I need to write a python script that autostarts on boot and is executed every 5 minutes on a raspberry pi. How can this be done? in particular, how can I avoid having a script locking up the cpu running a infine loop waiting for the 5 minutes to be over?
You can easily use cron for this task (schedule to run Python script). ;)
I suppose that you have cron installed already; if not, then install some (vixie-cron for an example).
Create a new file /etc/cron.d/<any-name>.cron with the following content:
# run script every 5 minutes
*/5 * * * * myuser python /path/to/script.py
# run script after system (re)boot
@reboot myuser python /path/to/script.py
where myuser is the user to run the script (it shouldn’t be root if possible, for security reasons). If this doesn’t work, then try to append the content to /etc/crontab instead.
You might want to redirect stdout/stderr of the script to file, so you can check if everything works fine. This is same as in shell, just add something like >>/var/log/<any-name>-info.log 2>>/var/log/<any-name>-error.log after the script path.