A
We do not recommend doing apt upgrade, since we do not test this update method. If you want to update the SDK, you should do that following our SDK install instructions.
As an advanced user, you may select to update your apt sources to use dev releases (basically latest dev branches) and selectively install packages that you want to test.
The recommended SDK release for Starling 2 (Max) is 1.6.4
With that in mind, please let us know if you have any more questions about this.
Alex
OK, thanks for checking. maybe there was a typo before
Now that the main issue is resolved.. i am confused why the following test command did not work for you :
./voxl-esc-spin.py --id 255 --power 0
The screenshot you posted had the command cut off -- are you sure you used the correct command? 255 is a special value that should spin all 4 ESCs: https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/dev/voxl-esc-tools/voxl-esc-spin.py?ref_type=heads#L190
Can you check if the voxl-esc-spin.py script on your VOXL2 is the same as this file?
Thanks!
Alex
It looks like I got this working. I modified the kernel to do the following
You will need to update the kernel on your voxl2:
HW Configuration:
SW configuration
/usr/lib/camera/ -- you can get them from /usr/share/modalai/chi-cdk/ov7251 and ../boson folders:com.qti.sensormodule.ov7251_0.bin
com.qti.sensormodule.ov7251_1.bin
com.qti.sensormodule.ov7251_2.bin
com.qti.sensormodule.ov7251_3.bin
com.qti.sensormodule.boson_4.bin
voxl-camera-server.conf : https://storage.googleapis.com/modalai_public/temp/quad_ov7251_boson/voxl-camera-server-quad-ov7251-boson.conf
320x256 to 640x512 if you you have Boson640Testing
voxl-camera-server -l
...
DEBUG: Cam idx: 0, Cam slot: 0, Slave Address: 0x00E2, Sensor Id: 0x7750
DEBUG: Cam idx: 1, Cam slot: 1, Slave Address: 0x00E2, Sensor Id: 0x7750
DEBUG: Cam idx: 2, Cam slot: 2, Slave Address: 0x00E2, Sensor Id: 0x7750
DEBUG: Cam idx: 3, Cam slot: 3, Slave Address: 0x00E2, Sensor Id: 0x7750
DEBUG: Cam idx: 4, Cam slot: 4, Slave Address: 0x00D4, Sensor Id: 0x00FF
...
voxl-inspect-cam ov7251_0 ov7251_1 ov7251_2 ov7251_3 boson 
Please give it a shot and let me know if it works!
Alex
What i meant was that sometimes, depending on the frame design, the orientation of the cameras may change slightly over time. This can happen as the plastics can change shape due to exposure to heat, sunlight, humidity (depends on the plastics), bumps and crashes, etc.
Additionally, there has been some research showing that the camera + lens intrinsics change over time / temperature, especially if the lenses are made of plastic (which is the case in our old OV7251-based fisheye modules, which use plastic lenses - although we have not characterized them vs temperature).
It is possible to use stiffer and more stable materials (metals, carbon fiber) to ensure that the sensor mounting remains consistent over time.
I hope that answers your questions.
Alex
Thanks for your patience, I will try to test this today.
Here is some background..
The Mini ESC (M0129) and the FPV ESC (M0138) do not have individual channel current sensing (unlike M0134 ESC), so the individual ESC channel current is reported as 0, while each ESC channel still reports the measured voltage in the standard telemetry packet sent to the FC. For these two ESCs (M0129 and M0138), one of the ESC channels measures the total board current that flows through the ESC and sends out a second telemetry message with just voltage and total current. For M0129, the ESC channel 3 does this, and for M0138, channel 2 (0-indexed).
The telemetry messages are sent from the ESC to the FC (VOXL2) via UART and is parsed in the PX4 in voxl-esc driver. In the voxl-esc driver, if the battery status telemetry message is received from the ESC and VOXL_ESC_PUB_BST is enabled, then the driver will publish the battery_status topic with the battery voltage and current from the ESC telemetry message.
In order to do a quick test to make sure the ESC is sending out the battery status, you can do the following:
systemctl stop voxl-px4voxl-esc tools (note that these tools are not part of px4):cd /usr/share/modalai/voxl-esc-tools
./voxl-esc-spin.py --id 255 --power 0
Note that you will be running a spin test command (take off props for safety!), but the command is 0, so the motors will not spin, but you will see the telemetry from the ESC being printed in the terminal on voxl2. You will seeBOARD_VOLTAGE and BOARD_CURRENT being reported and that is coming from the extra telemetry message from the ESC. If you see this current printed, then the ESC is sending the correct information.
