FAQ

Q: I connected the M-BUS adapter to RX on my board, why can't I receive any data?

A: Development cards with USB interface have the USB-TTL chip connected to RX and TX pin on the ESP. This means that RX cannot be used for the MBUS-TTL adapter. Use a different pin for HAN RX.

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Q: Why is the display voltage for my ESP8266 board lower than actual voltage?

A: Some development boards (f.ex. D1 mini and NodeMCU) has a voltage divider attached at the ADC pin. In the code we use ADC mode ADC_VCC which requires the ADC pin to be unconnected (stated here). Since there is a voltage divider connected, the GND to ADC resistor is interfering with the internal voltage reading. The only way to properly resolve this is to adjust the Vcc multiplier in GPIO settings.