Hi again, thanks for answering. Sry for not including the circuit from the start. I added it now, as you can see. Unfortunately the adresses between 0x2C - 0x2F don't work. Maybe the IC is faulty?
if (datastring[0] == "M"[0]) {
Yea, i thought that this is not a very elegant solution. I thought that i had to compare a char to a char and that
if (datastring[0] == 'M') {
wouldn't work because here i compare a char to a string (i think) and i had problems with that in the past.
This code part
if ((datastring[1] + datastring[2]) == ("on"[0] + "on"[1])) {
works so far, as it does what is in the brackets after the if statemant. But you are right that the handling with the string class in the arduino is stupid from my side. We built it up like this, because we needed something workin pretty quick. I will mntry to rewrite the arduino code, and the python side accordingly to communicate over byte class instead of string class.