Voxl2 + M0041 RevB Battery Monitor on Arducopter

Dan Jennings

Hi I'm using the M0041 board to power our voxl2 running ardupilot and having difficulty configuring the battery monitor. I found this post but we do not have the BATT_I2C_BUS parameter to set.

When checking voxl-inspect-battery, we only get the headers, no data. Voxl-vision-hub is running.

voxl-version
────────────────────────────────────────────────────────────────────────────────
system-image: 1.8.04-M0054-14.1a-perf
kernel:       #1 SMP PREEMPT Mon Mar 24 22:31:58 UTC 2025 4.19.125
────────────────────────────────────────────────────────────────────────────────
hw platform:  M0054
mach.var:     1.0.1
SKU:          MCCA-M0054-C11-T0-M0-X0
────────────────────────────────────────────────────────────────────────────────
voxl-suite:   1.5.0
────────────────────────────────────────────────────────────────────────────────
Packages:
Repo:  http://voxl-packages.modalai.com/ ./dists/qrb5165/sdk-1.5/binary-arm64/
Last Updated: 2026-03-18 01:43:20
List:
libfc-sensor                1.0.7
libmodal-cv                 0.5.18
libmodal-exposure           0.1.4
libmodal-journal            0.2.6
libmodal-json               0.4.7
libmodal-pipe               2.13.2
libqrb5165-io               0.5.0
libvoxl-cci-direct          0.3.3
libvoxl-cutils              0.1.5
modalai-slpi                1.2.0
mv-voxl                     0.1-r0
qrb5165-bind                0.1-r0
qrb5165-dfs-server          0.2.0
qrb5165-imu-server          1.1.3
qrb5165-mini-tof-server     0.2.2
qrb5165-rangefinder-server  0.1.5
qrb5165-slpi-test-sig       01-r0
qrb5165-system-tweaks       0.3.6
qrb5165-tflite              2.8.0-2
voxl-ardupilot              4.8.0-325875bb
voxl-bind-spektrum          0.1.1
voxl-camera-calibration     0.6.0
voxl-camera-server          2.2.4
voxl-ceres-solver           2:1.14.0-10
voxl-configurator           1.0.2
voxl-cpu-monitor            0.6.0
voxl-docker-support         1.3.1
voxl-elrs                   0.4.7
voxl-esc                    1.5.4
voxl-feature-tracker        0.5.2
voxl-flow-server            0.3.6
voxl-gphoto2-server         0.0.10
voxl-joystick-server        0.0.6
voxl-jpeg-turbo             2.1.3-7
voxl-lepton-server          1.3.3
voxl-lepton-tracker         0.0.4
voxl-libgphoto2             0.0.4
voxl-libuvc                 1.0.7
voxl-logger                 0.5.3
voxl-mavcam-manager         0.6.0
voxl-mavlink                0.1.5
voxl-mavlink-server         1.4.9
voxl-modem                  1.1.8
voxl-mongoose               7.7.0-2
voxl-mpa-to-ros             0.3.9
voxl-mpa-tools              1.4.0
voxl-open-vins              0.4.19
voxl-open-vins-server       0.3.12
voxl-opencv                 4.5.5-3
voxl-osd                    0.1.8
voxl-portal                 0.7.11
voxl-px4                    1.14.0-2.0.105
voxl-px4-params             0.7.5
voxl-qvio-server            1.2.0
voxl-remote-id              0.0.9
voxl-reset-slpi             0.0.1
voxl-state-estimator        0.0.5
voxl-streamer               0.7.5
voxl-suite                  1.5.0
voxl-tag-detector           0.0.5
voxl-tflite-server          0.4.1
voxl-utils                  1.4.8
voxl-uvc-server             0.1.7
voxl-vision-hub             1.8.23
voxl-vtx                    1.4.7
voxl-wavemux                0.0.1
voxl2-io                    0.0.3
voxl2-system-image          1.8.04-r0
voxl2-wlan                  1.0-r0

Eric Katzfey

@Dan-Jennings Which arducopter build are you using?

Eric Katzfey

@Dan-Jennings Rather than use voxl-inspect-battery have you tried QGC or Mission Planner or Mav Proxy?

Dan Jennings

@Eric-Katzfey
We're on voxl-ardupilot 4.8.0-325875bb

I've been connecting through mission planner, but have not been able to get any battery data. Looked through mavlink inspector and there is no battery_status topic.

Eric Katzfey

@Dan-Jennings I'd try our voxl-inspect-mavlink application. Check voxl-inspect-mavlink mavlink_onboard and voxl-inspect-mavlink mavlink_to_gcs and see if battery_status appears at all. I just loaded voxl-ardupilot_ArduCopter_4.8.0-94b27fd3_arm64.deb on my voxl2 with our standard APM and I see battery status in QGroundControl and with voxl-inspect-mavlink mavlink_to_gcs. Also, can you upgrade to VOXL SDK 1.6.x?

Dan Jennings

@Eric-Katzfey

I don't see any battery_status message

Dan Jennings

@Eric-Katzfey
We will look into updating the sdk, but that's always a fair bit of work.

Eric Katzfey

@Dan-Jennings I'm also guessing that the driver may not be detecting the hardware so is not able to get the data for the battery_status. Have you tried swapping some other hardware to see if the problem is associated with a particular unit?

Dan Jennings

@Eric-Katzfey I finally had an opportunity to try a different power board but we still do not have any battery_status topic. We will look at updating the SDK but don't want to derail our CV development doing so. I'd prefer to find a solution without having to do that.

Eric Katzfey

@Dan-Jennings Honestly, I don't think updating the SDK version will help this issue. But, we highly encourage everyone to be on the latest SDK, regardless, since that's where you'll get the latest fixes and features. And it's how you'll get the best support from us. but in this case I don't think a newer SDK will get you the battery_status. It's probably a hardware issue or a parameter issue. You swapped boards and that didn't help. What about the cable? Those 4 wire cables are notoriously fragile. Can you swap it out and see if that helps? The other item is parameters. You saw that other post about setting BATT_MONITOR to 21 and BATT_I2C_BUS to 1. If you don't see the BATT_I2C_BUS parameter then it must mean that BATT_MONITOR hasn't been set to 21. Make sure it is set to 21, then reboot, then you should see the BATT_I2C_BUS parameter. Then set it to 1, reboot, then you should see correct battery_status.