Hi @jascha!
The error code 2 means timeout, so it sounds like there is a problem with the communication wiring or for some other reason the host is not responding. How is the esp32 connected to the notecard?
For reference, these are the other error codes for ODFU with esp32:
- 1: unspecified error
- 2: timeout
- 3: image too large
- 4: MD5 checksum error
- 5: invalid parameter
- 6: invalid target
- 7: unsupported MCU
- 8: function not supported on the target
- 9: invalid response/internal error