GPS not working

Andre Moura

@Eric-Katzfey The sentinel is as it was on arrival 2 days ago, no hardware changes.

We ran px4-shell gps status and got:

voxl2:~$ px4-qshell gps status
INFO  [qshell] Send cmd: 'gps status'
INFO  [qshell] qshell return value timestamp: 801929670, local time: 801931434

Eric Katzfey

@andremoura Okay, that's not very useful. Let's try something else. First of all can you post the contents of the file /etc/systemd/system/voxl-px4.service? Then, stop the service from autostarting voxl-px4 with the commands systemctl disable voxl-px4 and sync. Then reboot the drone. When you adb back in to the drone you can run voxl-inspect-services to verify that voxl-px4 isn't running. Then you can start voxl-px4 manually from the command line with voxl-px4 and then post all of the output from that.

Andre Moura

@Eric-Katzfey After manually stopping and starting the voxl-px4 service, it has been working on startup.
Very strange, since when I first noticed the GPS issue, the service was running from startup but not receiving any data (as seen on my console print). However, now it seems to work every time we shut down and power on the drone.

Thank you for your help!

Eric Katzfey

@andremoura Okay, that's unexpected. Oh well, at least it is working now! Let me know if it starts to give trouble again.

Andre Moura

@Eric-Katzfey Unfortunately the GPS is not working as expected. Yesterday we were momentarily able to get between 9-12 satellites, which I think is a little low. With that number of satellites, we were not able to get GPS lock on the drone, QGC displayed an error related to GPS accuracy too low. Even after allowing to arm without GPS lock and flying at about 15 m, the number of satellites didn't change and we couldn't even put the drone in position mode, because of not being GPS locked.

What we did to be able to even get those satellites was systemctl disable voxl-px4 , systemctl disable voxl-mavlink-server, rebooted the drone and, in two different ssh shells, ran both services manually.

Today, using this approach, I'm not even able to get any satellites at all. All the following tests were done with the ekf2_outdoor_gps_mag.params configuration file from your Gitlab.

The output from voxl-px4 was:

voxl2:~$ voxl-px4
Found DSP signature file
INFO  [px4] mlockall() enabled. PX4's virtual address space is locked into RAM.
INFO  [px4] assuming working directory is rootfs, no symlinks needed.

______  __   __    ___ 
| ___ \ \ \ / /   /   |
| |_/ /  \ V /   / /| |
|  __/   /   \  / /_| |
| |     / /^\ \ \___  |
\_|     \/   \/     |_/

px4 starting.

INFO  [px4] Calling startup script: /bin/sh /etc/modalai/voxl-px4.config 0
Running on M0054
INFO  [muorb] SLPI: Creating qurt thread hpwork

INFO  [muorb] SLPI: Successfully created px4 task PX4_hpwork with tid 82
INFO  [muorb] SLPI: Creating qurt thread lpwork

INFO  [muorb] SLPI: Successfully created px4 task PX4_lpwork with tid 81
INFO  [muorb] SLPI: Creating qurt thread wkr_hrt

INFO  [muorb] SLPI: Successfully created px4 task PX4_wkr_hrt with tid 80
INFO  [muorb] SLPI: Creating qurt thread client_sync_thread

INFO  [muorb] SLPI: Successfully created px4 task PX4_client_sync_thread with tid 79
INFO  [muorb] SLPI: Creating qurt thread wq_manager

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_manager with tid 78
INFO  [muorb] SLPI: Creating qurt thread qshell

INFO  [muorb] SLPI: Successfully created px4 task PX4_qshell with tid 77
INFO  [qshell] Send cmd: 'icm42688p start -s'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: icm42688p start -s
INFO  [muorb] SLPI: Creating qurt thread wq_SPI1

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_SPI1 with tid 76
INFO  [muorb] SLPI: *** SPI Device ID 0x26000a 2490378
INFO  [uorb] Advertising remote topic sensor_accel
INFO  [uorb] Marking DeviceNode(parameter_server_set_used_request) as advertised in process_remote_topic
INFO  [muorb] SLPI: Marking DeviceNode(parameter_server_set_used_response) as advertised in process_remote_to
INFO  [uorb] Advertising remote topic sensor_gyro
INFO  [uorb] Advertising remote topic imu_server
INFO  [muorb] SLPI: on SPI bus 1
INFO  [muorb] SLPI: icm42688p #0 on SPI bus 1 (devid=0x0)
INFO  [muorb] SLPI: 

