@dlee ,

Yes the new TOF sensor (IRS2975C) is more powerful that the previous generation. What I mean by that is that it can emit more IR power but also heats up more. Emitting more power allows the sensor detect objects at larger distances or objects that are not as reflective.

In current operating mode, the auto exposure control is enabled inside the sensor itself, which modulates the emitted IR power based on the returns that the sensor is getting. That is to say, the power draw will vary depending on what is in the view of the sensor. If there are obstacles nearby, the output power should be low, otherwise it can be high. At full power, the module can consume close to 0.8-0.9W

So the first solution, if design allows, is to add a heat spreader to dissipate the heat, which you already started experimenting with. The sensor has a large exposed copper pad in the back for heat sinking purposes for this exact reason. Just be careful not to short this pad to anything, use non-conducting (but heat transfering) adhesive pad between the sensor and heat spreader.

In terms of a software solution to the issue, we can query the temperature of the emitter. We can also control the maximum emitted power used by the auto exposure algorithm. That is to say, still leave the auto exposure running in the sensor, but limit the maximum power that it is allowed to use.

We are planning to add some software protection that limits the maximum output power as a function of the emitter temperature. This will require some implementation and testing.

Meanwhile, please consider using a heat spreader, which will be the best solution if you want to make use of the full sensor's operating range and not have our software limit the output power in order to prevent overheating.

Hello @Kashish-Garg-0

we have a curve that is "motor voltage vs rpm", meaning that for a desired RPM, it tells the ESC what average motor voltage should be applied. The average motor voltage is defined as battery_voltage * motor_pmw_duty_cycle. The battery voltage in this curve is in millivolts. Since you are typically controlling the desired RPM, as a user you do not need to worry about what "throttle" or voltage to apply - the ESC does this automatically in order to achieve the desired RPM. this calibration curve is used as a feed-forward term in the RPM controller. The ESC does support an "open loop" type of control where you specify the power from 0 to 100%, which is similar to a standard ESC, but PX4 does not use that ESC control mode.

By the way, you can test the ESC directly (not using PX4) using our voxl-esc tools (https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/tree/master/voxl-esc-tools) which works directly on VOXL2 or a standalone linux PC (or mac). voxl-esc-spin.py has a --power argument where you specify the power from 0 to 100, which translates directly to the average duty cycle applied to the motor.

Here is the calibration for the Starling V2 motor / propeller that we use:
https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/master/voxl-esc-params/mavic_mini_2/mavic_mini_2.xml?ref_type=heads#L63

Also, you can take a look at this post to see how to interpret those parameters a0, a1, a2 : https://forum.modalai.com/topic/2522/esc-calibration/2

We also have some dyno tests for this motor / propeller : https://gitlab.com/voxl-public/flight-core-px4/dyno_data/-/blob/master/data/mavic_mini2_timing_test/mavic_mini2_modal_esc_pusher_7.4V_timing0.csv . We are not sure how accurate that is, but it can be used as a starting point. @James-Strawson can you please confirm that is the correct dyno data for the Starling V2 motors?

Alex

@reber34 , perhaps this approach can work for you:

• record a video encoded at high bit rate (using voxl-camera-server and voxl-record-video . Please note that the output of voxl-record-video will not be in a standard container (such as mp4, etc), but you can fix it with ffpeg : ffmpeg -r 30 -i voxl-record-video.h264 -codec copy videofile.mp4
• re-encode the video offline with desired codecs / bit rates / resolutions
• install gst-rtsp-launch which uses gstreamer to set up an RTSP stream https://github.com/sfalexrog/gst-rtsp-launch/
  • you will first need to figure out what gstreamer pipeline to use on voxl2 that will load your video and parse the h264/h265 frames (can use null sink for testing) and then use that pipeline with gst-rtsp-launch which will take the encoded frames and serve them over rtsp stream.
• gstreamer may be more flexible for tuning the encoding parameters of h264/h265 (compared to voxl-camera-server) and you can also use it in real time later (using voxl-streamer, which uses gstreamer under the hood)

Another alternative is to use voxl-record-raw-image to save raw YUVs coming from voxl-camera-server and then use voxl-replay and voxl-streamer - the latter will accept YUVs from the MPA pipe and encode them using the bit rate that you want. Note that depending on the image resolution, YUV images will take a lot more space than encoded video, but maybe that is also OK since VOXL2 has lots of storage.

