ModalAI Forum

Hii @Eric-Katzfey ,
I am trying to install the voxl-mainline-px4 package on a VOXL2 Mini (M0104) running VOXL SDK 1.6.3.

The installation fails due to a dependency on a newer version of libfc-sensor.

System information

• Hardware: VOXL2 Mini (M0104)
• SDK: 1.6.3
• Installed library:

libfc-sensor 1.0.9

Command used

sudo dpkg -i voxl-mainline-px4_1.17.0-1.0.2-202602240859_arm64.deb

Error

voxl-mainline-px4 depends on libfc-sensor (>= 1.0.10); however:
Version of libfc-sensor on system is 1.0.9.

Package metadata

Running dpkg -s voxl-mainline-px4 shows:

Depends:
libfc-sensor (>= 1.0.10),
voxl-px4-params (>= 0.3.10),
voxl2-system-image (>= 1.5.4),
modalai-slpi (>= 1.1.16)

Repository check

The SDK repository only provides:

libfc-sensor 1.0.9

apt-cache policy libfc-sensor
Installed: 1.0.9
Candidate: 1.0.9

Question

How to solve this issue???

Thanks.

Hi ModalAI Team,

I am working with a VOXL2 Mini test fixture (TF-M0104) and trying to integrate a VL53L1X ToF rangefinder with PX4 for altitude hold / height-above-ground estimation.

My goal is for PX4 EKF2 to fuse the rangefinder data so that the drone can use the sensor for altitude estimation (dist_bottom / HAGL).

Sensor configuration:

/etc/modalai/voxl-rangefinder-server.conf

{
"i2c_bus": 0,
"vl53l1x_timing_budget_ms": 50,
"id_for_mavlink": 0,
"sensors": [{
"enabled": true,
"sensor_id": 0,
"type": "TOF_VL53L1X",
"fov_deg": 15,
"range_max_m": 3,
"location_wrt_body": [0,0,0],
"direction_wrt_body": [0,0,1],
"is_on_mux": false
}]
}
PX4 parameters
EKF2_HGT_REF = 2
EKF2_RNG_CTRL = 1
EKF2_RNG_A_HMAX = 11.5 ft
SENS_EN_VL53L1X : 1
Sensor data received in PX4
px4-listener distance_sensor

current_distance: 0.62
signal_quality: 100
orientation: 25

So PX4 is receiving the rangefinder data correctly.

However, when I check:

voxl2-mini-test-fixture (TF-M0104):/etc/modalai$ px4-listener vehicle_local_position

TOPIC: vehicle_local_position
vehicle_local_position
timestamp: 1258315007 (0.002534 seconds ago)
timestamp_sample: 1258313140 (1867 us before timestamp)
ref_timestamp: 0
ref_lat: nan
ref_lon: nan
x: -58.15529
y: -29.38294
z: -43.47373
delta_xy: [-8.27161, 3.48610]
delta_z: 0.00000
vx: -5.77044
vy: -8.23159
vz: 0.09748
z_deriv: 0.09754
delta_vxy: [-0.89175, 1.40937]
delta_vz: 0.65828
ax: 1.33592
ay: -1.74908
az: 0.01860
heading: 2.12604
delta_heading: 1.62808
ref_alt: nan
dist_bottom: 0.10000
eph: 0.61074
epv: 0.20321
evh: 0.41361
evv: 0.11114
vxy_max: inf
vz_max: inf
hagl_min: inf
hagl_max: inf
xy_valid: True
z_valid: True
v_xy_valid: True
v_z_valid: True
xy_reset_counter: 32
z_reset_counter: 6
vxy_reset_counter: 37
vz_reset_counter: 26
heading_reset_counter: 17
heading_good_for_control: False
xy_global: False
z_global: False
dist_bottom_valid: False
dist_bottom_sensor_bitfield: 0
dead_reckoning: True

which means EKF2 is not fusing the rangefinder measurement.

Am I missing any configuration steps to enable rangefinder fusion for altitude hold on VOXL2?

Hii @Eric-Katzfey we wanted to confirm whether ModalAI has a recommended parameter set or procedure to achieve a smooth transition between outdoor and indoor flight on VOXL 2 mini ??

