I am using a Votronic SR 300 Duo Digital with serial no. 13v20.0121 which is not capable of connecting the Votronic bluetooth devices (supported starting with serial no. 14Vxx.xxxxx):
In my RV it is connected to a Votronic Solar Computer S 1250 (again not capable of the bluetooth stuff which started with serial no. 15V40.xxxxx):
So I tried connecting a logic analyzer and found some flanks with the smaller ones beeing 980µs apart which seemed to be a bit length. I added a UART analyzer with 1020baud (1 / 0.000980 = 1020) and now I was able to see some bytes without any timing errors:
To verify the voltage I attached a digital storage oscilloscope and found a pretty solid 5V level output (1 y-unit = 1V):
After selling the above mentioned SR 300 Duo Digital along with the RV, I bought a Votronic MPP 430 Duo Digital for my new RV. The protocol is similar but contains e.g. the battery voltage as well which can come in quire handy.
Simple paltform IO project for esp32 using hardware serial: basic-platformIO/src/main.cpp.
No device at hand? Try: arduinoNoDevice.ino.
The most relevant pins would be :
- Serial Data
- Solar/Main Battery +
- GND