The argument --id 255 will tell the test script to communicate with all 4 ESC channels and the commands will be sent and telemetry requested from all 4 ESC channels (including the channel that sends back the battery status telemetry message).
Can you please check this?
voxl2:/usr/share/modalai/voxl-esc-tools$ ./voxl-esc-spin.py --id 255 --power 0
Detected Python version : 3.6.9 (default, Mar 10 2023, 16:46:00)
[GCC 8.4.0]
Found voxl-esc tools bin version: 1.9
VOXL Platform: M0054
Detected RB5 Flight, VOXL2 M0054 or M0104!
INFO: Scanning for ESC firmware: /dev/slpi-uart-2, baud: 2000000
Sending library name request: libslpi_qrb5165_io.so
Sending initialization request
INFO: ESC(s) detected on port: /dev/slpi-uart-2, baud rate: 2000000
ID : 0
Board : version 40: ModalAi 4-in-1 ESC (M0129-3)
UID : 0x2039333557555313000F0036
Firmware : version 39, hash 9c6233d6
Bootloader : version 184, hash 10bf24c8
ID : 1
Board : version 40: ModalAi 4-in-1 ESC (M0129-3)
UID : 0x2039333557555313000F0032
Firmware : version 39, hash 9c6233d6
Bootloader : version 184, hash 10bf24c8
ID : 2
Board : version 40: ModalAi 4-in-1 ESC (M0129-3)
UID : 0x2039333557555313000F0034
Firmware : version 39, hash 9c6233d6
Bootloader : version 184, hash 10bf24c8
ID : 3
Board : version 40: ModalAi 4-in-1 ESC (M0129-3)
UID : 0x2039333557555313000F0038
Firmware : version 39, hash 9c6233d6
Bootloader : version 184, hash 10bf24c8
---------------------
WARNING:
This test requires motors to spin at high speeds with
propellers attached. Please ensure that appropriate
protective equipment is being worn at all times and
that the motor and propeller are adequately isolated
from all persons.
For best results, please perform this test at the
nominal voltage for the battery used.
Type "Yes" to continue: yes
[0.015] (0) RPM: 0, PWR: 0, VOLTAGE: 0.000V, TEMPERATURE: 0.00C, CURRENT: 0.000A
[0.015] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.24C, CURRENT: 0.000A
[0.015] (2) RPM: 0, PWR: 0, VOLTAGE: 0.000V, TEMPERATURE: 0.00C, CURRENT: 0.000A
[0.015] (3) RPM: 0, PWR: 0, VOLTAGE: 0.000V, TEMPERATURE: 0.00C, CURRENT: 0.000A
[0.036] (0) RPM: 0, PWR: 0, VOLTAGE: 0.000V, TEMPERATURE: 0.00C, CURRENT: 0.000A
[0.036] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.24C, CURRENT: 0.000A
[0.036] (2) RPM: 0, PWR: 0, VOLTAGE: 16.059V, TEMPERATURE: 38.85C, CURRENT: 0.000A
[0.036] (3) RPM: 0, PWR: 0, VOLTAGE: 0.000V, TEMPERATURE: 0.00C, CURRENT: 0.000A
[0.059] (0) RPM: 0, PWR: 0, VOLTAGE: 16.039V, TEMPERATURE: 38.22C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.059] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.24C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.059] (2) RPM: 0, PWR: 0, VOLTAGE: 16.059V, TEMPERATURE: 38.85C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.059] (3) RPM: 0, PWR: 0, VOLTAGE: 16.047V, TEMPERATURE: 38.86C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.075] (0) RPM: 0, PWR: 0, VOLTAGE: 16.039V, TEMPERATURE: 38.22C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.075] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.23C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.075] (2) RPM: 0, PWR: 0, VOLTAGE: 16.065V, TEMPERATURE: 38.89C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.075] (3) RPM: 0, PWR: 0, VOLTAGE: 16.047V, TEMPERATURE: 38.86C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.047V, BOARD_CURRENT: 0.240A
[0.101] (0) RPM: 0, PWR: 0, VOLTAGE: 16.044V, TEMPERATURE: 38.19C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.101] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.23C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.101] (2) RPM: 0, PWR: 0, VOLTAGE: 16.065V, TEMPERATURE: 38.89C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.101] (3) RPM: 0, PWR: 0, VOLTAGE: 16.041V, TEMPERATURE: 38.91C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.119] (0) RPM: 0, PWR: 0, VOLTAGE: 16.044V, TEMPERATURE: 38.19C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.119] (1) RPM: 0, PWR: 0, VOLTAGE: 16.054V, TEMPERATURE: 38.23C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.119] (2) RPM: 0, PWR: 0, VOLTAGE: 16.060V, TEMPERATURE: 38.88C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.119] (3) RPM: 0, PWR: 0, VOLTAGE: 16.041V, TEMPERATURE: 38.91C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.041V, BOARD_CURRENT: 0.232A
[0.137] (0) RPM: 0, PWR: 0, VOLTAGE: 16.044V, TEMPERATURE: 38.25C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.043V, BOARD_CURRENT: 0.248A
[0.137] (1) RPM: 0, PWR: 0, VOLTAGE: 16.049V, TEMPERATURE: 38.22C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.043V, BOARD_CURRENT: 0.248A
[0.137] (2) RPM: 0, PWR: 0, VOLTAGE: 16.060V, TEMPERATURE: 38.88C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.043V, BOARD_CURRENT: 0.248A
[0.137] (3) RPM: 0, PWR: 0, VOLTAGE: 16.043V, TEMPERATURE: 38.90C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.043V, BOARD_CURRENT: 0.248A
[0.156] (0) RPM: 0, PWR: 0, VOLTAGE: 16.044V, TEMPERATURE: 38.25C, CURRENT: 0.000A, BOARD_VOLTAGE: 16.043V, BOARD_CURRENT: 0.248A
@patkirkmartin , let me double check with the team what the process for this will be and the timeline. I will get back to you soon.
