VOXL2 + VOXL ESC FPV 4-in-1, voxl-suite 1.6.3 — battery_status never published

[nickanick]

@alex-kushleyev

Result: --id 255 isn't supported by my voxl-esc-tools (bin version 1.9) — it scans, finds IDs 0–3, then exits with ERROR: Specified ESC ID not found. Running ./voxl-esc-spin.py --id 2 --power 0 works and I do see BOARD_VOLTAGE and BOARD_CURRENT printed. So the ESC is emitting the battery telemetry message correctly.

But PX4 still never publishes battery_status:

VOXL2 M0054, voxl-suite 1.6.3, 4× M0138-1 ESCs on firmware 39, tools 1.9
BAT1_SOURCE = ESCs, VOXL_ESC_PUB_BST enabled in QGC
POWER_MANAGER=none in /etc/modalai/voxl-px4.conf (was voxlpm; changed per the comment "use none for modalai mini-esc since the esc driver handles PM" — I have no voxlpm module, the ESC is my only sensing)
px4-listener battery_status 5 → "never published", after systemctl restart voxl-px4 and a full reboot
esc_status is healthy: 4 ESCs online, esc_voltage 24.055 (6S)

Questions:

• How do I verify VOXL_ESC_PUB_BST on the flight side? px4-qshell param show VOXL_ESC_PUB_BST doesn't return anything readable in my terminal, so I can't confirm the QGC write reached the DSP.

• Does the voxl-esc driver poll ESC channel 2 for telemetry in my configuration? If its telemetry rotation depends on the motor mapping, could it be missing the one channel that sends the battery message?

• Is POWER_MANAGER=none correct for the FPV 4-in-1 (M0138), or is that comment specific to the mini ESC (M0129)?

[Eric Katzfey]

Can you provide a PX4 log file? If you cannot arm and fly the drone you can issue px4-logger on to start a log file. Then, after a few seconds, issue `px4-logger off' to close the log file.

[nickanick]

Logging start time: 0:05:12, duration: 0:19:25
Dropouts: count: 2, total duration: 0.0 s, max: 2 ms, mean: 1 ms
Info Messages:
metadata_events_sha256: 1fc3f385e1b9dac83a6f070abbb44917a26ac8128817b0a74e5155aa3da40ed0
sys_name: PX4
sys_os_name: Linux
sys_os_ver_release: 68386303
sys_toolchain: GNU GCC
sys_toolchain_ver: 7.5.0
time_ref_utc: 0
ver_data_format: 1
ver_hw: MODALAI_VOXL2
ver_sw: 3e7db37f06278a7756531d926d8bac8a71c6555f
ver_sw_release: 17694720
ver_vendor_sw_release: 33588480
Info Multiple Messages: [excluded_optional_topics: 39], [metadata_events: 1], [perf_counter_postflight: 1], [perf_counter_preflight: 1]

Name (multi id, message size in bytes) number of data points, total bytes
action_request (0, 11) 3 33
actuator_armed (0, 15) 34958 524370
actuator_controls_status_0 (0, 20) 2328 46560
actuator_motors (0, 66) 11652 769032
actuator_outputs (0, 76) 11653 885628
actuator_outputs_debug (0, 76) 328227 24945252
control_allocator_status (0, 52) 5827 303004
cpuload (0, 25) 2331 58275
cpuload (1, 25) 2331 58275
esc_status (0, 336) 232935 78266160
estimator_aid_src_baro_hgt (0, 52) 9183 477516
estimator_baro_bias (0, 40) 2326 93040
estimator_event_flags (0, 53) 1157 61321
estimator_gps_status (0, 39) 1165 45435
estimator_innovation_test_ratios (0, 152) 113035 17181320
estimator_innovation_variances (0, 152) 113042 17182384
estimator_innovations (0, 152) 113031 17180712
estimator_sensor_bias (0, 118) 2981 351758
estimator_states (0, 209) 1165 243485
estimator_status (0, 114) 5827 664278
estimator_status_flags (0, 91) 1158 105378
event (0, 40) 856 34240
failsafe_flags (0, 85) 2302 195670
failure_detector_status (0, 22) 11653 256366
home_position (0, 48) 89 4272
hover_thrust_estimate (0, 41) 11 451
input_rc (0, 71) 2330 165430
manual_control_setpoint (0, 63) 5827 367101
manual_control_switches (0, 31) 1163 36053
offboard_control_mode (0, 14) 11653 163142
parameter_update (0, 34) 3 102
rate_ctrl_status (0, 24) 5827 139848
rtl_time_estimate (0, 17) 1144 19448
sensor_accel (0, 44) 1165 51260
sensor_baro (0, 32) 1165 37280
sensor_combined (0, 48) 193109 9269232
sensor_gps (0, 124) 1165 144460
sensor_gyro (0, 44) 1165 51260
sensors_status_imu (0, 96) 5827 559392
takeoff_status (0, 13) 4 52
telemetry_status (0, 86) 1165 100190
telemetry_status (1, 86) 1165 100190
trajectory_setpoint (0, 64) 11 704
vehicle_acceleration (0, 28) 23304 652512
vehicle_air_data (0, 37) 5827 215599
vehicle_angular_velocity (0, 40) 58257 2330280
vehicle_attitude (0, 49) 23304 1141896
vehicle_attitude_setpoint (0, 54) 23304 1258416
vehicle_command_ack (0, 21) 2 42
vehicle_constraints (0, 17) 3 51
vehicle_control_mode (0, 21) 34958 734118
vehicle_gps_position (0, 124) 2330 288920
vehicle_imu (0, 56) 2330 130480
vehicle_imu_status (0, 132) 1165 153780
vehicle_land_detected (0, 20) 1165 23300
vehicle_local_position (0, 167) 11653 1946051
vehicle_local_position_setpoint (0, 64) 20 1280
vehicle_rates_setpoint (0, 33) 58258 1922514
vehicle_status (0, 66) 34958 2307228
vehicle_thrust_setpoint (0, 28) 58258 1631224
vehicle_torque_setpoint (0, 28) 58257 1631196
yaw_estimator_status (0, 105) 1165 122325

