sebm wrote: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?
sebm wrote: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.
sebm wrote: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.
tayken wrote: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.