anyone else have a good LCD mounting solution you use for making your homebrew cases look nice and professionally made??

A typical construction is to have a front PCB, holding all front parts, like LCD, switches, sockets, etc. and then have the actual frond panel in front of it, in a kind of sandwich construction. In between some plexiglas inset/bezel for the display. For hobby stuff it is instead common to mount all switches, displays, etc. directly on the front panel.

If you have the manual skills, tools, etc. you can make your own front panel and LCD bezel. For the rest of us there are http://www.digikey.com/product-search/en/optoelectronics/bezels/