Ranger Finder Not providing consistent data - Matek 3901-L0X - SOLVED

I’m trying to get the Matek 3901-L0X working and the range finder is giving me some trouble.

Matek F405-STD. AC 4.1dev.

When I perform the range finder and optical flow tests on the ground they seem to work just fine. Here’s the link for the ground test log. At this point the range finder is giving good data up to ~1.5m and only drops off when I’m doing the X and Y tests for the optical flow.


Now when I go fly it the range finder drops off right away. From what I can tell OF is still functioning, but I don’t notice anything in flight to suggest it’s doing anything. (Position and altitude still “wander” as normal like they do with out the RF or OF) . This test was mostly over gravel, but I’ve also flown over snow, grass, mud and none of that seems to change anything.


Any suggestions? Thanks!

Hi @Allister,

Could you provide some info about the light conditions of your test flight?
Why I am asking? The Matek 3901-L0X uses a VL53L0X ToF sensor.

My experiments with this type of sensors gave disappointing results in bright sunlight conditions.

Hope this helps.

Wow, that nails it on the head. I didn’t know that bright light would be such an issue. I was expecting low-light to be a problem.

My first test on the weekend was a clear blue day over an open field of smooth clean snow. It doesn’t get much brighter. The flight I referenced in my original post here was also in sunny conditions with a lot of snow around. So that means that sensor is going to be of very limited value for me. I may have to try an indoor test in ALT-Hold just to see how it works.

Thanks @VRquaeler! I appreciate your feedback.

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Hi Allister,

Thanks for the feedback. Glad to help. Please let us know how it turns out at indoor light conditions or at dusk light.


Hi @VRquaeler,

I just did a quick 1 minute flight in the garage and sure enough the rangefinder is giving me data. I’d say you called it. The range finder data seems reasonable. I can’t comment on the optical flow function because hovering in the garage at ~1m is often sketchy at best.

I’ll say I’m disappointed in this sensor. It never occurred to me that it would be so sensitive to day-light levels.

Anyhow, thanks for your help!

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