Doing some research into how the Pi can be booted and shutdown via an external input, and I want to confirm if my understanding is correct. I initially asked a question a little while ago in the Other Projects forum about this, but then deleted it as my question had evolved some as I was typing it, then when I was done, I found the answer to the new question was readily available on Google.
TL;DR: How would I go about starting and stopping several boards from a single "master" board (Pi or Arduino) using a toggle switch.
The Project: I'm designing a flight simulation cockpit and planning to use multiple R-Pi 4B boards driving 10" touch displays for the instrument panels.
The Problem: I want to be able to turn all of the Pi boards on and off via a single toggle switch (SPST, either a rocker or a classic toggle switch).
From what I've found, the Pi is designed to monitor GPIO3 for powering up and down. When it reads a hi-power signal to GPIO3, it either boots up (if powered down) or shuts down (if powered up), as long as the proper code has been added to config.txt. Is my understanding on that function correct?
I'm very new/inexperienced with programming/electronics, so please understand that what I have in mind may be completely undoable or infeasible. I've dabbled in this stuff a little over the years, but not much.
What I'm thinking about doing here is using either an Arduino or another R-Pi (headless) as a controller board, programmed to watch for a high-power signal on one of it's inputs when the switch is on, and then sending a quick pulse signal out to all of the display boards' GPIO3 pins, thus turning them on. Then, when the switch is flipped off and the controller detects a drop in power on it's input, it sends another pulse out, telling the displays to power down. Would it be better to simply have the controller send out a hi-signal whenever the switch is on, or would a constant hi-power voltage to the GPIO3 pin cause problems/damage to the Pi? I'm still not 100% certain how that part works yet.
TL;DR: How would I go about starting and stopping several boards from a single "master" board (Pi or Arduino) using a toggle switch.
The Project: I'm designing a flight simulation cockpit and planning to use multiple R-Pi 4B boards driving 10" touch displays for the instrument panels.
The Problem: I want to be able to turn all of the Pi boards on and off via a single toggle switch (SPST, either a rocker or a classic toggle switch).
From what I've found, the Pi is designed to monitor GPIO3 for powering up and down. When it reads a hi-power signal to GPIO3, it either boots up (if powered down) or shuts down (if powered up), as long as the proper code has been added to config.txt. Is my understanding on that function correct?
I'm very new/inexperienced with programming/electronics, so please understand that what I have in mind may be completely undoable or infeasible. I've dabbled in this stuff a little over the years, but not much.
What I'm thinking about doing here is using either an Arduino or another R-Pi (headless) as a controller board, programmed to watch for a high-power signal on one of it's inputs when the switch is on, and then sending a quick pulse signal out to all of the display boards' GPIO3 pins, thus turning them on. Then, when the switch is flipped off and the controller detects a drop in power on it's input, it sends another pulse out, telling the displays to power down. Would it be better to simply have the controller send out a hi-signal whenever the switch is on, or would a constant hi-power voltage to the GPIO3 pin cause problems/damage to the Pi? I'm still not 100% certain how that part works yet.
Statistics: Posted by kananesgi — Tue Dec 19, 2023 7:50 pm