Alex

@smilon ,

I believe you are correct! Thank you. We will double check this and fix.

Hi

If you are looking for more low level functionality and a bit easier to experiment with, you may want to check out https://gitlab.com/voxl-public/utilities/voxl-rtsp/-/tree/dev . This tool is good for testing or running simple scenarios. This tool accepts some commands (like exposure control) via command line, so you could add a simple feature to save an image upon a command line input. Please see README to see how the exposure control input works and code for how it's implemented.

Please make sure that voxl-camera-server is disabled when you run voxl-rtsp.

If you still would like to go through the voxl-camera-server approach, we may need some more input from respective devs :).

I hope this helps..

Alex

Hello @Gicu-Panaghiu,

I am going to assume you are using VOXL1, since you did not specify..

We do have RAW8 and RAW10 support for OV7251. The selection of the format has to be done in several places.

First, you have to select the correct camera driver, specifically..

ls /usr/lib/libmmcamera_ov7251*.so
/usr/lib/libmmcamera_ov7251.so
/usr/lib/libmmcamera_ov7251_8bit.so
/usr/lib/libmmcamera_ov7251_hflip_8bit.so
/usr/lib/libmmcamera_ov7251_rot180_8bit.so
/usr/lib/libmmcamera_ov7251_vflip_8bit.so

there are 5 options and one of them is _8bit.so which means it will natively ouptput 8bit data (all others output 10 bit data).

the driver name, such as ov7251_8bit has to be the sensor name <SensorName>ov7251_8bit</SensorName> in /system/etc/camera/camera_config.xml.

You can check camera_config.xml for what sensor library is used for your OV7251.

When you run voxl-configure-cameras script, it will actually copy one of the default camera_config.xml that are set up for a particular use case, and I believe it will indeed select the 8bit one - this was done to save cpu cycles needed to convert 10bit to 8bit, since majority of the time only 8bit pixels are used.

Now, you mentioned that HAL_PIXEL_FORMAT_RAW10 is passed to the stream config and unfortunately this does not have any effect on what the driver outputs. If the low level driver (e.g. libmmcamera_ov7251_8bit.so) is set up to output RAW8, it will output RAW8 if you request either HAL_PIXEL_FORMAT_RAW8 or HAL_PIXEL_FORMAT_RAW10.

So if you update the camera_config.xml to the 10bit driver and just keep the HAL_PIXEL_FORMAT_RAW10 in the stream config (then sync and reboot), you should be getting a 10 bit RAW image from the camera. But since the camera server is currently expecting 8 bit image, if you just interpret the image as 8 bit, it will appear garbled, so you will need to handle the 10 bit image (decide what you want to do with it) in the camera server.

@wilkinsaf , M0027 was never shipped to any customers, as it was a test version of the ESC. So there should only be M0049, M0117, M0134 and M0129 (mini) ESCs out there. Like Vinny said, all of those ESCs have a blue status LED for each MCU.

If your ESC has a larger rectangular shape (as opposed to a square), it could be a really old ESC (Atmel-based, not STM32-based), which we do not really support any more. I hope this helps!

Alex

The ipk is available here now : http://voxl-packages.modalai.com/stable/voxl-hal3-tof-cam-ros_0.0.5.ipk - you should be able to use the launch file to choose between two modes (5=short range and 9=long range) and fps, which are listed in the launch file.

@Prabhav-Gupta , yes it seems like OpenCV and ROS YUV_NV12 formats do not match up. I will take a look at it.. it seems the ROS YUV is packed (interleaved) while standard for storing YUV NV12 is having two planes : plane 1 : Y (size: widthheight), plane 2 : UV (size: widthheight/2)

In the meantime.. you can stream a rtsp h264/h265 from VOXL (use decent quality so that image looks good) and use opencv to receive the stream and get decompressed images: https://stackoverflow.com/questions/40875846/capturing-rtsp-camera-using-opencv-python

Would that work for you ? (unfortunately with rtsp stream, you will not get the full image metadata, like exposure, gain, timestamp, etc).

RTSP streaming can be done using voxl-streamer, which can accept either a YUV (and encode it) or already encoded h264/5 stream from voxl-camera-server.