What is the recommended workflow to switch between usb0 and wlan0 ????
as when i tried to use voxl-wifi in station mode ,it configured succesfully.
But current IP is still:
voxl2-mini-test-fixture (TF-M0104):~$ voxl-my-ip
usb0: 192.168.7.2
voxl2-mini-test-fixture (TF-M0104):~$

Thankyou so much @Alex-Kushleyev
This setup solves my use case where Wi-Fi is not available. Thanks for the support — looking forward to the scripted version in the future.

Best regards,
Sarika

Hii @Alex-Kushleyev , Thankyou so much for your time...
Previously, I said 4 cameras are detected and working properly only with M0135 interposer not with M0084 flex cable and the screenshot above is taken while using M0084 flex cables that's why only 3 cameras are detected out of 4 and hires is not streaming.

@Alex-Kushleyev

@Alex-Kushleyev Hi ,

Thanks for the explanation.
I tested this on VOXL2 Mini and can confirm the following observations:
With kernel 2.0.0, all 4 cameras are detected correctly, but only with the specific hardware configuration below.

Working hardware configuration:

J6 → M0135

JL: HiRes

JU: Tracking

J7 → M0135

JL: Tracking

JU: PMD-ToF

In this configuration, all four cameras are detected successfully.

Additional observation regarding M0084 flex cables(with kernel 2.0.0):
I have two different M0084 flex cables, and I’m seeing :

With one M0084 cable, the HiRes camera is detected, but no high-resolution stream appears in voxl-portal.

With the other M0084 cable, the HiRes camera is not detected properly. The voxl-camera-server log shows:

Starting Camera: hires (id #0)
ERROR: Camera 0 failed to find supported stream config: 1024x768
WARNING: Failed to start cam hires due to invalid resolution
WARNING: assuming cam is missing and trying to compensate

@modaltb Hii, is there any update on this?

@Alex-Kushleyev Hii, Kindly look at the hardware configuration .
I am only able to detect 2 cameras out of 4 cameras .
Hires and one out of 2 tracking are not detected.

