Ask HN: Most interesting tech you built for just yourself?

My current favorite: I often go camping deep in the backwoods with friends, far from any sort of cell service. So I built a LoRa radio system that allows us to text each other, physically locate each other, etc. when we go off and do our own things. The system consists of small radio units that are carried, and a larger (but still backpackable) base unit that gets set up in camp.

They run as a mesh network, so you don't have to be in range of the base unit for it to work.

Regular radios don't work well for this use case because the terrain is very mountainous.

Currently looking into making one that can be attached to a dog collar to allow for geolocating the animal.

This is very cool, and something I could see myself setting up for my friends while camping as well. Are you able to share more details about your setup? Thanks!

Sure. The radios are inexpensive ESP32 LoRa dev boards (with good antennae and 3D printed enclosures), and the software is a modified version of Meshtastic. This is the article that inspired me -- I think that will lead you to more detail about what I did than I can give here.

https://hackaday.com/2020/02/26/lora-mesh-network-with-off-t...

These perform better than the Baofeng radios we used before, but the terrain is still a limiting factor.