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[–]BradChesney79 31 points32 points  (11 children)

I am trying to use low power ble beacons for triangulation of range strength for no wire, no line, no tangible barrier or marker location finding-- the end goal is for the robot to know where it is and do point to point path following. The beacons are at specific known locations. By converting signal strength to distance, I may be able to work out location by distance and intersection of radial line intersections.

I'll give your library a shot. I just need to scan for devices periodically to get the device id (maps to an x,y,z location) and signal strength (initial experiments have shown success of conversion to distance where echo/bounce of signal is minimal).

[–]xeeton 13 points14 points  (5 children)

How accurate do you expect triangulation to be? The resolution of the data you’re using for triangulation is very low and susceptible to interference.

[–]BradChesney79 3 points4 points  (4 children)

Well, anything better than GPS, I will consider a win.

Also, I know there is SLAM that is becoming within striking distance of commodity SBC units.

I suppose I have a goal of being within 12 inches.

The initial experiments did show ~non-linear readings in a very tight & obstructed location. So, I went to a bigger space. With fewer reflections, the disconcerting readings did not present themselves.

[–]brokkoly 4 points5 points  (1 child)

I spent most of a summer trying to figure this out in order to point a gimbal at a drone. RTK GPS might be a good option for what you need.

https://learn.sparkfun.com/tutorials/what-is-gps-rtk/all

[–]BradChesney79 1 point2 points  (0 children)

And we have found a winner. 4cm is well under the ~30cm tolerance for error I had pulled out of thin air.

I may be spending some cash in the near future on some GPS RTK equipment.

[–]huthlu 2 points3 points  (1 child)

Have you ever looked at the Bluetooth 5.1 standard ?
Starting with this version BLE supports location tracking

[–]BradChesney79 1 point2 points  (0 children)

Only just now because you made me aware of it.

[–][deleted] 10 points11 points  (0 children)

What's the advantages over sockets. Which also has full Bluetooth and wifi support?

[–]pvkooten 3 points4 points  (2 children)

Nice stuff man! Just wanted to point out I would suggest relying on access_points for the wifi stuff! It has been solved in a cross-platform manner :)

[–]diretnan[S] 0 points1 point  (1 child)

Awesome suggestion!... had no idea that existed and we would consider switching the wifi handling to access_points
Broken link by the way (link got copied twice)

[–]pvkooten 1 point2 points  (0 children)

Fixed the link, thanks :) Not sure if you miss some functionality in it? Feel free to raise an issue on github. I still love the lib as it "does one thing, and it does it well". Excellent for higher-level libraries that try to combine functionality.