INFO  [muorb] SLPI: Ok executing command: icm42688p start -s
INFO  [muorb] SLPI: Sending qshell retval with timestamp 23323798, current timestamp 23323799
INFO  [uorb] Advertising remote topic qshell_retval
INFO  [qshell] qshell return value timestamp: 23323798, local time: 23327958
INFO  [muorb] SLPI: Marking DeviceNode(parameter_client_reset_request) as advertised in process_remote_topic
ERROR [muorb] SLPI: Cannot reset all parameters on client side
INFO  [uorb] Marking DeviceNode(parameter_client_reset_response) as advertised in process_remote_topic
INFO  [muorb] SLPI: Advertising remote topic parameter_update
INFO  [muorb] SLPI: Marking DeviceNode(parameter_client_set_value_request) as advertised in process_remote_to
INFO  [uorb] Marking DeviceNode(parameter_client_set_value_response) as advertised in process_remote_topic
INFO  [logger] logger started (mode=all)
Starting Holybro magnetometer
INFO  [qshell] Send cmd: 'ist8310 start -R 10 -X -b 1'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: ist8310 start -R 10 -X -b 1
INFO  [muorb] SLPI: Creating qurt thread wq_I2C1

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_I2C1 with tid 75
INFO  [muorb] SLPI: *** I2C Device ID 0x60e09 396809
INFO  [muorb] SLPI: ist8310 #0 on I2C bus 1 (external)

INFO  [muorb] SLPI: Ok executing command: ist8310 start -R 10 -X -b 1
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26405496, current timestamp 26405497
INFO  [qshell] qshell return value timestamp: 26405496, local time: 26406391
Starting Holybro LED driver
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: rgbled_ncp5623c start -X -b 1 -f 400 -a 56
INFO  [muorb] SLPI: *** I2C Device ID 0x7b3809 8075273
INFO  [qshell] Send cmd: 'rgbled_ncp5623c start -X -b 1 -f 400 -a 56'
INFO  [muorb] SLPI: rgbled_ncp5623c #0 on I2C bus 1 (external)

INFO  [muorb] SLPI: Ok executing command: rgbled_ncp5623c start -X -b 1 -f 400 -a 56
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26445017, current timestamp 26445018
INFO  [qshell] qshell return value timestamp: 26445017, local time: 26445673
INFO  [qshell] Send cmd: 'icp10100 start -I -b 5'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: icp10100 start -I -b 5
INFO  [muorb] SLPI: Creating qurt thread wq_I2C5

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_I2C5 with tid 74
INFO  [muorb] SLPI: *** I2C Device ID 0x9c6329 10249001
INFO  [muorb] SLPI: probe probe succeeded. data = 0x1 0x48
INFO  [muorb] SLPI: icp10100 #0 on I2C bus 5

INFO  [muorb] SLPI: Ok executing command: icp10100 start -I -b 5
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26486020, current timestamp 26486021
INFO  [qshell] qshell return value timestamp: 26486020, local time: 26487682
INFO  [uorb] Advertising remote topic sensor_mag
INFO  [qshell] Send cmd: 'modalai_esc start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: modalai_esc start
INFO  [muorb] SLPI: Creating qurt thread wq_hp_default

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_hp_default with tid 73
INFO  [uorb] Advertising remote topic sensor_baro
INFO  [uorb] Advertising remote topic test_motor
INFO  [muorb] SLPI: Ok executing command: modalai_esc start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26546800, current timestamp 26546801
INFO  [muorb] SLPI: Opened UART ESC device
INFO  [qshell] qshell return value timestamp: 26546800, local time: 26548152
INFO  [qshell] Send cmd: 'mixer load /dev/uart_esc quad_x.main.mix'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: mixer load /dev/uart_esc quad_x.main.mix
INFO  [muorb] SLPI: Creating qurt thread wq_rate_ctrl

