+ set to keep the GPS on during suspend
- use the gpsd protocol to know if there is a fix or not
- suspend/resume hooks to put the GPS into low power mode
+ - log
+ - timestamp, coordinates
+ - message (structured) (json?)
+ - instant or period (start, end). Period have timestamp and coordinates at
+ start and end. And GPX track of trip.
- alarm
- log unacked alarms
- play sound at alarm trigger