Hi Stuart, thanks for the instructions. That was the way i was doing it, i’d also tried with various pullup resistors but non seemed to work. I was testing with a nodemcu 0.9 board so i switched to a Wemos D1 board as it has built in pullups and received the same, i was looking through your code and after modifying the line Wire.setClockStretchLimit(1000); to be Wire.setClockStretchLimit(1500); but also move it to after the Wire.begin(4, 5); //SDA/SCL statement I was able to get some correct values and have two units hooked up as shown in my pic earlier. Really appreciate your help. I have a small youtube channel and wondered if you minded putting up a bit of content around your design and modifying it for grafana output also.