RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

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rbono459890
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by rbono459890 »

This is excellent work Magnus!

I am working on a simpler/less expensive version for motorcycles using a single read (not a matrix) device such as MLX90614.

How did you manage to compensate readings for distance?
The MLX90614 sensor has a wide aperture and reliable readings require close proximity in the few centimeters range (while I was hoping to mount the sensor no closer than 10cm).
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Magnus Thomé
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by Magnus Thomé »

Hi!

The MLX90621 doesn't need compensation for distance.

But it would be very easy to use the distance data from the VL53L0X to add that if the MLX90621 was made to use distance compensation.
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rbono459890
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by rbono459890 »

So rather than "compensation for distance", after some more testing it looks like the issue is related only to the MLX90614 sensor aperture: being quite wide, it detects an average temperature, which works for large surfaces but in the case of motorcycle tires it does not.

I am looking at mounting the sensor as close as possible (like some commercial solutions do) but it's at this point much more complicated, especially with the front tire.

Thanks for the tip and inspiration!
rkanaga
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by rkanaga »

Does this work with iPhone's please?

I think that Apple are a bit fussy about allowing any non-approved bluetooth LE devices to connect to IOS?

I would like to build 4 of these and connect them via BLE to my iPhone in addition to the XPS GPS unit I already have and a Go-Pro camera.

Thank you very much for a great software.
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Harry
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by Harry »

rkanaga wrote: Thu Dec 16, 2021 1:53 pm Does this work with iPhone's please?

I think that Apple are a bit fussy about allowing any non-approved bluetooth LE devices to connect to IOS?

I would like to build 4 of these and connect them via BLE to my iPhone in addition to the XPS GPS unit I already have and a Go-Pro camera.

Thank you very much for a great software.
BLE is completely open for iOS devices, Apple is not involved in adding BLE accessories. Approval is required for using BT SPP (and probably other non audio profiles) only.

Tire sensors are a niche and not used a lot, please let us know in case you run into problems.

- Harry
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rkanaga
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by rkanaga »

Thank you, that is good to hear. I've been getting great results with HLT and an XPS GPS-160 + GoPro Hero and want to take it to the next level. My car does not have OBD II sadly so I don't think there is an easy way to add sensors for throttle, brake and steering angle, but the Tyre sensors would be a great addition anyway.

Yes, of course I will let you know how I get on (the car is a BAC Mono by the way.)

Thanks for the very quick reply.
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by fernando.hiagon »

rbono459890 wrote: Fri Feb 26, 2021 4:03 am This is excellent work Magnus!

I am working on a simpler/less expensive version for motorcycles using a single read (not a matrix) device such as MLX90614.

How did you manage to compensate readings for distance?
The MLX90614 sensor has a wide aperture and reliable readings require close proximity in the few centimeters range (while I was hoping to mount the sensor no closer than 10cm).
Hi rbono459890
Could you provide the code you are using? I'm also trying to use the MLX90614 sensor. I would be very grateful.
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by Random Direction »

Hi Magnus,

A big thank you to you and Harry for the excellent effort you have contributed to this project. I have recently constructed a set of four sensors and fitted them to a Mazda MX5/Miata and collected data from my first track day using the RejsaRubberTrac system. Clearly there has been lots of effort in the design of this system and it is very well thought through. Now having collected and exported my first data set, it's time to start analysing.

Having reached this point, I am especially interested in analysing the wheel displacement data. Is your concept that we export the hlptrl file for a lap then extract and analyse the data from there?

Well done!

Best regards
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by Harry »

At least for LapTimer GrandPrix, you can find a by tire chart for laps recorded. To see it, open a lap from Lap List and follow Data Recordings / Charts. Swipe to one of the last pages showing the temperature development. In addition (and for GP), the video overlay will include a gauge showing tire temperature (16 temps / wheel).

The hlptrl format is used by LapTimer only.

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Bleak December
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Re: RejsaRubberTrac - 16 zones tire temps - bluetooth sensor

Post by Bleak December »

Hi Magnus

I am captured by your design and have started collecting the parts, however I am having problems to locate the IR sensors. Is this an equivalent board I could use? (Hope pasting links works):

https://a.aliexpress.com/_Ew79Yyj

Thank you in advance,

Cheers
Bleak
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