Since the plan would be to provide the source to the public, it would be posted on gitlab, the feature-related discussion can happen there. We will certainly be able to help review the code and perform some testing.
Alex
Starling 2 Max is designed for 4S batteries only (two 2S Li-Ion battery packs, which are connected in series inside the vehicle). The Mini ESC, which also acts as a power source for VOXL2 inside the Starling 2 Max, is rated at least for 4S input (depending on the version of the ESC).
There are several versions of the Mini ESC to provide the users some flexibility, in particular the voltage of the VOXL2 regulator (5V for VOXL2 and 3.8V for VOXL2 Mini). Since Starling2 Max uses a VOXL2, the ESC part number will be either M0129-5 or M0129-65.
An updated (6S) version of the Mini ESC was released after the release of Starling 2 Max (new ESC part numbers: M0129-63, M0129-65). This ESC update extended the supported voltage for the ESC (not for Starling 2 Max) from 4S to 6S. The 4S version of the ESC has been phased out because the 6S version outperforms the original version even at 4S voltages (due to better Mosfets), so the 6S version is an improvement over the original 4S version of the ESC, while being fully backwards compatible.
Using the 6S-rated ESC in the 4S-rated Starling 2 Max is completely safe.
If you use the Mini ESC outside of the Starling 2 Max, you need to verify the part number / sticker on the ESC before plugging in 6S battery (M0129-63, M0129-65 only)
The ESC variants and part numbers are documented here : https://docs.modalai.com/voxl-mini-esc-datasheet/
Alex
Hello @patkirkmartin , thanks for clarifying.
Just to give you some more background and the reason for my questions: we have previously experimented with enabling DSHOT output using VOXL2 IO board and it worked during testing. However, due to lack of need and time to properly test and release, the feature was never mainlined. Also, we tested receiving the telemetry via UART only (which some DSHOT ESCs support) - had to hijack a UART port on the voxl2 io board for that.
Further developing the (bi-directional) DSHOT on the voxl2 io board is currently not on our roadmap, however if you we willing to do your own code development for the voxl2 io board, we can look into releasing the source code for it (together with the initial DSHOT output implementation).
VOXL2 itself is not capable of outputting the required DSHOT signals.
Alex
Hello @patkirkmartin,
If you are using our ESC with a new motor / prop, you need to perform a one-time ESC calibration and upload the new ESC params using the voxl-esc tools. Please see : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/master/voxl-esc-tools/calibration.md
If the motor kV is relatively low (less than 800), you may need to take a look at this as well : https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/blob/master/voxl-esc-tools/doc/low_kv_motor_tuning.md
It sounds like your de-sync is right during spinup - make sure that you are using sinusoidal spin-up and that also needs to be tweaked for best performance (only a few parameters like spin-up power and time).
If you would like to provide more details about the motor / prop / voltage, we can try to provide more guidance.
Alex
Also, please keep in mind that the OV7251 cameras have been EOL for a while and are not recommended for a new design (actually it looks like we have no stock at the moment). It seems that you already have the cameras, so we can certainly give this a try.
Hi @zaimin78 ,
First let me answer your questions about OV7251. The are two issues that need to be resolved in order to use the 4th ov7251:
I am going to check the second issue first before doing the work to re-build the kernel with updated Device Tree (wit the camera IO and CSI mappings).
