Arduino Nano V3 only runs sketch correctly after hitting reset or starting serial monitor

Projects Programming
40

Hi,
I2C... SDI and SDA ????
I2C SCL SDA... Have you got 4k7 pullup resistors on the SCL and SDA lines.

Pins numbers on your circuit diagram will also help.
Where and what is your supply when the USB is unplugged?
Please include...

Tom... :smiley: :+1: :coffee: :australia: