Thank you for your reply ,@Alex-Kushleyev .

I am indeed using a 12V AC/DC adapter.
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I inspected the problematic motor and found that its mounting screws did not appear to be screwed into the windings, as shown in the picture below.

Screenshot from 2025-12-22 17-06-21.png
Screenshot from 2025-12-22 17-06-36.png

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Here are the results of voxl-esc_spin tests using two different power supplies:

The 12V AC/DC adapter appears to be working fine (adapter_voxl-esc_spin_test_video) (adapter_voxl-esc_spin_test_result.txt

However, the battery power test results show:

Motor ID 0 is not working. (battery_voxl-esc_spin_test_video)

The Average RPMs of Motor ID 0 detected by the voxl-esc tools is significantly lower than the other three motors. The image below is a partial screenshot of the data. Please click the link for the complete data.(battery_voxl-esc_spin_test_result.txt)

Screenshot from 2025-12-22 17-32-26.png )

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Based on the above supplementary data, would you recommend that I send it for repair?

Thank you very much!

@YUUJI-INOUE I'm very confused by the voxl-px4.log file you attached. It is filled with a bunch of -- Reboot -- lines. Where do those lines come from? How did you generate voxl-px4.log? The only Accel #0 fail: TIMEOUT! I see is after a shutdown command has been issued to PX4. The Command failed is normal. The startup script attempts to do some auto-configuration by looking for devices that may not be attached to the drone and will produce those messages. Same with the i2c probe failed messages. The fact that you can fly in manual mode means that the IMU is fine.

@Alex-Kushleyev Thanks for detailed information and analysis. I am going ahead with further testing with this ESC as per your suggestion.

I have changed my propulsion system as follows: Emax Eco II seroes 2306 2400kv motor, propeller Gemfan 5177 and 15000 mah 4S battery.

Here is my file with ESC calibration : https://drive.google.com/file/d/1uzbx9MGwF1EvRqJx6tXBqqc-j3XZSgu_/view?usp=sharing

All the motor directions are checked and they are correct as per airframe reference. My UAV is able to takeoff a bit but at around 0.5 meters it again decreases its altitude and then after scratching the surface is flipping over.

Here is the logs : https://review.px4.io/plot_app?log=08691d7d-887d-41d8-b00d-d543febeea59

Can you spot is my ESC configuration wrong or anything I am missing in PX4 configuration? This flip happened twice in a row and all motor direction are verified to be correct since UAV is able to takeoff. Also any advantage of RPM vs PWM control in VOXL ESC PX4 parameter setup?

Also my voxl2 is unpside down so I have set ROLL_180 in Autopilot orientation, but is this creating some problem anywhere is unknown since I can see yaw reset EKF2 estimator flag set as soon as I takeoff.

@tom , what would be the right course of action here? Thanks!

Hello @Dronodev ,

The other side of the M0166 PCB has a picture of a tiny figure which shows the nominal "up" orientation. You will see the little guy in the image below (coax cables are going up):
12ab4ea7-33ae-4f8e-ad16-476834d79f4a-image.png

So if you flip the camera around to point away from you, then reference frame will be (right-handed):

X : right Y : down Z : out of the camera lens

So your first diagram (on the left) is correct.

Here is specifically what en_rotate flag in voxl-camera-server.conf does for AR0144 camera:

it sets the camera configuration / register such that the image is read out backwards (rotated 180 degrees) from camera to VOXL2 no rotation is done in software (voxl-camera-server)

If you enable the rotation this way, you will need to either re-do the camera calibration or rotate your intrinsics manually, which I guess is trivial.

In terms of extrinsics (in /etc/modalai/extrinsics.conf file), you will need to update the camera rotation by 180 degrees along the Z-axis, if en_rotate flag is used (assuming you had it already configured for the non-rotated configuration).

Alex

@Richa , you should find information you need in the links below:

https://docs.modalai.com/M0186/#module-connector-pinout-for-j1-s-h26-hr-ds-412 https://docs.modalai.com/micro-coax-user-guide/

Alex

Hello @awagner ,

I am sorry this happened to you. A few questions / comments:

It seems your motor is too large for this mini ESC

https://docs.modalai.com/voxl-mini-esc-datasheet/

"This Mini ESC is designed for aerial vehicles under 750g (under 500g for FPV racing applications). For larger slow flying vehicles up to 1500g, please use the VOXL 4-in-1 ESC. For FPV racers exceeding 500g, please use VOXL 4-in-1 FPV ESC."

the kp value is very aggressive (typically i would recommend starting at 0 kp and ki (proportional and integral gains) and ramp those up to increase responsiveness.

the spin-up type should be set to 1 (sinusoidal), since it is much more reliable. Which parameters did you start with when you calibrated your ESC? i suspect that improper spin-up caused the ESC to get out of sync and fail due to excessive current.

I know it can be difficult to get started with using new hardware. Aside from the need for updated esc parameters, the issue here is that the mini ESC is not suitable for your motors / propellers. I strongly recommend upgrading to our FPV ESC , which is build to handle a lot of power and stress:

https://www.modalai.com/products/m0138 https://docs.modalai.com/voxl-fpv-esc-datasheet/

Once you get the FPV ESC, I can help with the tuning (let me know, i can provide updated params before you test gain).

Please submit an RMA request, https://www.modalai.com/pages/rma . I would recommend at least a discount on the new ESC. We will try to improve documentation to avoid this in the future.

Alex

Hello @taiwohazeez ,

Thank you for sending updated images.

Just for sanity checking, please double check that the other tracking camera on your drone is in focus and does not have this issue.. (i assume that is true).

To me, it definitely looks likes either

damaged or dirty lens on the external lens surface damaged or dirty lens on the internal lens surface (the back surface of the lens) dirty surface of the camera sensor itself (inside the camera module)

If you are comfortable with unscrewing the lens completely and wiping it (front and back) with a new microfiber cloth (preferably long strand) and screw it back again to check if there is any improvement. Also, once you remove the lens, you can take a look at the sensor itself, any dirt or smudges should be very easy to detect because the surface of the camera sensor is very reflective and should be perfectly clean. I can't recommend cleaning the sensor itself on your own, since that would involve inserting something inside the camera module, which could lead to damage. Please dont keep the lens out of the lens holder for a long time (hours) as dust or dirt may get inside on the surface of the sensor (do not perform this procedure in a dusty environment).

Please reach out to https://www.modalai.com/pages/rma if you need further help to get this fixed / replaced.

Alex

@l05 , when in doubt, you can add a print statement in your app as a sanity check to make sure you are running the correct version of the application. Then check your print statement at run time.

If you are modifying an existing app in voxl-mpa-tools, you just need to use the voxl-cross docker image to

build the source code build the package (deb) deploy the package (either manually pushing and dpkg -i <package.deb> on target) or using a convenience script deploy_to_voxl.sh which is typically present in most voxl projects -- this script will push the deb to voxl2 and install the deb. run your new application on voxl and confirm functionality

If you are adding a new app to voxl-mpa-tools project, you will need to modify the CMakeLists.txt file in the tools folder, it should be self explanatory how to add a simple app. Once you build and deploy, your new app will be installed into /usr/bin on voxl2.

If you have any other questions, let me know.

Alex

Hello @shalini-kumari ,

The M0186 camera uses the Sony IMX664 sensor. You can find high level information for the M0186 module here https://docs.modalai.com/M0186/ (as well as a link to the basic documentation from Sony).

The camera sensor itself (within M0186 module) requires three primary voltages, 3.3V, 1.8V and 1.1V. The maximum power consumption is 0.6-0.7W (theoretical), although we have not explicitly measured it.This is for a worst case, full frame resolution 120FPS. VOXL2 and the M0186 module provide the appropriate voltages for the IMX664 sensor to function properly.

Note that the power consumption of the whole system will not only depend on the camera resolution, fps, it will also depend on what you are doing with the images in VOXL2 (since VOXL2 will also consume power processing the images).

Hopefully this helps.

Alex

@colombe-ai , when you flash a voxl2 SDK, there should be an option to set it up from scratch. did you try it?

https://docs.modalai.com/voxl-suite/

Alex

@taiwohazeez ,

Please try the following after a fresh reboot:

voxl-inspect-cam tracking_down tracking_front tracking_rear tof_ir hires_small_color

Running voxl-inspect-cam -a can break the camera server because there are too many output streams to process. This used to be a good option in the past for a quick test, but with 5 cameras and ~25 streams this is becoming too heavy. In normal use cases, only one stream is used from each camera.

If you are just getting started, I would suggest updating your drone to at least SDK 1.5 or even 1.6, however you should still be able to get camera streams displayed in voxl-portal or using the limited voxl-inspect-cam command.

If you still cannot get this to work, please do the following to stop the background service for voxl-camera-server and run in in the foreground and past the output:

#stop the background service (it will restart after reboot) systemctl stop voxl-camera-server #run camera server in foreground voxl-camera-server

Alex

Hello @taiwohazeez,

it seems your calibration pattern is significantly warped. It needs to be as straight as possible.

I personally like to perform calibration by displaying a pattern on an LCD screen (flat), which more or less guarantees it being straight. For a monocular calibration, the size of the box does not make any difference (no scale is recovered from the calibration). If you use that approach, then you actually have to move the camera as opposed to moving the pattern, unless you want to move the screen, which actually would be possible on a laptop. Watch out for reflections from screen and also sometimes setting manual exposure also helps (i won't go into detail how to do that here).

You could take your calibration sheet and glue it to a rigid flat surface, but even that can be tricky, since paper glue can cause wrinkles on paper, but those should not be as bad as the deformation seen in your screen shot.

Alex

@jmltt For reference, here is a commit that will allow our fork to build for SITL on Ubuntu 24.04: https://github.com/modalai/px4-firmware/commit/8366d2e56c171230ee31c0856cb243d46f09de31

@schew The ESC states are as follows:
0: idle / not spinning or trying to spin
1: spinning up
2,3: unused
4: very brief transition between spin-up and full back-emf sensing mode (user's commands are not yet executing)
5: back-emf sensing mode (rpm or power control based on user's command)
If there is any issue that causes ESC to think it's stalled or communication timed out, it will go through state 0 and then to 1 if non-zero commands are sent via UART.
The typical start-up sequence is basically 0->1->4->5 and should stay at 5 until you send a zero command or stop sending commands.

@alan123 Are you starting voxl-px4 from the command line (e.g. voxl-px4 -d) or is it starting automatically from a systemd service file on startup. If you have started it from the command line you can enter commands from the px4 shell. So, after the script is done, you can enter gps status to see that the driver is doing. If the driver hasn't been started, try starting it directly from the command line.

@Alex-Kushleyev Can you please look into this or tag someone who can help me solving this type of networking related issue?