BusPirate crashed computer and now seems broken

[sebm]

Hi,

A couple of weeks ago I bought a Bus Pirate. Anyway, one of the first things I did was checking if the BusPirate worked, I setup the computer (Mac) and run the "self-test" which worked, everything was OK.

After that I started to prepare the rest of my stuff which I completed a few days ago.

Then, when I plugged the BusPirate to the computer again, the computer crashed (it had never crashed) with a gray screen saying that I had to turn it off. I did, then I turned back on, everything works just fine, however the BusPirate does not appear on the USB list.
The power LED is on, but the device does not seem to identify itself as an USB device anymore (it does not appear to be enumerated).
I tried reinstalling the drivers, but that does not seems to work either.
Then I tried with a Ubuntu Live USB drive on a different computer and the device still does not appear to be enumerated (nothing on 'dmesg' nor 'lsusb'). Basically, it seems the BusPirate is dead and/or otherwise malfunctioning.

Do you have any suggestion I can try?
I asked the seller (Watterott electronic GmbH) and they told me that before replacing it, I should ask here for help/support, see if there's something I can do.

Thanks, regards,

Seb

[tayken]

I think there was a short on the board when it crashed. I can only explain such catastrophic damage (crashed pc and broken bp) with that.

I believe it is toast, if linux cannot enumerate it, then I don't know what can. But you can check the components on the board to see if any one of them are damaged. Maybe the main voltage regulator? Also check if there are any shorts on the board. That can help us determine if it was one time problem or some design flaw (I don't think it is but better be safe than sorry).

[ian]

I agree. You can ask Watterott for a replacement. Please tell them I will send a replacement with their next order.

[Sjaak]

You could try pushing on the ft232 chip or the pic24. This would rule out bad solderjoints, however it appears as a short.

[sebm]

Hi,

Here's what I did. I checked the resistance between GND and 5V on the I/O Connector and got around 18KOhm, between GND and 3V3, around 19KOhms.

Since I couldn't find a document about test points and expected voltages/resistance (is there any doc on that?), I'm not sure if that is expected, but it looks pretty low resistance to have between power pins, right?
Since there are LEDs between power and GND I measured the resistance "in both directions".

I also checked the voltage across C7 (VR1 output) and when the Bus Pirate is connected to USB I only get around 3Volts there, VR3 has no output? (no V drop across C9)

BusPirate is v3.6 from April 2012.

I will contact Watterott GmbH again.

However, for future reference, are there some special measures I should take? I don't know, maybe the Bus Pirate does not support hotplug? I was thinking in trying to connect it to a linux box (I found a pandaboard-like board lying around) and login to the box from my Mac (so that I don't have to power cycle the main computer when pluging the Bus Pirate).
Any tips I could use to minimize the likelihood of future "crashes"?

Thanks everybody for your support!

Seb

[tayken]

Here's what I did. I checked the resistance between GND and 5V on the I/O Connector and got around 18KOhm, between GND and 3V3, around 19KOhms.

That is actually normal. There are voltage dividers on 5 V and 3.3 V rails. They use 2 10kOhm resistors each.

I also checked the voltage across C7 (VR1 output) and when the Bus Pirate is connected to USB I only get around 3Volts there, VR3 has no output? (no V drop across C9)

VR1 gets enabled automatically when you plug it in and supplies power to the uC. However VR2 and VR3 have their enable pins connected to the uC, so they get turned on once they get the command. So that is normal. Can you see any physical damage on those? VR1 should give about 3.3 V so I'm not sure if a measurement of 3 V is a concern. For a possible reason, read along.

However, for future reference, are there some special measures I should take? I don't know, maybe the Bus Pirate does not support hotplug? I was thinking in trying to connect it to a linux box (I found a pandaboard-like board lying around) and login to the box from my Mac (so that I don't have to power cycle the main computer when pluging the Bus Pirate).
Any tips I could use to minimize the likelihood of future "crashes"?

BP has no problems with hotplug, it is the nature of USB. :) Now that I know it is a BPv3.6 and it not enumerating, your FTDI IC is toast. This may be the reason that you see 3 V on VR1 output. Also there is a slight chance that the uC is still alive. Short PGC and PGD pins as you are updating the firmware, if the MODE LED lights up, the uC is still alive. For future I would say just watch around where you are working. Water, tiny solder balls, cut component legs all cause problems when an active electronic circuit is placed on top of them.

[sebm]

Here's what I did. I checked the resistance between GND and 5V on the I/O Connector and got around 18KOhm, between GND and 3V3, around 19KOhms.

That is actually normal. There are voltage dividers on 5 V and 3.3 V rails. They use 2 10kOhm resistors each.

Oh, I see them now, I missed them reading the schematic. Sorry for the misleading test then.

I think a document detailing the test pins would be a nice addition to the website, it would make measurements and troubleshooting by less than expert people somewhat easier. What do you guys think?

I also checked the voltage across C7 (VR1 output) and when the Bus Pirate is connected to USB I only get around 3Volts there, VR3 has no output? (no V drop across C9)

VR1 gets enabled automatically when you plug it in and supplies power to the uC. However VR2 and VR3 have their enable pins connected to the uC, so they get turned on once they get the command. So that is normal. Can you see any physical damage on those? VR1 should give about 3.3 V so I'm not sure if a measurement of 3 V is a concern. For a possible reason, read along.

Ok, that would explain the zero at VR3 considering I cannot send any commands.

However, for future reference, are there some special measures I should take? I don't know, maybe the Bus Pirate does not support hotplug? I was thinking in trying to connect it to a linux box (I found a pandaboard-like board lying around) and login to the box from my Mac (so that I don't have to power cycle the main computer when pluging the Bus Pirate).
Any tips I could use to minimize the likelihood of future "crashes"?

BP has no problems with hotplug, it is the nature of USB. :)

by the way, when looking for info on the OSX crash with the bus pirate on the internet, I found that some people were saying that one should not unplug it when a "screen" session is active, does somebody knows if that is still the case and if it is only something to watch out only with "screen" and/or with OSX-only? As you know, "screen" is also available for Linux.

Now that I know it is a BPv3.6 and it not enumerating, your FTDI IC is toast. This may be the reason that you see 3 V on VR1 output. Also there is a slight chance that the uC is still alive. Short PGC and PGD pins as you are updating the firmware, if the MODE LED lights up, the uC is still alive.

I'm not sure I understood what you meant. I don't have a PIC programmer, so I'm not sure I could do a firmware update, or could I?

Anyway, I think I will just try to get a replacement for the device, because I would like to first move on with the project I needed this for, then I will have some time to experiment with firmware updates, etc.

For future I would say just watch around where you are working. Water, tiny solder balls, cut component legs all cause problems when an active electronic circuit is placed on top of them.

I'm positive that there was nothing like that on the table, I was not in the lab when this happened, I had the Bus Pirate next to my computer so it was on a regular desktop, wooden table.

Anyway, thank you again for all your support.

Seb

[andersm]

by the way, when looking for info on the OSX crash with the bus pirate on the internet, I found that some people were saying that one should not unplug it when a "screen" session is active, does somebody knows if that is still the case and if it is only something to watch out only with "screen" and/or with OSX-only?

That would suggest a bug in FTDI's drivers. An application can't cause a kernel crash.

[ian]

one should not unplug it when a "screen" session is active, does somebody knows if that is still the case and if it is only something to watch out only with "screen" and/or with OSX-only? As you know, "screen" is also available for Linux.

That sounds like an improper handling of error condition in the driver, but nether PC nor Mac like it when you (re)plug devices with the port already open.