@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 , voxl-esc-calibrate.py is a script that runs a test procedure in a single motor (with propeller mounted) to calibrate the behavior of the motor / propeller. This procedure only needs to be run once if you change motor or propeller type from a default configuration. The output of this script is just 3 coeficients a1, a2, a3 which you would need to manually enter into an ESC calibration xml file and then upload the xml paramer file to the ESC. Full details about the ESC calibration (when to do it and how) can be found here : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/master/voxl-esc-tools/calibration.md?ref_type=heads

If you are using standard motors and propellers (one of standard ModalAI drones), you do not need to run this calibration procedure.

It sounds like you got it working, I believe voxl-configre-mpa took care of it. You can see what voxl-configure-mpa typically does here : https://docs.modalai.com/voxl-configure-mpa/ , which includes running voxl-esc to upload the latest firmware and params for a specific vehicle.

@psafi , before calling voxl-gpio read, you need to enable the pin by setting it to input or output. Please check voxl-gpio -h. (hint: use voxl-gpio -m / voxl-gpio mode)

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.

@tonygurney , I am assuming that you are using the ESC hardware version M0134 (you can confirm using voxl-esc scan tool.

Here is the datasheet for M0134.
https://docs.modalai.com/modal-esc-datasheet/

This ESC has an option (via installing a 0 ohm resistor) to provide 3.3V to pin 1 of J3. This is the same voltage that is used for the MCUs that run on the ESC and should be used with caution (if this voltage rail is brought down by overloading, the ESC will shut down). Please see image below that shows where 0 ohm resistor should be (carefully) installed to enable 3.3V on pin1 of J3 (marked in red)

If you actually wanted 5V (VAUX), that is available on the other side of the board via two test points at the edge of the board. This voltage rail is provided by a separate switching regulator. See the following section : https://docs.modalai.com/modal-esc-datasheet/#neopixel-led-support

If you REALLY need 5V to be present on pin1 of J3, then you can add a small wire jumper from the VAUX test point directly to the pin1 of J3 (which is marked with a white dot). This pin 1 of J3 is normally disconnected. Please only do this if you are comfortable performing this type of soldering and we cannot guarantee the results :).

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.

@Moderator said in VOXL ESC Mini 4-in-1 Current per Motor:

Is it possible to step up voltage?

Can you please clarify the question?

Mini ESC is designed for small drones ( < 500g ). The ESC has been tested to handle 15A continous at 15V input continuously (60+ seconds), but with full direct air flow from propellers. This would simulate a full throttle "punch-out" on a small FPV drone (high current, but also lots of direct airflow = cooling). Do not use this ESC if the drone needs 10-15A per channel just to hover. Use it in application where hover current per motor is less than 5A (ideally 2-3A which is very typical) and absolute maximum continuous current per motor can be 10-15A.

For example, motors used for small FPV drones often are around 1306 size (3-4S Lipo). Those motors are usually rated for up to 10-12A continous (for 30-60 seconds). Larger motors can be used as long as maximum motor current does not exceed 10-15A (still 2-3A at hover) and there is sufficient cooling.

Always check ESC board temperature during initial flights / tuning. Temperature must stay below 110C at all times (critical), typically in the range of 40-70C for most applications. The ESC will most likely fail above 125C.

Temperature of the ESC board is the limiting factor because the board is so small. Mosfets can handle a lot of current as long as they don't overheat. So the design of the drone is very important (either use low current so that temperature is not an issue or properly design air flow from propellers and/or add heat spreader to keep the ESC board temperature in normal range for higher current draw applications).

ESC provides real time temperature feedback and it can be viewed in PX4 / QGC. Additionally, the PX4 logs contain the temperature information.

It looks like your machine does not have QEMU support or is missing ARM support on your host machine. Please try instructions here : https://www.stereolabs.com/docs/docker/building-arm-container-on-x86/ (which also show you how to run ARM64 docker images on x86)

@Jetson-Nano , yes M0048 has a serial console port that is labeled in the docs (see diagram: https://docs.modalai.com/microhard-usb-carrier/) . It should work. When in doubt (if you dont see any debug prints), you can test it on a working voxl2 as well.

Alex

@Jetson-Nano , no, sorry M0151 does not have the console UART connection at all.

Alex

Hi @Peter-Lingås-0 ,

That is great to hear that you are working on a swarm project! Please feel free to ask us about any technical details and we will try to help. We generally prefer to discuss these topics here in the forum because the discussion can also be beneficial to others. If there are details about your work that you may not want to share publicly, please try to generalize them and we would be happy to discuss! It is always interesting to have discussions with users who are exploring new features like EIS because it can also help guide our development efforts based on the demand.

