Hi everyone, I am trying to use I2C communication between arduino UNO and OpenCM. Actually the problem is the OpenCM is already connected with OpenCM485 exp board which communicates through (pins: 24, 25). In the manual (OpenCM),the SDA_2 SCL_2 pins are mentioned clearly. However, I couldn't find the SDA_1 SCL_1 pins. thanks in advance.