# Tracking Camera Black Frames

Source: https://forum.modalai.com/topic/2058/tracking-camera-black-frames
Category: Development Drones (https://forum.modalai.com/category/44/development-drones)
Tags: m500
Posted: 2023-04-11 13:20:51 UTC by jay.miller
Replies: 8 · Views: 1765

## jay.miller · 2023-04-11 13:20:51 UTC

Hello,

We have a few m500 units, and one of them is having a strange issue with the tracking camera (hence qvio and tag detection as well). We are receiving frames, but the frames are black. Here is a screengrab from the voxl portal.

![1275530f-c502-4968-9ae0-ad9b48f6d220-image.png](https://forum.modalai.com/assets/uploads/files/1681218431372-1275530f-c502-4968-9ae0-ad9b48f6d220-image-resized.png)  

We can see frames coming across with `voxl-inspect-cam tracking`

There is no obstruction in front of the tracking camera. 

The problem is independent of if the qvio-server or tag-detection are enabled/disabled. Restarting the camera streamer or the entire unit does not fix the problem.

The calibration file hasn't been touched after receiving it as far as I know, but is the following:

`voxl:/data/modalai$ cat opencv_tracking_intrinsics.yml  

%YAML:1.0  

M: !!opencv-matrix  
   rows: 3  
   cols: 3
   dt: d
   data: [ 2.8075123128767450e+02, 0., 2.8251114752374190e+02, 0.,
       2.8033595591079933e+02, 2.4409310810431779e+02, 0., 0., 1. ]
D : !!opencv-matrix
   rows: 4
   cols: 1
   dt: d
   data: [ -5.3597885486553962e-03, 1.1906006300545838e-03, 0., 0. ]
reprojection_error: 1.8062384410858126e-01
width: 640
height: 480
distortion_model: fisheye
calibration_time: "1970-01-01 00:07:55"`

I've quickly checked the board connection and it seems OK, but I haven't fully disassembled anything, since the standoffs that support the stereo camera cross over the connection.

Please let me know if further information would be helpful or if there is a quick fix. 

Thanks!

## Reply by jay.miller · 2023-04-11 13:54:35 UTC

Quick update, this problem exists on another unit, also with PX4 firmware, v1.13.2, VOXL system image 4.0.0, voxl-suite 0.9.4

## Reply by jay.miller · 2023-04-11 14:02:55 UTC

For the unit that the tracking camera is sending visible frames, the tracking camera has exposure =4.1ms and gain=100 (from `voxl-inspect-cam tracking`) while the units that are having problems are showing exposure=32.99ms and gain=831. These have not been changed by hand, and I'm assuming the units that aren't working are maxing out the ranges trying to compensate for all black images.

## Reply by jay.miller · 2023-04-18 14:37:04 UTC

@modaltb Any help here? Are there other checks I should do to try to sort this out or plan on a return?

## Reply by Chad Sweet (ModalAI staff) · 2023-04-18 14:48:12 UTC

Assuming the software was not modified, the only thing left is an RMA. See https://modalai.com/rma

Each drone is flown one full battery with VIO before shipment, so it's odd this would appear now. Maybe the sensor came loose

## Reply by jay.miller · 2023-04-18 17:21:35 UTC (in reply to Chad Sweet)

@Chad-Sweet Thanks - the software wasn't modified to my knowledge, and some identical platforms are flying fine. If there is some cabling checks I can do, happy to troubleshoot those, I'm just not sure the best way to approach it with an assembled platform and don't want to do damage.

## Reply by jay.miller · 2023-06-01 18:38:30 UTC (in reply to jay.miller)

@Chad-Sweet or @modaltb any guidance on troubleshooting blank camera frames? Cables I can check without disturbing the cameras or anything? We haven't flown these platforms so I'd like to avoid an RMA if possible (but understand if that's the only path).

## Reply by Chad Sweet (ModalAI staff) · 2023-06-01 18:40:35 UTC

It would just be that tracking sensor and making sure it's connected to the VOXL. That being said, we haven't seen this in the past (which doesn't mean it's not a legitimate issue). Usually if the sensor is not connected, the camera-server fails

## Reply by jay.miller · 2023-06-06 15:43:50 UTC (in reply to Chad Sweet)

@Chad-Sweet Thanks. So it sounds like a full re-flash is probably the best check to re-install base software (I'm not aware of any modifications, but came onto the project after it started) and check that connection. If the issue persists with both units, kick off an RMA?

Appreciate all your help.