I managed to use the HK Flash bridge to flash the gpio test

Question

I managed to use the HK Flash bridge to flash the gpio test hex to the caravel without the Hat connected to the Nucleo Now I am stuck in weird situation because as soon as the board is powered on the Caravel reads from flash and starts executing the code Because of this I am no longer able to flash any other code or use the caravel hkdebug interface IS there a specific power on sequence that has to be followed in order to access the hk spi again If so does it involve controlling the reset pin as without the nucleo the only way to reset is via the push button

Tim Edwards · Answer

Yes It s not particularly convenient but if you want to flash a new program e g using `caravel hkflash py` then do the following 1 Hold down the reset button 2 Power cycle the device by unplugging replugging the USB do not let go of the reset button 3 Run `caravel hkflash py` Once the program is communicating with Caravel it will use an internal reset via the SPI to hold the processor in reset so once you see text coming back from the chip you can finally let go of the reset button

Tim Edwards · Answer

Likewise you can use `caravel hkdebug py` after doing the same power cycle + holding down the reset button Once you get the debug menu use it to put the processor into reset then you can let go of the reset button

Tim Edwards · Answer

It s actually a bit more convenient using the Nucleo because you can directly control both power and reset from the Nucleo board using micropython You can also set up the serial communication that s what s used with `make flash` in the `nucleo ` directory for use with the Nucleo board it s just the `caravel hkflash py` code slightly rewritten to set it up on the Nucleo I have been able to read and write registers using the housekeeping SPI by making calls directly from micropython using `mpremote` on the Nucleo