VOXL ESC FPV 4-in-1 with Built-in Power Module (MDK-M0138) Issues

[jbiscan21]

Hello.

I am using the VOXL2 with the FPV ESC and experiencing some issues. I can detect/scan and spin the motors at different rpms using the CLI tool on the voxl, but I cannot get the motors to throttle up in response to my RC transmitter. I verified that my rc throttle channel and actuator outputs are increasing as I raise throttle in mavlink inspector. I also tried calibrating the escs as well but that did not fix the issue. I also checked the VOXL ESC params such as min and max rpm (3000 - 30000 rpm). The motors are emax 2807 1300kvs.

[Eric Katzfey]

What software versions are you using? Can you please create a PX4 log and share that via https://logs.px4.io/? Since logging normally doesn't start until you arm the drone you can force the logger to start and stop. For example, from the adb shell you can use px4-logger on to start a log and then px4-logger off to stop the log. Can you also paste the outputs from the detect / scan? Also review this other post: https://forum.modalai.com/topic/4833/throttle-doesnt-work/7

[jbiscan21]

@Eric-Katzfey Attached below. I misspoke, it appears detect fails.

Here is the link: PX4 Logs

voxl2-test-fixture (TF-M0054):/$ voxl-version 
────────────────────────────────────────────────────────────────────────────────
system-image: 1.8.06-M0054-14.1a-perf
kernel:       #1 SMP PREEMPT Wed Oct 22 04:13:18 UTC 2025 4.19.125
────────────────────────────────────────────────────────────────────────────────
hw platform:  M0054
mach.var:     1.0.1
SKU:          TF-M0054-4-V1-C11
────────────────────────────────────────────────────────────────────────────────
voxl-suite:   1.6.3
────────────────────────────────────────────────────────────────────────────────
Packages:
Repo:  http://voxl-packages.modalai.com/ ./dists/qrb5165/sdk-1.6/binary-arm64/
Last Updated: 2026-08-06 19:57:23
List:
libfc-sensor                   1.0.9
libmodal-cv                    0.6.0
libmodal-exposure              0.1.4
libmodal-flow                  1.0.3
libmodal-journal               0.2.7
libmodal-json                  0.4.8
libmodal-pipe                  2.14.11
libqrb5165-io                  0.6.3
libvoxl-cci-direct             0.3.3
libvoxl-codec                  0.0.2
libvoxl-cutils                 0.1.6
modalai-slpi                   1.2.2
mv-voxl                        0.1-r0
qrb5165-bind                   0.1-r0
qrb5165-dfs-server             0.2.0
qrb5165-mini-tof-server        0.2.2
qrb5165-rangefinder-server     0.1.6
qrb5165-slpi-test-sig          01-r0
qrb5165-tflite                 2.17.2
voxl-bind-spektrum             0.1.1
voxl-camera-calibration        0.6.1
voxl-camera-server             2.2.19
voxl-ceres-solver              2:2.0.0-2
voxl-configurator              1.1.5
voxl-cpu-monitor               0.7.7
voxl-docker-support            1.3.1
voxl-elrs                      1.1.0
voxl-esc                       1.6.3
voxl-esptool                   0.2.0
voxl-feature-tracker           0.5.2
voxl-flow-server               0.3.6
voxl-gphoto2-server            0.0.10
voxl-imu-server                2.0.1
voxl-io-server                 0.0.8
voxl-jpeg-turbo                2.1.3-7
voxl-lepton-server             1.3.3
voxl-lepton-tracker            0.0.4
voxl-libgeographic             1.0.0
voxl-libgphoto2                0.0.4
voxl-libuvc                    1.0.7
voxl-logger                    0.6.1
voxl-mavcam-manager            0.6.0
voxl-mavlink                   0.1.6
voxl-mavlink-server            1.4.14
voxl-modem                     1.2.3
voxl-mongoose                  7.19.0
voxl-mpa-to-ros                0.3.9
voxl-mpa-tools                 1.5.6
voxl-nano-tracker              0.1.7
voxl-open-vins-server          0.6.0
voxl-opencv                    4.5.5-3
voxl-osd                       0.3.8
voxl-portal                    0.8.7
voxl-px4                       1.14.0-2.0.133
voxl-px4-params                0.9.0
voxl-qvio-server               1.2.3
voxl-remote-id                 0.0.9
voxl-reset-slpi                0.0.1
voxl-state-estimator           0.0.6
voxl-streamer                  0.8.0
voxl-suite                     1.6.3
voxl-tag-detector              0.1.0
voxl-tflite-server             0.5.1
voxl-utils                     2.0.2
voxl-uvc-server                0.1.7
voxl-vision-hub                1.9.21
voxl-vtx                       2.0.2
voxl-wavemux                   0.0.3
voxl2-io                       0.0.3
voxl2-security-hardening-utls  1.0-r0
voxl2-system-image             1.8.06-r0
voxl2-wlan                     1.0-r0
────────────────────────────────────────────────────────────────────────────────

