You may have gotten here from my hyperion with nagios writeup, this doesn’t follow on from that and is separate, but maybe of interest.
The basic idea: I’ve now got LED’s in my room and would like them to come on before I go to bed so I can see without falling over. The ones on the stair I just leave running, but like hell am I going to sleep with such a bright LED (I probably could, I can sleep in the day but I thought it would be a better idea for them to come on ready).
I could have just set this up on a basic cron and picked a time early enough to account for summer/winter before I go to bed. but where’s the fun in that. I know my PI can work out when the sunrise/sunset is. so it can’t be that difficult to set something up.
After a little bit of searching I come across sunwait you will need this or a similar program. I wont cover installing sunwait on the PI here. just the config I use with hyperion.
First I need a script that sunwait will call and tell it what it needs to do. Here’s my sun-light.sh
#!/bin/bash
COMMAND=hyperion-remote
COMMAND_PRIORITY=50
COMMAND_PATH="/usr/bin"
case "$1" in
sunset)
/usr/bin/hyperion-remote -p 50 -e "Knight rider"
;;
sunrise)
/usr/bin/hyperion-remote -p 50 -e "Little Chaser Blue"
;;
*)
echo "Usage: $0 {sunrise|sunset}"
exit 1
esac
exit 0
Don’t forget to make this script executable ‘chmod +x sun-lights.sh’
This is basically told to either run sunset or sunrise and will then call hyperion-remote passing the relevant priority and effect. (Little Chaser Blue is a copy and customisation of Knight Rider)
Then I added the following to /etc/crontab
0 02 * * * root sunwait -p sun up 51.xxxxN 3.xxxxW ; /root/sun-lights.sh sunrise 12 02 * * * root sunwait -p sun down 51.xxxxN 3.xxxxW ; /root/sun-lights.sh sunset
This basically run’s sunwait which will wait until the sun is either coming up or going down at the specified co-ordinates before running the bit after ;
The important bit to get your head around if you must have cron run this at a time well before the sun will rise or set. midnight and midday seems like a good safe bet.
I know I’ve skipped over the actual installation of sunwait and more details on hyperion and running the scripts to check it works, but it’s 1am and I just want to save this 🙂 So if you’ve got this far and are still confused, comment below and I’ll expand on the relevant bits.