Going for a bike ride in the forest, to test how well Meshtastic performs as a live-tracking platform.
Setup
- Nodes as described in https://klonoot.mataroa.blog/blog/20260904-live-tracking-experiments
- Base node in built-up environment facing the "wrong way" from sending node
- All messages sent via an encrypted channel, rather than a DM
- A bike ride from the centre of Nürnberg to Kalchreuth, roughly 8km away.
- There are two nodes in Kalchreuth, which lies ~100m above Nürnberg
- Companion node kept either in frame bag, or in handlebar bag with LoRa antenna poking out
Outcome
- After ~5 minutes, no more messages made it back to the base node
- Messages before then were not properly saved in local DB
- While riding, not possible to get a traceroute back to base node at any point
- After checking again (by going through the logs from the base node itself), two things jumped out:
- The timestamps from the logs themselves are not reliable -- they were all within two minutes of each other. Not sure whether this is actually the time when the log was exported from the node. Very weird.
- The altitude of all the messages from the companion node was always 305m. Turns out it was broadcasting a fixed position the entire time, which was my fault. I had set it up that way to make it easier to figure out the byte sequence of the decrypted packet payload.
Possible causes
- Companion node powered by power bank, which with these boards has been extremely unreliable. They have turned themselves off multiple times in the past. I did not notice this while on the bike, but still possible
- Base node posting to MQTT broker on laptop, which might have fallen "asleep"
Remediation
- Setup local env on mini PC which never falls asleep
- Look into a different board
- The unreliability of the XIAO ESP32S3 has been implied by others: https://anarc.at/services/meshtastic/
- Better antennae will almost definitely help while in the forest anyway
- Create some kind of testing infrastructure (or use something pre-built) to isolate the behaviour of the radios themselves
Bike Ride
- Very nice
- Sunny
- Observed over ten (10) cool dogs
- I received two (2) free beers
Franconia smiles upon me.
