Description: -

I had interfaced Selec EM2M meter with R-pi to collect data over MODBUS and use the info for IOT purpose. The meter is connected to my house meter for collecting realtime info about the power consumption in my home.

Following picture shows the initial test done with a cheaper version of USB-RS485 converter. Though there was no issue with functionality, the converter board was without any plastic cover, making the board risky.

I ordered a different version of USB-RS485, which is covered in plastic enlosure and connected 2 meters (for a network).

Below is a video of demonstration

Below is a presenation with explanation of the RS485 physical layer and explanation of protocol used for EM2M modem.

Below code is to perform CRC check needed for MODBUS communication. This file should be saved with name "MODBUS_CRC16.py".

Below code is to perform serial communication from R-pi with Selec modem via MODBUS. This file also need the "MODBUS_CRC16.py" code, which is the above code.

Change COM port number to the proper one as on your computer