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_rate_ctrl with tid 71
INFO  [muorb] SLPI: Ok executing command: mixer load /dev/uart_esc quad_x.main.mix
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26609932, current timestamp 26609933
INFO  [qshell] qshell return value timestamp: 26609932, local time: 26611050
INFO  [uorb] Advertising remote topic actuator_outputs
INFO  [uorb] Advertising remote topic multirotor_motor_limits
INFO  [qshell] Send cmd: 'voxlpm start -X -b 2'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: voxlpm start -X -b 2
INFO  [muorb] SLPI: Creating qurt thread wq_I2C2

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_I2C2 with tid 4169
INFO  [muorb] SLPI: *** I2C Device ID 0x784411 7881745
INFO  [uorb] Advertising remote topic battery_status
INFO  [muorb] SLPI: voxlpm #0 on I2C bus 2 (external)

INFO  [muorb] SLPI: Ok executing command: voxlpm start -X -b 2
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26674290, current timestamp 26674291
INFO  [qshell] qshell return value timestamp: 26674290, local time: 26675325
INFO  [uorb] Advertising remote topic power_monitor
Starting Holybro GPS
INFO  [qshell] Send cmd: 'gps start -d 7 -b 115200'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: gps start -d 7 -b 115200
INFO  [muorb] SLPI: Creating qurt thread gps

INFO  [muorb] SLPI: Successfully created px4 task PX4_gps with tid 70
INFO  [muorb] SLPI: Ok executing command: gps start -d 7 -b 115200
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26712883, current timestamp 26712884
INFO  [qshell] qshell return value timestamp: 26712883, local time: 26713903
INFO  [qshell] Send cmd: 'px4io detect'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: px4io detect
INFO  [muorb] SLPI: serial port fd 2
ERROR [muorb] SLPI: px4io read failed
ERROR [muorb] SLPI: px4io io_reg_get(0,0,1): data error -5
ERROR [muorb] SLPI: IO not installed
ERROR [muorb] SLPI: Detection attempt 2 failed
ERROR [muorb] SLPI: Detection attempt 1 failed
ERROR [muorb] SLPI: Detection attempt 0 failed
ERROR [muorb] SLPI: Failed to execute command: px4io detect
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26777758, current timestamp 26777759
INFO  [qshell] cmd returned with: -17
INFO  [qshell] qshell return value timestamp: 26777758, local time: 26778378
ERROR [qshell] Command failed
M0065 not detected, starting Spektrum RC driver
INFO  [qshell] Send cmd: 'spektrum_rc start -d 8'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: spektrum_rc start -d 8
INFO  [muorb] SLPI: Creating qurt thread spektrum_rc_main

INFO  [muorb] SLPI: Successfully created px4 task PX4_spektrum_rc_main with tid 67
INFO  [muorb] SLPI: Ok executing command: spektrum_rc start -d 8
INFO  [muorb] SLPI: Sending qshell retval with timestamp 26822566, current timestamp 26822566
INFO  [qshell] qshell return value timestamp: 26822566, local time: 26823292
INFO  [qshell] Send cmd: 'sensors start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: sensors start
INFO  [muorb] SLPI: Creating qurt thread wq_nav_and_controllers

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_nav_and_controllers with tid 66
INFO  [muorb] SLPI: Ok executing command: sensors start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 27885493, current timestamp 27885494
INFO  [uorb] Advertising remote topic vehicle_angular_acceleration
INFO  [uorb] Advertising remote topic vehicle_angular_velocity
INFO  [qshell] qshell return value timestamp: 27885493, local time: 27890054
INFO  [muorb] SLPI: Creating qurt thread wq_INS0