[nickanick]

Log taken with PX4 running, flight battery connected, ESCs energised, aircraft disarmed on the bench. battery_status was still unpublished during this window

[Eric Katzfey]

Can you share the log file?

[nickanick]

@eric-katzfey The log is in #7. I am getting a privilege error when I try to attach the file in Quick reply.

[Eric Katzfey]

Also share the output.txt file after running this: journalctl -u voxl-px4 -b --no-pager > output.txt

[Eric Katzfey]

Can you upload the log file to https://review.px4.io/ and then send the link?

[nickanick]

px4 log: https://review.px4.io/plot_app?log=31e428fe-d363-43c6-9cc3-236af2212533

Will post output.txt file shortly

[nickanick]

Is there I way that I can share the output.txt file with you? https://review.px4.io/ doesn't take my output.txt file

[Eric Katzfey]

The forum won't let you attach it in your reply?

[nickanick]

Error

You do not have enough privileges for this action.

Also, the text is too long so I can't copy and paste the entire log here

[Eric Katzfey]

Okay, shoot, let me see if we can get that fixed.

[Eric Katzfey]

I sent an email to the address you have linked to this account.

[nickanick]

output.txt sent

[Eric Katzfey]

File:
output.txt

[Eric Katzfey]

This is what Codex says:

The root cause is a PX4 source-enum bug, not the ESC, baud rate, or VOXL_ESC_PUB_BST.

  - The supplied parameters select BAT1_SOURCE=2, meaning “ESCs”: /home/modalai/development/log_debug/no-batt-status/
    vehicle.params:5.

  - But voxl_esc constructs its battery object as BATTERY_SOURCE_POWER_MODULE (0): src/drivers/actuators/voxl_esc/
    voxl_esc.cpp:51.

  - The battery library publishes only when the driver’s source equals BAT1_SOURCE: src/lib/battery/battery.cpp:172.
  - Therefore 0 != 2, and every battery report is silently suppressed.

  This matches all the evidence:

  - VOXL_ESC_PUB_BST=1.
  - All four M0138 channels, including current-sensing ID 2, communicate at 2 Mbaud: /home/modalai/development/log_debug/no-
    batt-status/output.txt:279.

  - The flight log contains 232,935 healthy esc_status samples but no battery_status.
  - The forum test showed ID 2 reporting BOARD_VOLTAGE and BOARD_CURRENT, proving the ESC produces the special telemetry
    packet. This is the expected M0138 behavior documented in the ModalAI ESC FAQ (https://docs.modalai.com/voxl-escs/faq/).

  The proper code fix is one line:

  _battery(1, nullptr, _battery_report_interval,
           battery_status_s::BATTERY_SOURCE_ESCS)

  As an immediate workaround with the existing binary, set BAT1_SOURCE to Power Module (0), leave POWER_MANAGER=none, restart
  voxl-px4, and check:

  px4-listener battery_status 5

  That should publish, although the resulting topic will incorrectly identify its source as a power module. The one-line source
  change is the permanent fix.

Can you try setting that parameter and see if it works?

[Eric Katzfey]

I think you need to keep BAT1_SOURCE set to 0.

[nickanick]

BAT1_SOURCE set to POWER MODULE in QGC fixed the problem.

TOPIC: battery_status
battery_status
timestamp: 332496007 (0.011529 seconds ago)
voltage_v: 23.70500
voltage_filtered_v: 23.70641
current_a: -0.08000
current_filtered_a: -0.07003
current_average_a: 15.00000
discharged_mah: 0.00138
remaining: 0.70196
scale: 1.04008
time_remaining_s: 673.87732
temperature: nan
voltage_cell_v: [0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000, 0.00000]
max_cell_voltage_delta: 0.00000
custom_faults: 0
average_power: 0.00000
available_energy: 0.00000
full_charge_capacity_wh: 0.00000
remaining_capacity_wh: 0.00000
design_capacity: 0.00000
nominal_voltage: 0.00000
capacity: 4000
cycle_count: 0
average_time_to_empty: 0
serial_number: 0
manufacture_date: 0
state_of_health: 0
max_error: 0
interface_error: 0
faults: 0
average_time_to_full: 0
over_discharge_count: 0
connected: True
cell_count: 6
source: 0
priority: 0
id: 1
is_powering_off: False
is_required: False
warning: 0
mode: 0

[nickanick]

Thanks for your help