Startup/Shutdown control of multiple Pis

[drohl]

I've assembled a series of interactive pieces for a soon-to-open museum exhibit. Currently, I have 5 non-networked Pis, each set up to boot to the command line, automatically login as user pi and start a script (different script on all 5 Pis).

For the sanity of the exhibits department and longevity of input/output devices, I'm trying to come up with an easy way to turn all the Pis on and off. On is easy - when they receive power, the exhibit is fully operational within a minute or so. But I want a way to shut them all down. Would the best practice be

• to wire a button to a GPIO pin on each, and set up a script to run a safe shutdown when pressed?
• to network the Pis, and have one GUI/command prompt that would ssh to all the Pis and shut them all down?
• to network the Pis so their clocks all sync, and have some way of doing a timed shutdown?

As I will not be the one looking after these Pis long-term, I'm looking for whatever route is most robust, clean, and easy-to-use.

[DougieLawson]

Code: Select all

#!/bin/bash

ssh root@pi2 halt
ssh root@pi3 halt
ssh root@pi4 halt
ssh root@pi5 halt
halt

You'll need to use ssh-keygen on each pi to enable ssh login without a password. Share the public keys round the others so that every RPi has a private key and the public key for all five pis in /root/.ssh/authorized_keys

The shutdown command allows you to set a time when it shuts the system down.

sudo crontab -e

Add

Code: Select all

@reboot shutdown -h 18:30 # down at 6:30pm

and that will be run at boot up.

There's also the at daemon sudo apt-get install at
echo "halt" | at 18:30