@James-Strawson Hii , I am also getting the same issue . Kindly look at the following details . I have defined tof in my extrinsics.conf file as given below:
parent: body
child: tof
T_child_wrt_parent: 0.070 0.024 -0.029
RPY_parent_to_child: 0.0 90.0 90.0
R_child_to_parent: 0.000 -0.000 1.000
1.000 0.000 -0.000
-0.000 1.000 0.000
when i run voxl-vision-hub -s i got the following
slice 0 dist none back
slice 1 dist none
slice 2 dist none
slice 3 dist none
slice 4 dist none
slice 5 dist none
slice 6 dist none
slice 7 dist none
slice 8 dist none
slice 9 dist none left
slice 10 dist none
slice 11 dist none
slice 12 dist none
slice 13 dist none
slice 14 dist none
slice 15 dist none
slice 16 dist none
slice 17 dist none
slice 18 dist none forward
slice 19 dist none
slice 20 dist none
slice 21 dist none
slice 22 dist none
slice 23 dist none
slice 24 dist none
slice 25 dist none
slice 26 dist none
slice 27 dist none right
slice 28 dist none
and in my vision-hub-conf file i have the folloeing set up:
"en_vio": true,
"vio_pipe": "qvio",
"secondary_vio_pipe": "ov",
"vfc_vio_pipe": "ov",
"en_reset_vio_if_initialized_inverted": true,
"vio_warmup_s": 3,
"send_odom_while_failed": true,
"horizon_cal_tolerance": 0.5,
"en_hitl": false,
"offboard_mode": "figure_eight",
"follow_tag_id": 0,
"figure_eight_move_home": true,
"robot_radius": 0.300000011920929,
"collision_sampling_dt": 0.1,
"max_lookahead_distance": 1,
"backtrack_seconds": 60,
"backtrack_rc_chan": 8,
"backtrack_rc_thresh": 1500,
"wps_move_home": true,
"wps_stride": 0,
"wps_timeout": 0,
"wps_damp": 1,
"wps_vfc_mission": true,
"wps_vfc_mission_loop": false,
"wps_vfc_mission_to_ramp": 25,
"wps_vfc_mission_to_kp": 0.10000000149011612,
"wps_vfc_mission_cruise_speed": 1,
"en_tag_fixed_frame": false,
"fixed_frame_filter_len": 5,
"en_transform_mavlink_pos_setpoints_from_fixed_frame": false,
"vfc_rate": 100,
"vfc_rc_chan_min": 980,
"vfc_rc_chan_max": 2020,
"vfc_thrust_ch": 3,
"vfc_roll_ch": 1,
"vfc_pitch_ch": 2,
"vfc_yaw_ch": 4,
"vfc_submode_ch": 6,
"vfc_alt_mode_rc_min": 0,
"vfc_alt_mode_rc_max": 0,
"vfc_flow_mode_rc_min": 0,
"vfc_flow_mode_rc_max": 0,
"vfc_hybrid_flow_mode_rc_min": 0,
"vfc_hybrid_flow_mode_rc_max": 0,
"vfc_position_mode_rc_min": 0,
"vfc_position_mode_rc_max": 2100,
"vfc_traj_mode_rc_min": 0,
"vfc_traj_mode_rc_max": 0,
"vfc_yaw_deadband": 30,
"vfc_vxy_deadband": 50,
"vfc_vz_deadband": 150,
"vfc_min_thrust": 0,
"vfc_max_thrust": 0.800000011920929,
"vfc_tilt_max": 0.43599998950958252,
"vfc_yaw_rate_max": 3,
"vfc_thrust_hover": 0.5,
"vfc_vz_max": 1,
"vfc_kp_z": 5.2899999618530273,
"vfc_kd_z": 5.9800000190734863,
"vfc_vxy_max": 3,
"vfc_kp_xy": 0.63999998569488525,
"vfc_kd_xy": 2.559999942779541,
"vfc_kp_z_vio": 5.2899999618530273,
"vfc_kd_z_vio": 5.9800000190734863,
"vfc_kp_xy_vio": 3.2400000095367432,
"vfc_kd_xy_vio": 3.9600000381469727,
"vfc_w_filt_xy_vio": 10,
"vfc_w_filt_xy_flow": 3,
"vfc_vel_ff_factor_vio": 0.899999976158142,
"vfc_xy_acc_limit_vio": 2.5,
"vfc_max_z_delta": 3,
"vfc_att_transition_time": 0.5,
"vfc_stick_move_threshold": 30,
"vfc_flow_transition_time": 1,
"vfc_q_min": 10,
"vfc_points_min": 7,
"vfc_en_submode_announcement": 1,
"vfc_disable_fallback": false,
"vfc_traj_csv": "/data/voxl-vision-hub/traj.csv",
"en_voa": true,
"voa_upper_bound_m": -0.15000000596046448,
"voa_lower_bound_m": 0.15000000596046448,
"voa_memory_s": 1,
"voa_max_pc_per_fusion": 100,
"voa_pie_max_dist_m": 20,
"voa_pie_min_dist_m": 0.25,
"voa_pie_under_trim_m": 1,
"voa_pie_threshold": 3,
"voa_send_rate_hz": 20,
"voa_pie_slices": 36,
"voa_pie_bin_depth_m": 0.15000000596046448,
"voa_inputs": [{
"enabled": false,
"type": "point_cloud",
"input_pipe": "dfs_point_cloud",
"frame": "stereo_l",
"max_depth": 8,
"min_depth": 0.300000011920929,
"cell_size": 0.079999998211860657,
"threshold": 4,
"x_fov_deg": 68,
"y_fov_deg": 56,
"conf_cutoff": 0
}, {
"enabled": false,
"type": "point_cloud",
"input_pipe": "stereo_front_pc",
"frame": "stereo_front_l",
"max_depth": 8,
"min_depth": 0.300000011920929,
"cell_size": 0.079999998211860657,
"threshold": 4,
"x_fov_deg": 68,
"y_fov_deg": 56,
"conf_cutoff": 0
}, {
"enabled": false,
"type": "point_cloud",
"input_pipe": "stereo_rear_pc",
"frame": "stereo_rear_l",
"max_depth": 8,
"min_depth": 0.300000011920929,
"cell_size": 0.079999998211860657,
"threshold": 4,
"x_fov_deg": 68,
"y_fov_deg": 56,
"conf_cutoff": 0
}, {
"enabled": true,
"type": "tof",
"input_pipe": "tof",
"frame": "tof",
"max_depth": 6,
"min_depth": 0.15000000596046448,
"cell_size": 0.079999998211860657,
"threshold": 3,
"x_fov_deg": 106.5,
"y_fov_deg": 85.0999984741211,
"conf_cutoff": 125
}, {
"enabled": false,
"type": "rangefinder",
"input_pipe": "rangefinders",
"frame": "body",
"max_depth": 8,
"min_depth": 0.300000011920929,
"cell_size": 0.079999998211860657,
"threshold": 4,
"x_fov_deg": 68,
"y_fov_deg": 56,
"conf_cutoff": 0
}],
"voa_voa_memory_s": 1
}

