Strange power problem

Using Arduino General Electronics
14

TomGeorge:
Hi,
Please answer post #8.

Thanks.. Tom.. :slight_smile:

That diagram is basically it, stick 2 nanos and a mega onto the 9v, connect their I2c's together and that's it.
The regulator is an LM7809 and a 0.33uF on the input and a 0.1uF on the 9v side