Mesh Networking the LIDAR elements together ESP8266 <> ESP32

One step further in attempt to make a wireless system between the base rover station and the spinning Laser module.


In a Nutshell :-

Using an ESP8266 with attached (i2c)Time of Flight laser module VL53L0X , loaded with "PainlessMesh" program.

The base station rover ESP32 is also loaded with the "PainlessMesh" program.

Then they search and find each other and a channel is opened to transmit packages of live data over its kinda adhoc Wifi path.

What this means is that there will be no physical wires between the two modules, so you can spin the TOF ESP8266 without fear of wires tangling or noisy spin contact couplers.



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GroG's picture

Awesome Gareth !!  Brilliant,

Awesome Gareth !! 

Brilliant, you've made a RF Slip Ring !

Pefrect for fast spinny electronic things like Lidar Scanners 


Gareth's picture

Delayed(xxxx) <> Mesh network == NoNo

"Slip Ring" escaped me when I was trying to remember the mechanical variant.

After this video I started to wind up the speed of the data transfer (debug was turned on by default ... which was also transfered over the mesh network - the RX counter was doing overtime, killing debug gave just the pure data TX - phew).

Unfortunately inclusion of "delay(xxxx)"  in the Laser Time of Flight code killed the continuity of the data transfer ..Gahh, somewhere in the TOF libraries there must be a delay(xxxx) element putting a bent spanner in the works.

Sending pure variables over the mesh network presents no problems !!!

So now working on Plan B and a Plan C :-

Plan B :- Run the mesh network code on one core of the ESP32 and the TOF on the second core.

Plan C :- I will do this anyway for fun...

  1. The top spinning ESP32/ESP8266 will TX data into an IR LED.
  2. The Bottom ESP32 will have an IR detector (LED!!!)
  3. My stepper has a hollow drive shaft.
  4. Shine the TX LED through the Shaft and the RX will pick the serial data.
  5. Its an enclosed system (lightwise) so I think I can get away with just LEDs.
Gareth's picture

Going with Plan "C"

Looks like I have quickly plumped for  Plan "C"

Basically TX_ing data over IR link through the hollow Stepper shaft.

As calculated because the system (hollow stepper shaft) is not exposed to ambient light and there is maybe 2cm gap between IR TX and IR RX sensor there is a massive signal, and definite logic level swing.

Credit goes to the MRL Elves...

Gareth's picture

Elves are messing around with the ॐ

The hardware Elf has just informed me that he changed the 100kΩ on the TX Led to 100Ω (for 20mA @3.3V)