@Sarika-Sharma and I also wanna tell you my goal i.e. stable indoor flight without GPS

Hello @Alex-Kushleyev
Thank you for getting back to me.

Yes, I already have the above cameras.I am attaching image of the PMD TOF image sensor along with the adapters that were included, so you can confirm exactly which configuration I have.

I would also be very open to your suggestions regarding updates or improvements to the camera selection. Please feel free to recommend better options based on your experience.

Looking forward to your guidance.

Hello Team, I’m working with a VOXL2 Mini and would like guidance on the correct hardware configuration (cables and ports) for the following camera setup:

Cameras

1. 2× M0014 (OV7251 tracking cameras)

2. 1× M0169 (PMD ToF camera)

3. 1× M0024 (IMX214 high-resolution camera)

Available accessories

1. M0084 flex cables

2. M0135 interface board

Could you please confirm the correct physical connection / port mapping for this setup on VOXL2 Mini?

@Sarika-Sharma Now TOF is detected. I have choosed pmd-tof instead of pmd-tof-liow2.
But please give solution for the following problem.
When I used J7 according to the following configuration
Hardware Setup
M0104 Connector Interposer Sensor HW ID
J7 M0135 JL Tracking (M0014 ) 2
J7 M0135 JU Hires (M0025-2 ) 3
OR
J7 M0135 JL Hires (M0025-2 ) 2
J7 M0135 JU Tracking (M0014 ) 3

ONLY , The camera which is connected to JL is working either tracking or hires.
Cameras connected to JU is not working.
When i run voxl-camera-server it gives this
WARNING: cam tracking (id 1) does not seem to be alive

------ voxl-camera-server: Started 1 of 2 cameras

------ voxl-camera-server: Camera server is now running
OR
When i run voxl-camera-server it gives this
WARNING: cam hires (id 1) does not seem to be alive

------ voxl-camera-server: Started 1 of 2 cameras

------ voxl-camera-server: Camera server is now running/home/idr/Downloads/WhatsApp Image 2025-12-26 at 5.31.01 PM.jpeg

@Alex-Kushleyev @Luca-Zanatta I am also facing the same issue, can you please tell how to solve resolution problem.
I have tried to manually add preview width and preview height in vim /etc/modalai/voxl-camera-server.conf But when i run voxl-camera-server it still gives previous resolution 240*1557 and hence pmd-tof is not detected.

@Sarika-Sharma Kindly resolve this issue also https://forum.modalai.com/topic/4952/pmd-tof-not-detected-on-voxl2?_=1766730439331.

@Eric-Katzfey Thank you.

Hello ModalAI Team,

I am working with VOXL2 / VOXL2 Mini and PMD ToF V2 (M0169), and I am facing an issue where the PMD ToF camera is not detected/started by voxl-camera-server.

System details

Platform: VOXL2

System Image: 1.7.4

PMD Module: M0169 (PMD ToF)

Use case: Tracking + ToF + HiRes

Hardware connection (Option 1)
VOXL2 → M0076 → M0074 extender → M0169 (external regulated 5V supplied) → ToF

External 5V is provided to M0169.

Camera configuration

Cameras enabled: PMD ToF + IMX214 (HiRes) + OV7251 (Tracking)

IMX214 and OV7251 start correctly, but not pmd-tof

kindly look at the screenshots.
/home/idr/Pictures/Screenshots/Screenshot from 2025-12-25 17-40-44.png
/home/idr/Pictures/Screenshots/Screenshot from 2025-12-25 17-40-54.png
/home/idr/Pictures/Screenshots/Screenshot from 2025-12-25 17-41-05.png

/home/idr/Downloads/WhatsApp Image 2025-12-25 at 6.00.04 PM.jpeg

@Eric-Katzfey If you would be so kind as to tell how can i specify a different port to connect to at the GCS for each drone?