Thanks for the input, @cruunnerr and @martinkooij.
I ended up going with @cruunnerr’s approach as it required fewer changes to my existing setup.
Here is what I did:
Created a file that lists the devices and their IPs that we want to evaluate. Filename: “devices”. myphone,192.168.0.200 mywatch,192.168.0.201 wifephone,192.168.0.202 wifewatch,192.168.0.203 Created a perl script, “ping.pl”, that pings the devices listed in the file. If it gets a response it will write the results to a file named “ping_results”. #!/usr/bin/perl use Net::Ping; open(INFILE, "; close(INFILE); #open(OUTFILE, ">", "ping_results") or die("unable to write output: $!"); chomp(@ip_array); $p = Net::Ping->new(); foreach(@ip_array) { if($_ =~ /\d+.\d+.\d+.\d+/) { if($p->ping($&)) { open(OUTFILE, ">", "ping_results") or die("unable to write output: $!"); print OUTFILE ("$`is responding to ping.\n"); close(OUTFILE); } } } Added a crontab job to run the perl script at 04:55. # m h dom mon dow command # Execute Perl Script to check for devices 55 4 * * * perl /home/pi/ping.pl Created a shell script, “rpi-hdmi-on.sh” that will check to see if “ping_results” exists. If it does it will turn the monitor on and then delete the “ping_results” file. Added a crontab job to execute this script at 05:00. if [ -e ping_results ] then vcgencmd display_power 1 >/dev/null rm -f /home/pi/ping_results fi # m h dom mon dow command # Turn HDMI On (05:00/5:00am) 0 5 * * * /home/pi/rpi-hdmi-on.sh Created a shell script, “rpi-hdmi-off.sh” that will turn the monitor off. Added a crontab job to execute this script at 21:30. vcgencmd display_power 0 >/dev/null # m h dom mon dow command # Turn HDMI Off (21:30/9:30pm) 30 21 * * * /home/pi/rpi-hdmi-off.shI’ve done some testing and it seems to be working well.