Unable to reset/update RTK Express

Hi, I was recently trying to configure the DATA port Rx/Tx of my RTK Express unit. I had a serial connection open between the UBLOX CONFIG port and u-center 22.07 on my Windows machine. I believe I made a mistake when writing the settings to the device’s flash memory because after I disconnected and powered off the unit, it fails to turn on. If I press and hold the power button, the display flashes with the startup message for a fraction of a second before disappearing and the COM port similarly flashes on my computer screen.

I figured I would try to reset the ESP32 and replace the firmware, but I’m not sure how to do that (using RTK_u-blox_Update_GUI.exe or otherwise) because the device does not power on (so the COM port does not get detected and communication can’t occur). Could someone please help me find a way forward?

Please remove all items and external devices from your ports: DATA, USB, etc. Once everything has been removed, re-connect a single USB cable to the CONFIG UBLOX and your computer (this is to provide power). Try to power on the unit by holding the power button until the display shows ‘SparkFun RTK Express’. Does it show ‘RTK Express’ or ‘RTK Surveyor’? If it shows RTK Surveyor then the unit has a hardware issue that will need repair.

The unit flashes ‘SparkFun RTK Express v1.7’, exactly the same as my other functioning units.

Ok, you should be able to reset the device to factory defaults by modifying the settings file (https://docs.sparkfun.com/SparkFun_RTK_ … tory-reset). Because your firmware version is so old, I’m not completely sure this will work but it’s worth a shot.

Another option: Updating the ESP32 firmware via the GUI should work. We sometimes have to power on the device and quickly hit the Upload Firmware button before the device turns off. You cannot brick a device.

If all else fails, we’re happy to have a look and repair/reprogram the device as needed. https://www.sparkfun.com/returns will get you an RMA for a return.

Thank you for the suggestions - between the two options, I’m sure something would have been effective. Oddly enough, after a few days with the device off, it powered on like normal and worked properly. I wonder if some layer of BBR taking over or being bypassed is responsible.