Robo-Tank Isolated PH Circuit

[Rob F]

I hope the controller hasn't been freezing on you, that's what the I2C buffer solved. But yeah if your RTC has wires attached and plugged into controller board you can move it to the output of the buffer (USB side). Make sure you only connect RTC to 5v if you use the buffer, don't use the power pin on the buffer as it's 12v and will fry the RTC. You can get power from the controller and use SCL/SDA from the buffer output.