I have been trying to build something that will allow my robot car to navigate autonomously to a beacon indoors.
The first attempt at this using Bluetooth didn’t work:
https://blog.ciaopslabs.com/2026/08/02/bluetooth-beacon-fail/
mainly because Bluetooth doesn’t have enough range.
The second attempt using ESP-Now (radio) has also not really worked, this time mainly due to the signal reflections indoors.
Initially, I started off by just swapping out the Bluetooth beacon code for the ESP-Now code but that didn’t seem to actually work. I then simplified it down to just a beacon and a responder. In effect, I replicated a sonar system where the responder would beep faster the closer it got to the beacon.
After plenty of testing I discovered that the reflections due to the indoors environment made it next to impossible to get reliable directions using this process. I have however uploaded the bacon code here:
https://github.com/directorcia/Azure/blob/master/Iot/LLM/beacon.ino
and the responder code here:
https://github.com/directorcia/Azure/blob/master/Iot/LLM/llm-sonar.ino
the recommended solution is to use UWB, which would mean at least 2 senors like this:
https://core-electronics.com.au/challenger-rp2040-uwb-dwm3000.html
which aren’t cheap if I am just testing.
Another option is to move the project to using robot vision, which I was going to get to and have done before. However, I’m going to have a think about whether this is the direction I want to go or perhaps it is time to try something new?
CIAOPS Labs 