voxl2-test-fixture (TF-M0054):/$ voxl-esc scan
enabling bridge
detected voxl-px4 is enabled
Removed /etc/systemd/system/multi-user.target.wants/voxl-px4.service.
detected voxl-px4 is running, stopping it now
Sending kill slpi command!
bridge enabled
Detected Python version : 3.6.9 (default, May 22 2025, 20:54:22) 
[GCC 8.4.0]
Found voxl-esc tools bin version: 1.10
VOXL Platform: QRB5165
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, protocol: firmware


INFO: ESC Information:
INFO: ---------------------
	ID         : 0
	Board      : version 42: ModalAi 4-in-1 ESC (M0138-1)
	UID        : 0x203837304848570400440022
	Firmware   : version  39.25, hash a58f5f6f
	Bootloader : version    187, hash aad89d63

	ID         : 1
	Board      : version 42: ModalAi 4-in-1 ESC (M0138-1)
	UID        : 0x203837304848570300310055
	Firmware   : version  39.25, hash a58f5f6f
	Bootloader : version    187, hash aad89d63

	ID         : 2
	Board      : version 42: ModalAi 4-in-1 ESC (M0138-1)
	UID        : 0x2038373048485705003A003F
	Firmware   : version  39.25, hash a58f5f6f
	Bootloader : version    187, hash aad89d63

	ID         : 3
	Board      : version 42: ModalAi 4-in-1 ESC (M0138-1)
	UID        : 0x203837304848570400440025
	Firmware   : version  39.25, hash a58f5f6f
	Bootloader : version    187, hash aad89d63

---------------------
successfully pinged ESCs
disabling bridge
Sending kill slpi command!
re-enabling voxl-px4
Created symlink /etc/systemd/system/multi-user.target.wants/voxl-px4.service → /etc/systemd/system/voxl-px4.service.
restarting voxl-px4
bridge disabled
voxl2-test-fixture (TF-M0054):/$ voxl-esc detect 
enabling bridge
detected voxl-px4 is enabled
Removed /etc/systemd/system/multi-user.target.wants/voxl-px4.service.
detected voxl-px4 is running, stopping it now
Sending kill slpi command!
bridge enabled
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
Couldn't configure flight_controller sensor
ERROR:   fc_sensor_initialize failed
ERROR:   Failed to initialize slpi
ERROR:   Encountered error while initializing bus 12
[ERROR] No ESCs detected
disabling bridge
Sending kill slpi command!
re-enabling voxl-px4
Created symlink /etc/systemd/system/multi-user.target.wants/voxl-px4.service → /etc/systemd/system/voxl-px4.service.
restarting voxl-px4
bridge disabled
EXITING VOXL-ESC WITH ERROR
voxl2-test-fixture (TF-M0054):/$