I will try to find out the answers regarding YOLOv8 / YOLOv11.

Alex

@paul-foley , it looks like our voxl-lepton-server is not setting the FPS field in the metadata : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-lepton-server/-/blob/master/src/publisher.c?ref_type=heads#L338 . I do see above that we do set the framerate in json info about the output pipe (cJSON_AddNumberToObject(json, "framerate", 9);) and the framerate is hardcoded to 9, since i guess all lepton sensors are running at 9fps.

I just made the change to publish the fps : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-lepton-server/-/commit/110b9cce4c021322566e46f36d6878fca55f7d26

You are using an older voxl SDK, so installing latest nightly package (from http://voxl-packages.modalai.com/dists/qrb5165/dev/binary-arm64/ will probably not work). So you probably need to take the source of the version you are running now (1.3.3 : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-lepton-server/-/tree/v1.3.3?ref_type=tags) and apply the same change in the source code and build it.

Since i just pushed to dev branch, a new version of leptop server should appear in our package repo tomorrow, and you can download and try it. it might work, but your SDK is 2 major versions down from where we are now (1.4.x vs 1.6.x), so you may want to just build the patched version 1.3.3 :

git clone https://gitlab.com/voxl-public/voxl-sdk/services/voxl-lepton-server.git
cd voxl-lepton-server
git checkout v1.3.3

#make the change in publisher.c to include fps ...
...

#start voxl-cross docker (you can download it in our downloads section: https://developer.modalai.com/asset) 
docker run -it --rm -v `pwd`:/opt/code -w /opt/code voxl-cross:V4.6 bash

./install_build_deps.sh qrb5165 sdk-1.4
./build.sh qrb5165
./make_package.sh

#then, outside docker, deploy the new package to voxl2 via adb
./deploy_to_voxl.sh

Please let me know if this works for you!

Alex

Hi @jon ,

Can you please confirm a few items:

• you are not using a modalai ESC and the voxl2_io board is controlling ESCs usign channels 1-4?
• are you able to actuate the channel 5 using QGC actuator test?
• are you able to map an RC switch to control channel 5 using your RC? is that a viable option for you?

I understand your issue, it seems there is some disconnect between the high level API to send the VehicleCommand and the low level voxl2_io driver in px4 running on DSP. If the actuator test and rc mapping is working then, the issue is going to be at a higher level, potentially the VehicleCommand message not getting through from the CPU side of px4 to the DSP. We will check on that.

Alex

@Vansh-Aggarwal , sorry for the delay in response. Can you please specify which exact tracking cameras you have and which camera adapters / cables you might already have?

Alex

@dstylesunf , sorry for the delay. In order to buy a M0202 + M0194 + cables kit for Hadron, please send us an request : https://www.modalai.com/pages/contact-us

Same for any replacement parts for stinger you might need, they are not up in the shop yet.

Alex

@SKA , just to clarify, if you disable EIS, then undistortion is disabled, you will see fisheye image. If EIS is enabled, the output will be undistorted (zoomed in a bit). Part of EIS figures out the minimum zoom level such that the undistorted image is maximized (no black pixels at the edges), so if EIS is enabled and you set misp_zoom to 1.0, the image will appear slightly zoomed in because it is undistorted (and parts of the image are no longer visible, what used to be the corners).

if you set misp_zoom to 1.0 and eis is disabled, you will see the image that is not zoomed in. If your misp width and height aspect ratio differs from the raw preview aspect ratio, then misp will crop the top+bottom (usually), to get the correct aspect ratio. For example, if your raw preview size is 4040x3040 and your misp output is 1920x1080, then misp will first crop the top and bottom of the raw image to get the 16:9 aspect ratio and then resize the image to 1920x1080 (well actually all the steps are happening at the same time, not sequentially).

I have to ask, how do you know that your image is zoomed in and not original? btw since you have the small video stream enabled, you can look at that image (hires_small_color) to see if the zoom level is the same - this is coming from the ISP and it should also crop + resize to your resolution for small video stream you have selected (you can make the small video resolution the same as misp output resolution and compare images, they should look identical zoom-wise)

Alex

@john_t , I think DFS is tricky on drones because it requires a very good calibration (intrinsics, extrinsics) and the extrinsics cannot change, which is hard to guarantee on the drone. Alternatively, a robust system would be needed that will continuously recalibrate extrinsics over time. This may be the reason why stereo is not easily to use with consistent success on drones.

ToF works well indoors with range up to 4-6 meters, but outdoors the sunlight will severely degrade the performance. Some technical details are available here : https://docs.modalai.com/M0178/

Alex

@SKA , you are probably looking at the wrong stream, since you have small video enabled, which does not use misp. Use hires_misp_ streams