Thanks so much. I hadn't even considered that the HDMI ports would be doing that. I just saw that it worked when testing with monitors, and didn't think about the fact that the circuit made no sense without a shared ground *somewhere*.
I connected the two Pis' grounds and the HIGHs persist with the monitors disconnected on either and both setups.
In this project, the two Pis won't be able to be grounded together, so I am at a bit of an impasse here. This may not be the forum for this, but EE was always my weakest discipline, so I'll ask stupid questions.
I *think* I've tested and confirmed that if I use an external battery, this setup works towards my goal:
-3.3V battery, connected to the GND of Pi #1
-3.3V line connects to a wire connected to Pi #2's GND.
Do you or does anyone know if I can use a transistor, or some other component, to tell when there's a current along the wire to the GND? And use that to send the HIGH signal to Pi #2's GPIO pin?
I connected the two Pis' grounds and the HIGHs persist with the monitors disconnected on either and both setups.
In this project, the two Pis won't be able to be grounded together, so I am at a bit of an impasse here. This may not be the forum for this, but EE was always my weakest discipline, so I'll ask stupid questions.
I *think* I've tested and confirmed that if I use an external battery, this setup works towards my goal:
-3.3V battery, connected to the GND of Pi #1
-3.3V line connects to a wire connected to Pi #2's GND.
Do you or does anyone know if I can use a transistor, or some other component, to tell when there's a current along the wire to the GND? And use that to send the HIGH signal to Pi #2's GPIO pin?
Statistics: Posted by GogglesGreek — Tue Jun 11, 2024 11:56 pm