Now, regarding other options.. Have you looked into our AR0144 cameras (part number M0166): https://www.modalai.com/products/msu-m0166 . It has a diagonal FOV of about 160 degrees, as stated in our camera module spec sheet. This is the primary camera type we use now for VIO applications (monochrome, global shutter). Note that these cameras do not use flex cables like the EOL camera ov7251. We are now using uCoax type of camera cables and it also means that you would need to use a different interposer to connect the cameras to voxl2. Specifically, you would use M0173 camera front end. Several users have asked about connecting 4 AR0144 cameras this way, please check the forum for the discussion.
So if you wanted to switch to the AR0144 cameras, you would most likely have to use
Please let me know which route you would like to explore.
Alex
Hello @jameskuesel ,
Sorry for the confusion about the lens change. Please see the details below.
The original lens in the IMX412 modules (M0107 and M0161) had manufacturing issues where the internal components of the lenses were loose and vibrating in flight, causing shaky video.
Due to quality / vibration issues of the original lens (part number M10000580) shipping with IMX412 (M0107 and M0161) modules, the default lens was changed to M10001028 (late 2025). However the new lens does have much narrower FOV. When purchasing the standalone camera, you have a choice of lens:
M0161 with old lens (wide) : MDK-M0161-1-07 (3.1mm EFFL, M10000580 lens)
M0161 with new lens (narrow) : MDK-M0161-1-08 (3.24 EFFL, M10001028 lens)
It seems that there maybe some discrepancy in the manufacturer stated EFFL for the new lens (3.24 vs original 3.1) because the actual FOV change is more significant than the change in the effective focal length would result in. We are looking into this.
Starling 2 and Starling 2 Max drones are currently shipping with the new lens (narrow FOV).
We do currently have stock of the old (wide) lenses that should have no issues (according to the manufacturer), however we cannot provide any guarantees for this lens due to past history of issues. If you would like to update your drone / camera with the original wide lens, please contact us and we will make it available for you to purchase (lens part number M10000580).
Alex
Sorry for being very specific.. but there are two types of telemetry you can get from DSHOT-capable ESCs.
So, do you have a requirement to use one or another.. or which specific fields in the telemetry are you looking for?
Alex
Hello @zaimin78 ,
Without any changes, you can have 1 Boson and 3 ov7251 only. I would suggest connecting Boson to J8, so that the mounting tab on the M0181 aligns withe the VOXL2 mounting hole. So you would have:
In order to connect the 4th ov7251 (it would go to J6U, via M0135), you would need a device tree change in the kernel (need a different kernel).
Also I need to double check to see if any other signal routing changes would need to be made (on M0135).. Let me get back to you soon.
Alex
@mrawding , I am sorry, but it looks like we are not going to be officially supporting Ubuntu2.0 Kernel on VOXL2, as we are working on enabling next gen hardware.. We did start the effort but it is not going to be finished for the general availability for VOXL2.
Alex
I will pass on your note about the order to our team.
Regarding DSHOT, can you please clarify which features are a must-have for your application? specifically, do you need both DSHOT control (lets say Dshot600) and DSHOT telemetry? Or UART Telemetry.. or no telemetry..
Thanks,
Alex
Hello @patkirkmartin ,
DShot could be used with VOXL2 when using Flight Core V2 as an external flight controller (stm32-based). However, Flight Core V2 is EOL.
The IO expander board (M0065) does have capable hardware to generate DSHOT signals, however, integrating and testing DShot-based ESCs is not in the scope of our team's effort.
Have you considered using a 3rd party flight controller as well as the ESC and using VOXL2 as a companion computer?
Alex
Hello @luisrzdearbulo-0 ,
Since the IMU clock stopped functioning after disassembly / re-assembly of the drone, it is likely that a small component (clock buffer) was damaged in the process. If that is the case, fixing it yourself would be extremely difficult without proper equipment and experience. Also, unfortunately, we do not offer repair services for such cases.
You have two options:
configure px4 to use IMU without the clock signal. you need to change the following two files and re-build voxl-px4:
Note that if the clock buffer chip is broken, then the second IMU will also not work (which is used for VIO), so the IMU server for the Apps Proc IMU will also need to be re-built with clock disabled : https://gitlab.com/voxl-public/voxl-sdk/services/qrb5165-imu-server/-/blob/master/server/src/icm42688.cpp?ref_type=heads#L54
voxl-imu-server and voxl-inspect-imu on voxl2)replace the VOXL2 board to get back the original functionality - I am afraid there is no other alternative.
Alex