INFO  [muorb] SLPI: Successfully created px4 task PX4_wq_INS0 with tid 65
INFO  [uorb] Advertising remote topic vehicle_imu
INFO  [uorb] Advertising remote topic vehicle_imu_status
INFO  [uorb] Advertising remote topic sensors_status_imu
INFO  [uorb] Advertising remote topic vehicle_acceleration
INFO  [uorb] Advertising remote topic vehicle_air_data
INFO  [uorb] Advertising remote topic sensor_selection
INFO  [uorb] Advertising remote topic sensor_combined
INFO  [qshell] Send cmd: 'ekf2 start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: ekf2 start
INFO  [muorb] SLPI: Ok executing command: ekf2 start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28080230, current timestamp 28080231
INFO  [qshell] qshell return value timestamp: 28080230, local time: 28081490
INFO  [uorb] Advertising remote topic ekf2_timestamps
INFO  [qshell] Send cmd: 'mc_pos_control start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: mc_pos_control start
INFO  [muorb] SLPI: Ok executing command: mc_pos_control start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28141872, current timestamp 28141873
INFO  [qshell] qshell return value timestamp: 28141872, local time: 28143606
INFO  [qshell] Send cmd: 'mc_att_control start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: mc_att_control start
INFO  [muorb] SLPI: Ok executing command: mc_att_control start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28193889, current timestamp 28193890
INFO  [qshell] qshell return value timestamp: 28193889, local time: 28194908
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: mc_rate_control start
INFO  [qshell] Send cmd: 'mc_rate_control start'
INFO  [muorb] SLPI: Ok executing command: mc_rate_control start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28277320, current timestamp 28277321
INFO  [qshell] qshell return value timestamp: 28277320, local time: 28277781
INFO  [qshell] Send cmd: 'mc_hover_thrust_estimator start'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: mc_hover_thrust_estimator start
INFO  [muorb] SLPI: Ok executing command: mc_hover_thrust_estimator start
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28316740, current timestamp 28316741
INFO  [qshell] qshell return value timestamp: 28316740, local time: 28317757
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [qshell] Send cmd: 'land_detector start multicopter'
INFO  [muorb] SLPI: qshell gotten: land_detector start multicopter
INFO  [muorb] SLPI: Ok executing command: land_detector start multicopter
INFO  [muorb] SLPI: Sending qshell retval with timestamp 28355231, current timestamp 28355232
INFO  [qshell] qshell return value timestamp: 28355231, local time: 28356012
INFO  [uorb] Advertising remote topic vehicle_land_detected
INFO  [muorb] SLPI: 28570980: reset position to last known position
INFO  [muorb] SLPI: 28570980: reset velocity to zero
INFO  [uorb] Advertising remote topic vehicle_local_position
INFO  [uorb] Advertising remote topic vehicle_odometry
INFO  [uorb] Advertising remote topic estimator_states
INFO  [uorb] Advertising remote topic estimator_status
INFO  [uorb] Advertising remote topic estimator_status_flags
INFO  [uorb] Advertising remote topic estimator_innovations
INFO  [uorb] Advertising remote topic estimator_innovation_test_ratios
INFO  [uorb] Advertising remote topic estimator_innovation_variances
INFO  [dataman] Unknown restart, data manager file '/data/px4/dataman' size is 11798680 bytes
INFO  [muorb] SLPI: Advertising remote topic position_setpoint_triplet
INFO  [commander] LED: open /dev/led0 failed (22)
INFO  [muorb] SLPI: Advertising remote topic led_control
INFO  [muorb] SLPI: Advertising remote topic tune_control
INFO  [PreFlightCheck] Failed EKF health preflight check while waiting for filter to settle
INFO  [muorb] SLPI: Advertising remote topic vehicle_control_mode
INFO  [muorb] SLPI: Advertising remote topic vehicle_status
INFO  [muorb] SLPI: Advertising remote topic actuator_armed
INFO  [uorb] Advertising remote topic rate_ctrl_status
INFO  [uorb] Advertising remote topic actuator_controls_0
INFO  [muorb] SLPI: Advertising remote topic commander_state
INFO  [muorb] SLPI: Advertising remote topic vehicle_status_flags
INFO  [muorb] SLPI: Advertising remote topic vehicle_command
INFO  [commander] Handling Commander command 176
INFO  [muorb] SLPI: Advertising remote topic vehicle_command_ack
INFO  [mavlink] mode: Onboard, data rate: 100000 B/s on udp port 14556 remote port 14557
INFO  [muorb] SLPI: Marking DeviceNode(vehicle_command) as advertised in process_remote_topic
INFO  [uorb] Advertising remote topic estimator_sensor_bias
INFO  [px4] Startup script returned successfully
pxh> INFO  [muorb] SLPI: Advertising remote topic telemetry_status
INFO  [muorb] SLPI: 34702200: EKF aligned, (baro hgt, IMU buf: 11, OBS buf: 8)
INFO  [uorb] Advertising remote topic vehicle_attitude
INFO  [uorb] Advertising remote topic vehicle_attitude_setpoint
INFO  [uorb] Advertising remote topic vehicle_rates_setpoint

Inside the pxh console, we ran the gps status command and got:

INFO  [gps] not running
Command 'gps' failed, returned -1.

