ModalAI Forum

I'm using a VOXL2 (m0054) running SDK 1.6.5 in a custom airframe, and I wanted to confirm somethings about the calibration process. In the past, I thought I was able to use voxl-calibrate-imu to calibrate the IMU and gyros in lieu of running the calibration through PX4. However, recently that doesn't seem to work anymore.

Based on what I've been able to find on the forum, the IMU used by PX4 is separate from the IMU used by ModalAI apps and isn't calibrated by voxl-calibrate-imu. Can you confirm that in order to prepare a vehicle for flight, I'd need to calibrate the imu_apps IMU using voxl-calibrate-imu and then also calibrate the PX4 IMU through QGC (and ignore the pop-up about unreliable calibration over WiFi)?

Also, for other VOXL IMU related commands like voxl-inspect-imu and voxl-calibrate-imu-temp, are these only for imu_apps (i.e. not for the PX4 imu), or is there a way to get these to show information from the PX4 IMU?

Where can I get the most up-to-date firmware for the VOXL2 IO breakout board? The board we recently bought still seems to have outdated firmware on it, and it isn't working with an updated VOXL2. The VOXL2 is running voxl-suite version 1.5.0. When I run voxl-px4 in daemon mode (voxl-px4 -d) I'm seeing error messages about an invalid firmware version from voxl2_io (see attached)

I tried updating to the firmware available on the public downloads page mentioned in the documentation and get a similar error

I've managed get things to work using the firmware here: https://forum.modalai.com/topic/2446/connecting-i2c-device-on-voxl2/20, however the post seems to imply that it's a test firmware. Where else would I be able to obtain the current VOXL2 IO board firmware? Or should I carry on using the firmware from the post?

@Eric-Katzfey Okay, thanks again for all your help!

@Eric-Katzfey Thank you for the help! Setting en_external_ap_timesync in voxl-mavlink-server.conf to false allows the timesync messages to go through. I didn't need to disable voxl-vision-hub in order to get the timestamp messages.

For future reference, what does the should the fcu_url be to connect from the onboard (Linux side) to the PX4 through the GCS connection? Or is it possible at all? I get errors saying that the address is already in use whenever I'm trying to use port 14550 from the onboard computer. Things work fine running mavros from a different computer or by keeping voxl-vision-hub active.

@Eric-Katzfey I did some more troubleshooting on my own, and I think I've tracked the problem down to voxl-mavlink-server. If I disable voxl-mavlink-server using "systemctl stop voxl-mavlink-server" and start mavros pointing to the UDP ports that voxl-mavlink-server connects to (14556/14557), then I get properly timestamped messages. Looking at the estimator status (px4-listener estimator_status), EKF2 is happily accepting the mocap data.

Running voxl-mavlink-server directly in the terminal with the "-t" parameter to debug timesync protocol handling, it seems like voxl-mavlink-server is intercepting the timesync messages that mavros is trying to send to PX4. This results in MAVROS not being able to estimate the offset to the PX4 clock and stamp it's messages correctly.

I've tried running voxl-vision-hub and voxl-mavlink-server directly in terminal with debug print statements to see what is going on, and it seems like there's an issue with the timesync requests coming from the onboard pipe as opposed to the autopilot. I've attached some samples below:

Standard Timesync request from autopilot

from APob  ID: 111
to APob    ID: 111
timesync: now-ts1 =-2360.9ms
to APob    ID: 111
sending our own ts request at 8420226379035
from APob  ID: 111
ap ms ahead of voxl:     2361.1ms

Timesync request from MAVROS

onboard  pipe  ID: 111 compid: 240
to APob    ID: 111
from APob  ID: 111
unknown timesync request ts1 = 1744850282998741263 tc1 = 8422617042000 last_voxl_time_sent = 8420226379035

There's no final response sending the timesync message (ID:111) back through the onboard pipe to MAVROS.

Looking at voxl-vision-hub and filtering out for just timesync messages

There's only messages to the autopilot, but none coming back. I think that's why our MAVROS timestamps are off; it is not syncing with PX4 correctly.

