It very much depends on what knowledge the OP has and whether there is a possibly tight deadline for the project.
A simple, quick setup would be three Pi4, each equipped with a HDMI monitor. I assume that the monitors are arranged within hdmi range. A DC 5V 75W power supply unit for the three Pi.
A button connected to one of the RPi (controller). If cable length > 30cm then twisted wire, extra pullup, RC filter necessary. This controller sends start signals via UART (controller out, both other RPI UART in) to the other two RPi (place a 1k resistor in series for each UART input for failsafe operation). UART just in case there will be an evolution of this project and multiple video will be used.
You could alternatively use network connection, but then an ethernet switch is needed on the bill of material. Aside from extra cost this would be an entry point for remote maintenance and monitoring. And allow for larger distances between the RPi/monitor.
Mount the three RPi on a board close together. Adjust so that the network, USB connections are accessible for maintenance. Mount the power supply on the board. Add strain reliefs for the cables. Covers are necessary for dust and safety. Heat generation is low, but extra air circulation may be necessary though.
Write a python program for controller (button in, send UART command, activate video) and and the other RPi (uart in, activate video). Autostart with systemd.
Configure the RPi in “read only mode”.
Provide an extra RPi as a development machine/spare part for your desk. Buy extra SD cards in case of replacement needs. Archive the OS, setup files, video on an extra computer (no backup, no mercy). Document the setup and operating instructions.
An even quicker solution is to look for a hackspace community in the neighborhood and involve the nerds.
A simple, quick setup would be three Pi4, each equipped with a HDMI monitor. I assume that the monitors are arranged within hdmi range. A DC 5V 75W power supply unit for the three Pi.
A button connected to one of the RPi (controller). If cable length > 30cm then twisted wire, extra pullup, RC filter necessary. This controller sends start signals via UART (controller out, both other RPI UART in) to the other two RPi (place a 1k resistor in series for each UART input for failsafe operation). UART just in case there will be an evolution of this project and multiple video will be used.
You could alternatively use network connection, but then an ethernet switch is needed on the bill of material. Aside from extra cost this would be an entry point for remote maintenance and monitoring. And allow for larger distances between the RPi/monitor.
Mount the three RPi on a board close together. Adjust so that the network, USB connections are accessible for maintenance. Mount the power supply on the board. Add strain reliefs for the cables. Covers are necessary for dust and safety. Heat generation is low, but extra air circulation may be necessary though.
Write a python program for controller (button in, send UART command, activate video) and and the other RPi (uart in, activate video). Autostart with systemd.
Configure the RPi in “read only mode”.
Provide an extra RPi as a development machine/spare part for your desk. Buy extra SD cards in case of replacement needs. Archive the OS, setup files, video on an extra computer (no backup, no mercy). Document the setup and operating instructions.
An even quicker solution is to look for a hackspace community in the neighborhood and involve the nerds.
Statistics: Posted by ghp — Sat Jul 12, 2025 9:50 am