EEVblog #357 - USB Supply Power-up Testing

[firewalker]

About VIPD:PID. It seems there is a way to buy a combination for 10 USD.

http://fourwalledcubicle.com/blog/2010/03/obtaining-a-vid-and-pid/ (also read through the comments)

Alexander.

[opablo]

This power supply style is such a great idea… I’m really happy that you ended up with an lcd for the display after exploring all the other possibilities. Maybe the other were cheaper but lcd is the best way to go… Do you have any idea about how much are you going to price it ? Because I’m already interested in buying you one. Do you ship internationally ? (Argentina) I can even buy a pre-sale if that helps you fund the design efforts.

[JoannaK]

Ah, i know why there is no stock of the FTDI X series chips, as I got caught out myself too in a design.

FTDI found a silicon bug which caused the chip to lock up unexpectedly (there is workaround by using a keep-awake pin) and pulled all the devices off the shelf. I bought a heap from Digikey and got an email, and they offered to return all the parts at their cost and to they were to send me replacements also at their cost.

The details are here:
http://www.ftdichip.com/Support/Documents/TechnicalNotes/TN_139_FT230X%20Errata%20Technical%20Note.pdf

Have to say that FTDI is a strange company, pulling product back entirely for just a small issue like that. I have seen a lot worse bugs on chips that been kept on selling trough distiributors.

[T4P]

That show they have pride in their parts - unlike Microchip whom chips come with a myriad of silicon bugs

[Rutger]

Oh and while were are at it, get ride of most buttons and display and only allow the interface via Bluetooth with an app for iphones & android.

That is just wank. You have never worked on a bench, doing some real work, did you? Then you would know you need knobs, real knobs, not that stupid fondling junk to wank about.

Just because you think a UI is too hard too write? All you need is a on/off button. You set the voltage / current via the app, how much more tweaking do you need? Touch screen phones and apps are called progress, I bet you are still using a 'non' smart phone.  Why re-invent the wheel for every unit, your phone has all the display you will every need, and it can log any data send by your equipment.  This is not wank stuff, it is called progress.

[Rerouter]

i hold nothing against there being the capability of phone control via bluetooth, but he is dead right in that a power supply should be usable on its own 2 feet in this case, your product starts to look like crap when you cannot use test gear when your phone is dead or missing, or is simply not compatible with the software

[tom66]

This power supply style is such a great idea… I’m really happy that you ended up with an lcd for the display after exploring all the other possibilities. Maybe the other were cheaper but lcd is the best way to go… Do you have any idea about how much are you going to price it ? Because I’m already interested in buying you one. Do you ship internationally ? (Argentina) I can even buy a pre-sale if that helps you fund the design efforts.

I hope this is a joke. I would hate to use a power supply over bluetooth or some unreliable wireless connection. Oops, bluetooth lost - now my dev board fries as it gets 10V instead of 3.3V and I can't turn it off because there's no on/off switch, voltage dial or otherwise. Or, oops, bluetooth lost, how much current did it just draw then, oh, you'll never know.

[gxti]

Dangit, my troll meter is broken again. I was sure the first post was satire but now I'm just confused.

[T4P]

Just because you think a UI is too hard too write? All you need is a on/off button. You set the voltage / current via the app, how much more tweaking do you need? Touch screen phones and apps are called progress, I bet you are still using a 'non' smart phone.  Why re-invent the wheel for every unit, your phone has all the display you will every need, and it can log any data send by your equipment.  This is not wank stuff, it is called progress.

That's not progress, that's going backwards.

[opablo]

This power supply style is such a great idea… I’m really happy that you ended up with an lcd for the display after exploring all the other possibilities. Maybe the other were cheaper but lcd is the best way to go… Do you have any idea about how much are you going to price it ? Because I’m already interested in buying you one. Do you ship internationally ? (Argentina) I can even buy a pre-sale if that helps you fund the design efforts.

I hope this is a joke. I would hate to use a power supply over bluetooth or some unreliable wireless connection. Oops, bluetooth lost - now my dev board fries as it gets 10V instead of 3.3V and I can't turn it off because there's no on/off switch, voltage dial or otherwise. Or, oops, bluetooth lost, how much current did it just draw then, oh, you'll never know.

I think I talked at the wrong time  (in the middle of the bluetooth control discussion)
I was talking to Dave in a general way and not about that bluetooth-control discussion.
About that; I'm in favor of considering such a nice feature as that: a nice -extra- feature.
My ideal interface would be an lcd able to show ongoing V and I at the same time and 2 buttons for "set v" and "set I" and a digital encoder knob.
When I talked to Dave about "exploring other possibilities" I was talking about the binary encoded leds that he talked about once.

This note is just clarification... sorry about it being this long. 

[lafontas]

Hey Dave, just joined the forums. You gave this product the review it deserved. I've been getting real enjoyment out of electronics since the 1960's when I put together some wire, tinfoil, batteries and a mechanical bell to make my first burglar alarm

What frustrates me is that while arduinos, raspberries, et all have really made electronics accessible and affordable for total amateurs like me, decent bench scopes and such are still too costly.

Hopefully we will see decent and affordable pocket oscilloscopes along with other tools in the near future.

I enjoy your work, cheers.

[EricBNYC]

Dave.

TWO Fluke 87v meters Dave?  That's just showing off . . . 

[nitro2k01]

TWO Fluke 87v meters Dave?  That's just showing off . . . 

Nah, just wait until he brings out four of them. Two for the input and two for the output.

[NiHaoMike]

I would recommend against the infamous PL2303, at least some of them have strange bugs. (At work, I have seen several devices that don't work with a PL2303 adapter. One actually managed to brick a thermal controller unit somehow. But FTDI adapters just work!)

As for the USB IDs (if not using a FTDI), what's wrong with just making one up? Is it even possible to claim copyright on just 4 bytes of data?

[gxti]

If you don't play by the USB-IF's rules then they won't let you use their trademarks -- in particular the USB logo -- to advertise your product or its capabilities. There may also be patents (especially for USB 3) that are licensed on the condition that you pay all the appropriate fees. This includes not only the fee to acquire a vendor ID, but also per-unit fees that are usually baked into the price of the transceiver chips you buy. Certainly nobody is going to stop you from using arbitrary IDs for your own amusement, but once you start selling it to others you're at risk of legal action.

[EEVblog]

TWO Fluke 87v meters Dave?  That's just showing off . . . 

Nah, just wait until he brings out four of them. Two for the input and two for the output.

I only have two!

Dave.

[Monkeh]

I would recommend against the infamous PL2303, at least some of them have strange bugs. (At work, I have seen several devices that don't work with a PL2303 adapter. One actually managed to brick a thermal controller unit somehow. But FTDI adapters just work!)

PL2303s are cheap, and that's about all they have going for them. There are a lot of knockoffs, too.

FTDI stuff is pricy, but it works well and is very flexible.