I have an Arduino Uno connected to a computer via USB cable - no other power cable. I’ve connected an RF receiver and an RF transmitter. Both work fine and I amble send and receive stuff.
Now I’ve connected an LCD shield. Now the transmitter does not work (receiver works). When I remove 5v & ground from the LCD shield (ie LCD shield loses power) all works again.
Just by itself the LCD shield works fine.
Am I looking at a power problem or shield causing interference or both?
I have an Orange Pi nearby and I could supply 5v & ground fom its gpio pins. Is this ok? (I don’t want to fry my boards) Are there some caveats in this setup?
What if I add a 9v battery connection to Arduinos power connnction (ie. can I have both USB and power at the same time).