Can you help me figure out how to get the MAVROS timesync requests sent properly so that MAVROS receives the server-side response?

@Eric-Katzfey So I see that the firmware is supposed to apply the estimated offset to the timestamp to make sure that the timestamps align. Is there a way to change or correct the timesync system if it isn't correct (as seems to be the case here)? Or at least check the timesync status?

And regarding the mocap position estimate, is the local position estimator module you are referring to this LPE estimator referred to in the PX4 documentation or is it a different module specifically for EKF2? I'm just trying to get an understanding of what is going on, especially since it seems like in the documentation from PX4, there's a choice to either use the LPE or EKF2 with slightly different parameters and workflows for each.

Regardless, what method would you recommend for getting mocap position data sent to PX4? Is there a service in VOXL that we could try to route the position data through from ROS that would work better?

@Eric-Katzfey I don't think that there's anything that should be interfering with MAVROS, though I'm not familiar enough with the VOXL services to know if there's one I need to be worried about. I've attached a screen capture of "voxl-inspect-services" along with the voxl-vision-hub.conf, voxl-px4.conf, voxl-mavlink-server.conf files in case you spot anything that's amiss with them.

voxl-vision-hub.conf:

{
	"config_file_version":	1,
	"en_localhost_mavlink_udp":	true,
	"localhost_udp_port_number":	14551,
	"en_vio":	false,
	"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":	"off",
	"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,
	"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_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_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":	true,
			"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":	true,
			"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":	true,
			"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":	true,
			"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
		}]
}

voxl-px4.conf

AIRFRAME=MULTICOPTER
GPS=NONE
RC=M0065_SBUS
ESC=VOXL2_IO_PWM_ESC
POWER_MANAGER=VOXLPM
AIRSPEED_SENSOR=NONE
DISTANCE_SENSOR=NONE
OSD=DISABLE
DAEMON_MODE=ENABLE
SENSOR_CAL=ACTUAL
ARTIFACT_MODE=DISABLE
EXTRA_STEPS=()

voxl-mavlink-server.conf

{
	"primary_static_gcs_ip":	"192.168.8.10",
	"secondary_static_gcs_ip":	"192.168.8.11",
	"onboard_port_to_autopilot":	14556,
	"onboard_port_from_autopilot":	14557,
	"gcs_port_to_autopilot":	14558,
	"gcs_port_from_autopilot":	14559,
	"en_external_uart_ap":	false,
	"autopilot_uart_bus":	1,
	"autopilot_uart_baudrate":	921600,
	"autopilot_mission_delay_start":	-1,
	"autopilot_mission_delay_sound":	false,
	"autopilot_mission_notif_dur":	0.1,
	"en_external_ap_timesync":	1,
	"en_external_ap_heartbeat":	1,
	"udp_mtu":	0,
	"gcs_timeout_s":	4.5
}

@Eric-Katzfey It's set to 11 (Horiztonal Postion, Vertical Position, Yaw)

Hello,

We are trying to incorporate motion capture data into the VOXL2 (m0054) in order to fly in position mode. We are using ROS 1 and taking motion capture data, processing and stamping the data onboard the VOXL and publishing it to /mavros/vision_pose/pose. We are seeing data streaming on /mavros/vision_pose/pose when echoing with rostopic echo /mavros/vision_pose/pose. Also when we use px4-listener to listen to vehicle_visual_odometry on the px4 side, we are also seeing data. However, in QGC, it reports no valid local position estimate (in position mode), and EKF2 does not appear to be using the vision data at all. We're not sure what is going wrong where EKF2 is not accepting the information. We've tried following for mocap data on the PX4 documentation along with following along with this forum post.

We have a suspicion that the timestamps might be messed up between MAVROS and PX4 but are unsure. We are seeing weird values when we look at the uORB messages using px4-listener (sample attached below).

Do you have any idea what we might be doing wrong?

VOXL Suite Version: 1.4.1

Sample Vehicle Visual Odometry uORB with report saying "timestamp_sample" in the future relative to timestamp

EKF2 Status