Hey Magnus,

First of all - a huge thanks for putting the software and guide together. It's a seriously impressive feat.

I was hoping you could help me out with some troubleshooting. Here are the parts i'm using:
- nRF52832 Bluefruit Feather
- VL53L0XV2
- MLX90621 GY-906LLC-DCC

I've loaded up your software and I'm able to get data from the laser distance sensor (transcribed into suspension travel) on RaceChrono, but no matter what I try I can't get any temperature data. (I'm seeing 0C)

I know I'm not using the sensor recommended - could that be the issue? I've checked that all pins on the daughter board are recieving 3.3V and none of them are bridged. I'm out of ideas.

I'm having an impossible time finding a seller for a MLX90621 GY-906LLC-BAA that includes the daughter board. Any suggestions? My car is too low to use GY-906LLC-BAB.

Thank you from Canada!

All MLX90621 version works fine.

Have you tried opening the serial terminal on the USB port to see what you get there?

Hey, thanks for the response.

I have. I'm seeing "0" across the board for temperature.

Are there any other troubleshooting steps you'd recommend?

Do you have two boards/sensors and both do the same or is it just one that is misbehaving? I once received a broken sensor, DOA. I wish I could remember how it behaved though, if it resulted in all zeros or something else. But I got it replaced and everything worked immediately when replacing it.

Obviously the I2C bus is working so it can't be that.

I have two sensors, and I've had them both with the same result.

I'm thinking that I'll try a new bluetooth board and a new sensor to see it that produces a different result.

Can you recommend somewhere I can buy a MLX90621 GY-906LLC-BAA from?

This is the only place I've found, but it doesn't include a board: https://www.mouser.ca/ProductDetail/Melexis/MLX90621ESF-BAA-000-TU?qs= . . . .

I've never seen the wide 120 degree BAA sold with a board actually. But you really don't need it. I have built units with 120 degree sensors myself.

Since the distance sensor works there can't be any shorts on the i2c bus SDA or SCL.

Did you measure very roughly 2,7 volts directly on the temp sensor power pin?

And triple checked that the temp sensor is mounted correctly rotate wise? The newer 90640 has a changed pin layout (it's rotated with the protruding tab indicator at a different angle) but AFAIK the 90621 has never changed, I've only seen one pin layout and tab orientation for it.

I'll check voltage to the sensor PIN when I get home today. Last time I checked, I believe it measured roughly 3.3v. This was with the board plugged into a laptop, not battery powered.

The sensors came mounted to the board so I'm thinking I can rule out them being mounted incorrectly. I was trying to have to avoid needing to mount the sensor to the board myself.

Oh, wait, I didn't read properly, I was thinking you already had the 120 degree wide sensors without board. You have the one with a board.

Are you sure it's a 90621 on the board and not the completely different 90614?

Yep, unless Aliexpress lied to me lol. I'll check actual boards again when I get home tonight.

So I just had the exact same thing, distance working fine, temps not coming through...

Turns out, 90621s are _really_ hard to get/expensive now, and AliExpress sellers are selling 90614s under the same entry. Now if you read carefully the "color" selection explanation tells you it's a 90614, but it's really unclear that it's not a 90621, as everything else talks only about 90621.

So I have 4 90614s sitting here, so yeah... this happened: https://github.com/MagnusThome/RejsaRubberTrac/pull/3

Doing some measure tomorrow to see if I'll order MLX90640s or AMG8833s, but figured in the meanwhile, why not add support for the 90614 and post here to help people figure out what might be going on if they have the same problem.

Good idea Thanks!

Being completely github illiterate (I only use it as a web page server to publish stuff really ) I just need to read up how to merge (which is probably just clicking the button or something)

Soooo, I made the PR with the AMG8833 branch as base, and requested to be merged into that, so yes, that would be a "hit the button" situation.

However, it's a good idea to merge the AMG8833 branch into master at some point, if you think all the changes you've made are ready for the main stage, so to speak. However, since you've made changes to master since then, the merge won't be automatic.

I have done git(hub) stuff for a living for a very long time, I can probably do make a pull request that's one click merge for you, that does the merging. Let me know what you'd like to do.

DocWilco skrev:

So I have 4 90614s sitting here, so yeah... this happened: https://github.com/MagnusThome/RejsaRubberTrac/pull/3 Doing some measure tomorrow to see if I'll order MLX90640s or AMG8833s, but figured in the meanwhile, why not add support for the 90614 and post here to help people figure out what might be going on if they have the same problem.

Even though I don't use RejsaRubberTrack (yet???) I must write: Great work!!!

DocWilco skrev:

Soooo, I made the PR with the AMG8833 branch as base, and requested to be merged into that, so yes, that would be a "hit the button" situation. However, it's a good idea to merge the AMG8833 branch into master at some point, if you think all the changes you've made are ready for the main stage, so to speak. However, since you've made changes to master since then, the merge won't be automatic. I have done git(hub) stuff for a living for a very long time, I can probably do make a pull request that's one click merge for you, that does the merging. Let me know what you'd like to do.

Merge your update with the AMG8833 branch should be easy.

I would like to merge that with master but honestly it's almost a complete rewrite so it would probably more be a keeping of my documentation pages as is and moving all the code over as a sort of "v2.0" version. And there I kind of stopped and let it be. Also the current main branch/release 1.0 is very very well tested. The branch I added AMG8833 to was heavily rewritten by Torben and Mark and I really don't know if it has some quirks or not in it. I haven't used it IRL and if they've used that or other branches when on track I don't know. So... that's about where I am :-)

Can one keep v1.0 as is and have "v2.0" as a separate choice for anyone wanting support for the new sensors and willing to test and see how it works?


Help is always deeply appreciated

I would recommend making a v1 branch starting with latest commit, and then merging the amg8833 branch into master. And then the v1 branch can be used for bugfixes for v1 releases.

Want me to make a PR of the amg8833 to master merge? It'll be a lot of importing documentation stuff from master, like you said.

DocWilco skrev:

I would recommend making a v1 branch starting with latest commit, and then merging the amg8833 branch into master. And then the v1 branch can be used for bugfixes for v1 releases. Want me to make a PR of the amg8833 to master merge? It'll be a lot of importing documentation stuff from master, like you said.

Since I'll be asking a number of very stupid questions maybe we should bounce this back and fourth over email instead?

Absolutely, can also do Discord or other things if you want.

DocWilco skrev:

Absolutely, can also do Discord or other things if you want.

Start with mail? magnust@gmail.com