I’m running a classroom of approximately 15 kits and all of my students updated firmware and ran verifications successfully. This week, two of those robots stopped connecting to their Chromebooks and are not recognized by their Chromebooks nor my Windows PC when they are plugged in via USB. I have confirmed the following:
Other XRP’s connect to the students Chromebook (and my Windows PC) via the same USB cable… so to me, this means the cable is good and their USB ports are working properly.
Batteries are good and tested at 6.4V for the pack. As I understand it, this shouldn’t matter even if the batteries are dead since other XRP’s connect to their respective computers without the pack even plugged in.
I have power-cycled robot and computers frequently.
I have pressed the reset button while connected to the computers, and while disconnected.
I have held the BOOTSEL button while powering on the XRP (without being connected via USB). I would love to be pointed to instructions for doing this properly… I’ve just seen this mentioned in this forum and so I tried it.
I have done the same reboot routine while unpowered by the batteries and using the USB cable to power the board.
I see 2 red LED as I should while I’m powered by the batteries, and just the top red LED when powered over USB. (Same as any of the functional XRP’s).
So, at this point I’m looking for someone to let me know what I’ve done wrong or what I may have overlooked? I’m still hopeful these aren’t bricked. Thanks for your consideration in advance!
Sounds like you have done some good diagnostics. This sounds like there could be bent pin that is shorting and causing the USB problems. We have seen this before. This video has a short section talking about bent pins and how to fix them around the 12min mark.
I’ve removed the RC from the robot chassis and disconnected all peripheral devices from the controller. The pins are straight and nothing is obviously shorted but I am seeing a new behavior. This time while trying the reboot routine (holding BOOTSEL while plugging in USB) I see the “RP1-RP2” drive connect to my Windows computer. It remains open for approximately 2 seconds before disconnecting again. Another couple of seconds later, my computer makes the ‘device connected’ sound but no device is recognized by Windows (not displayed in file explorer and not listed in connected devices). This is now the state every time I connect and disconnect the USB cable. Essentially, Windows knows something is plugged in and removed, but I have no access to the robot controller nor the “RP!-RP2’“ drive as I would expect.
Is this a behavior that is documented somewhere, or am I just lucky? I feel like the RC is physically fine if I could get a clean, updated version of the firmware running… is that an option without access to the ‘RP1-RP2’ drive?
Spoke too soon - I looked at the device manager in Windows again and under UBS controllers I have “Unknown USB Device (Device Descriptor Request Failed)”. Not sure if this helps - just another data point.
I used XRPs in summer camps last summer and in class last fall and had the issue several times with several different boards. I was able to access the “RP1-RP2” drive when holding the BOOTSEL button and then uploaded a “FLASH_NUKE” code to the board (drag and drop the file into the folder). It wipes the board, but they were usable again. The file and documentation are here: Releases · Gadgetoid/pico-universal-flash-nuke · GitHub . Seems to be a known issue with Pico Boards.