Alex

.. or if you wanted to continue using voxl-camera-server for 4K, just modify the server to save yuv frames on-demand and convert to jpeg later, as we discussed above..

M0153 step file : link

@JackHammer no problem.

This should be the esc param file for the Starling 2 Max motor : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/dev/voxl-esc-params/D0012_Starling_MAX/esc_params_m0129_f2203_5_1500kv_7x3.7x3.xml

The param file should also be present in /usr/share/modalai/voxl-esc-params

Do you know how to update the esc parameters?

systemctl stop voxl-px4
cd /usr/share/modalai/voxl-esc-tools
./voxl-esc-updload-params.py -p <full path to params file>

After updating the params, you can run a "power ramp test", as shown here : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/dev/voxl-esc-tools/doc/low_kv_motor_tuning.md?ref_type=heads#power-ramp-test . Use id=255 to spin all motors (and you can limit power to 80%)

./voxl-esc-spin.py --id 255 --power 80 --ramp-time 3.0 --timeout 3.5 --enable-plot 1 --cmd-rate 250

Since you can't display the plot on voxl2, a plot will be saved as html, which you get download from voxl2 and view in a browser.

You can do it without propellers (for safety). If all the motors are working properly, the four rpms will be very close to the same as the power ramps (within 100-200 rpm). Otherwise, you may have a bad motor that was damaged during the crash.

https://www.modalai.com/products/starling-2-max-replacement-parts?variant=49704826896688

Alex

M0162 step file : link

@JackHammer , can you please tell me which drone you have an post a picture of the motor just in case? I can point you to the correct parameters for your motor.

Alex

@Rodrigo-Betances , yes, absolutely. I will provide your name to the team.

@KLindgren , yes something seems off. Few things to try:

• try plugging the ar0144 camera into the lower slot of M0084 and using sensormodule with id 2. Double check the orientation, but the camera should face the same way (towards the voxl2 mini)
• use J6 port on the VOXL2 mini (and the corresponding camera slots will be 0 and 1)
• if you have any other camera to test, we can try just to make sure M0084 is functional. If you have another camera, let me know which one, i can help set it up.

Alex

@JackHammer

That error is weird, since 555 <= 744 <= 755. I think there is some issue with the leading 0 in the perms... Have not seen that before.

You should not have to remove the old voxl-esc package, all the files in the package will be overwritten.

I am assuming you are just making a custom version of the package? If not, you can always get the latest package from : http://voxl-packages.modalai.com/dists/qrb5165/dev/binary-arm64/

Alex

@h3robotics , you are welcome!

Actually I already tested the Hadron data flow via J8. The only change required is to use the kernel variant 1 (which is designed for M0173), but you dont actually have to have M0173 installed. Besides the kernel change, just use appropriate sensormodule drivers for Boson in slot 4 and ov64b in slot 5.

Do you have enough information from the above description to try it or do you need more details (how to install kernel, etc).

Without any other cameras there will be no limitations, but if additional cameras are used with hadron in J8, there will be some limitations. I will document soon.

Keep in mind that for the other use case (IMX412 and tracking cameras), if you are not using M0173 camera front end, you will need to use the kernel variant 0. Just one more thing to keep track of

Alex

@ROBERT-JUDD , 20-30dB is still very low, so something else is going on. Ideally, majority of satellites in open sky would be above or around 40dB. If it is at all possible, can you try disabling the 5G modem and instead just use USB connection with adb forwarding to look at voxl-portal : https://docs.modalai.com/voxl-portal-via-adb/

The reason why i asked about two antennas is because it looks like you have two antenna stacked on top of each other in your picture. Or is it just a plastic mount? . Maybe i am just not familiar with this GPS receiver you are using.

I should be getting my kit later today, so i will test it out. In my early tests i was using the original GPS module that came with Starling 2 Max and it was fine ( you can see it in the screen shots that you also shared in this thread).

Alex

@JackHammer , it should just work out of the box:

voxl-esc$ ./make_package.sh 
Package Name:  voxl-esc
version Number:  1.5.4
[sudo] password for *******:
starting building Debian Package
dpkg-deb: building package 'voxl-esc' in 'voxl-esc_1.5.4_arm64.deb'.
DONE

Note that sudo inside the script is not required, but it is there for historical reasons..

Alex