May I ask about the voltage drop across a diode?

Hi, @topfastpcb
Welcome to the forum.

What micro-controller are you using?

Can you please post a copy of your circuit, a picture of a hand drawn circuit in jpg, png?
Hand drawn and photographed is perfectly acceptable.
Please include ALL hardware, power supplies, component names and pin labels.

Thanks.. Tom.. :grinning: :+1: :coffee: :australia: