Bricked Xiao ESP32-C3 can't flash new code or bootloader

Products & Technology XIAO
#1

I have a Xiao ESP32-C3 that exhibits all of the same symptoms as this case here:

I’ve been updating code for my board over the last few days, and finally messed up by calling rmt_driver_install() twice in my setup function. The ESP32-C3 is now stuck in an infinite boot, abort (crash), and reboot loop. I can see the reboot cycle happening over the serial monitor. When I try to upload code, I always encounter the dreaded
A serial exception error occurred: Write timeout
problem. I’ve tried:

1.) Making sure the ESP32-C3 is entering bootloader mode by holding down the boot button while powering on the device. I know I’m doing it right because this has solved my boot issues in the past.
A serial exception error occurred: Write timeout
If I don’t hold down the boot button, then I get
A fatal error occurred: No serial data received.

2.) Reflashing the bootloader. The write timeout prevents this from happening as well.

> ERROR:Write timeout
> WARNING:Sync fail...

3.) Forcing GPIO2 low. Holding GPIO2 at ground from power-up to code upload doesn’t change anything.
4.) Forcing GPIO2 high. Holding GPIO2 at 3.3V from power-up to code upload doesn’t change anything.

Nothing is connected to GPIO2.

5.) Restarting PC and updating the drivers for ‘USB JTAG/serial debug unit’ in device manager.

Is it bricked for good?

#2

The following steps may be helpful

  1. Is “USB JTAG/serial debug unit” listed under “Universal Serial Bus Devices” in the Device Manager?
    Note: not “Ports (COM & LPT)”.
  2. If not, this method does not work.
  3. If so, right click “USB JTAG/serial debug unit” and “Update Driver”
  4. select “Browse my computer for drivers”
  5. select “Let me pick from a list of available drivers on my computer”
  6. select “USB Serial Device” and click “Next”

If you are lucky, it will be restored.

2 Likes
#3

Incredible. I thought there was no way it was a driver problem, because I had flashed code dozens of times just minutes before the board went AWOL. Also, I had done the exact steps you described less than 24 hours ago when troubleshooting a similar problem.

But, I did it again right now, and successfully recovered the device. You’re a lifesaver in this forum. Thank you!

1 Like
#4

awesome… you always find the answer in the last place you look…lol

1 Like