oh, okay - wow - seems like I missed some zips / GitHub resources I needed to download. I think I have them all now, but:
a) Still don’t know if my unit has the right eRPC firmware
b) there’s this…
/home/pi/Arduino/libraries/Seeed_Arduino_mbedtls-2.0.1/src/port/esp_hardware.c:11:10: fatal error: esp_system.h: No such file or directory
Multiple libraries were found for "Adafruit_ZeroDMA.h"
#include <esp_system.h>
^~~~~~~~~~~~~~
Used: /home/pi/.arduino15/packages/Seeeduino/hardware/samd/1.8.1/libraries/Adafruit_ZeroDMA
compilation terminated.
Not used: /home/pi/Arduino/libraries/Adafruit_Zero_DMA_Library
exit status 1
Error compiling for board Seeeduino Wio Terminal.