Ascii or hex

[antonhagg]

Since you have investigated this a bit already, and The know how doc is in german, is it possible to comunicate with the emh1 with hex commands or is it just ascii?

[raibisch]

the communication is with hex-command decoded in an serial ASCII-ascii

e.g.
const char* ABL_TX_POLL_MESSAGE = ":0103002E0005C9";

for details look at:
https://github.com/raibisch/ESP32_ABL/blob/main/doc/knowhow.txt
(...and use google translate ;-)