RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

[Magnus Thomé]

RejsaRubberTrac

Log and view tire temperature zones on race- and trackday cars

For around $100 per wheel you can build your own wireless sensors to log your driving. You'll then easily see if you are overheating the shoulder on one wheel in some particular corner, if one of the rear tires stays a bit too cold or if you need to adjust camber. And many more things about how you attack a course and how your car is set up.

- Temperatures are measured at sixteen different points over each tire's full width.
- A cheap distance sensor can optionally be added to also log suspension movement.
- Connects to Harry's Laptimer over low energy Bluetooth (BLE)
- Run two sensors for your front wheels only or monitor all four wheels.
- Run on built in rechargable battery or 12V directly from the car.
- Different housings available for different mounting in the wheel wells.

Complete info here: https://github.com/MagnusThome/RejsaRubberTrac


Early beta video:

[youtube]https://www.youtube.com/watch?v=Yuy62oPXugs[/youtube]

Early test 3D prints of housings

main housing early wip 2.jpg (667.95 KiB) Viewed 4585 times

main housing early wip 1.jpg (540.95 KiB) Viewed 4585 times

[jwmelvin]

This is awesome, thank you for your work on it and for posting!

[bulls23]

Amazing project! Are you planing on selling fully assembled sensors including enclosure?

[Magnus Thomé]

Amazing project! Are you planing on selling fully assembled sensors including enclosure?

Personally I am not. But there is interest from others to be able to manufacture and sell both complete fully assembled sensors and half assembled kits. So it looks promising to buy complete sensors.

Anyone with some basic soldering/computer knowledge can build sensors to their friends if they want. If someone wants to make these commercially they need to contact me first.

[Magnus Thomé]

Finally winter is over and I've been to this years first track meet and AutoX!!!!



Slow slalom (Toyo R888R):

https://www.youtube.com/watch?v=06vPpV8Tmns

High speed slalom course (Toyo R888R):

[youtube]https://www.youtube.com/watch?v=oOrpsQ6g-g4[/youtube]
(here you can see a bit higher temps at the end of the first run and in the end of the second run in the video)



First track meet (Normal street tires, a bit too low temps):

https://www.youtube.com/watch?v=jMsMUV9xTCw



- The OBD2 data, temps and video are not 100% in sync, it's a few tenths of a second off. Sorry for that.

- The tire temps are a bit low for the color scale, everything below 40 degrees celsius is just black. And the tire surface cools quickly on the straights. But the colors need to take account for higher temp tires too of course.

- The sensors are mounted in front of the tires which results in a lot of side movement when turning. Mounting should be moved up more above the tire, hitting the top of the tire.

[Magnus Thomé]

Another video, nicely synced this one:

https://www.youtube.com/watch?v=lrYU6CJ73co

[Magnus Thomé]

I solved the mounting on my BMW M2. Perfect location right above the tire. This means minimal tire movement in the sensor's field of view during turning and perfect for measuring distance to tire. The 120 degree angle field of view thermal camera sensor is used, the distance is about 9-10cm when stationary so the full tire width is well inside the FOV.

I made a small 3D printed snap-in holder and just a small hole in the plastic inner fender.

I just open the hood and reach in to remove the sensor from the snap-in holder or turn it on or of.


Do these pics work? They are hosted elsewhere so I'm not 100% sure they can be viewed here...

[mithridates]

Good afternoon, I just finished assembly of my sensor and have all code uploaded. I am able to see readings coming through on the serial monitor. I have also been able to connect to the sensor via bluetooth. When I go to add the sensor in Harry's I am only given the option to connect it as a sensor of type GPS or ODB. How do I get it to connect as a tire sensor?

[mithridates]

Any idea on how to connect the sensor to Harry's? When I go to add it, I am only seeing the option to connect it as an ODB or GPS sensor. No TPMS option that I can see.

[Harry]

Any idea on how to connect the sensor to Harry's? When I go to add it, I am only seeing the option to connect it as an ODB or GPS sensor. No TPMS option that I can see.

RejsaRubberTrac uses Bluetooth Low Energy to connect. You do not need to add it to Sensor List manually. Instead, make sure the Bluetooth Low Energy Expert Setting is ticked (LapTimer ‣ Administration ‣ Settings ‣ Expert Settings). For Android, it is off by default.

- Harry