There’s three general ways to tell whether something is there or not, and they all serve different purposes:
- GPS - fantastic for where in the world, and not so fantastic for home/away. Updates can be slow, (in)accuracy can put you home when you’re not, or not home when you are. Don’t use it for home/away
I use GPSLogger for this, as I’m on Android, but there’s a long list of options on the HA site (Life360 is often suggested, but I’ve never used it). - WiFi/local network - I use the
nmap_trackerfor this. It’s great for devices, and so-so for mobile phones. Mobiles often turn off WiFi when in deep sleep, so suddenly you’re no longer home. - Bluetooth - I use monitor, but you can use the built in
bluetooth_tracker. Phones don’t turn this off automatically, and battery drain from leaving BT on is irrelevant these days.
For mobiles you want multiple trackers. What if your phone turns the WiFi off? What if you move to a location in the house where it’s no longer in Bluetooth range? A group of trackers (or even something more advanced) means you’re not flapping between home and away.