I find this strange since when we ran the voxl-px4 service it had the start command for the gps. Since gps was not running, I decided to test again the gps start by doing gps stop and then gps start -d 7 -b 115200, that appeared on the output of ```voxl-px4``. The console output was:

ERROR [gps] GPS: failed to open serial port: 7 err: 2

We also tried the same with qshell.
qshell gps status outputted:

pxh> qshell gps status
INFO  [qshell] Send cmd: 'gps status'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: gps status
INFO  [muorb] SLPI: Main GPS
INFO  [muorb] SLPI: protocol: UBX
INFO  [muorb] SLPI: status: NOT OK, port: 6, baudrate: 115200
INFO  [muorb] SLPI: sat info: disabled
INFO  [muorb] SLPI: rate reading: 		     0 B/s
INFO  [muorb] SLPI: Ok executing command: gps status
INFO  [muorb] SLPI: Sending qshell retval with timestamp 318302556, current timestamp 318302557
INFO  [qshell] qshell return value timestamp: 318302556, local time: 318308860

We also tried to stop and run it again with qshell gps stop and qshell gps start.

After this, the output of qshell gps status was:

pxh> qshell gps status
INFO  [qshell] Send cmd: 'gps status'
INFO  [muorb] SLPI: Marking DeviceNode(qshell_req) as advertised in process_remote_topic
INFO  [muorb] SLPI: qshell gotten: gps status
INFO  [muorb] SLPI: Main GPS
INFO  [muorb] SLPI: protocol: UBX
INFO  [muorb] SLPI: status: OK, port: 6, baudrate: 115200
INFO  [muorb] SLPI: sat info: disabled
INFO  [muorb] SLPI: rate reading: 		   695 B/s
INFO  [muorb] SLPI: rate position: 		  5.00 Hz
INFO  [muorb] SLPI: rate velocity: 		  5.00 Hz
INFO  [muorb] SLPI: rate publication:		  5.00 Hz
INFO  [muorb] SLPI: rate RTCM injection:	  0.00 Hz
INFO  [muorb] SLPI:  sensor_gps_s

INFO  [muorb] SLPI: 	timestamp: 405957015  (0.197956 seconds ago)

INFO  [muorb] SLPI: 	time_utc_usec: 0

INFO  [muorb] SLPI: 	lat: 0

INFO  [muorb] SLPI: 	lon: 0

INFO  [muorb] SLPI: 	alt: -17000

INFO  [muorb] SLPI: 	alt_ellipsoid: 0

INFO  [muorb] SLPI: 	s_variance_m_s: 1000.0001

INFO  [muorb] SLPI: 	c_variance_rad: 3.1416

INFO  [muorb] SLPI: 	eph: 4294967.5000

INFO  [muorb] SLPI: 	epv: 3772217.5000

INFO  [muorb] SLPI: 	hdop: 99.9900

INFO  [muorb] SLPI: 	vdop: 99.9900

INFO  [muorb] SLPI: 	noise_per_ms: 93

INFO  [muorb] SLPI: 	jamming_indicator: 30

INFO  [muorb] SLPI: 	vel_m_s: 0.0000

INFO  [muorb] SLPI: 	vel_n_m_s: 0.0000

INFO  [muorb] SLPI: 	vel_e_m_s: 0.0000

INFO  [muorb] SLPI: 	vel_d_m_s: 0.0000

INFO  [muorb] SLPI: 	cog_rad: 0.0000

INFO  [muorb] SLPI: 	timestamp_time_relative: 0

INFO  [muorb] SLPI: 	heading: -nan

INFO  [muorb] SLPI: 	heading_offset: 0.0000

INFO  [muorb] SLPI: 	fix_type: 0

INFO  [muorb] SLPI: 	jamming_state: 0

INFO  [muorb] SLPI: 	vel_ned_valid: False

INFO  [muorb] SLPI: 	satellites_used: 0

INFO  [muorb] SLPI: Ok executing command: gps status
INFO  [muorb] SLPI: Sending qshell retval with timestamp 406155973, current timestamp 406155974
INFO  [qshell] qshell return value timestamp: 406155973, local time: 406158054

Any ideia of what the problem could be?

I also noticed the following errors on the voxl-px4 output:

ERROR [muorb] SLPI: px4io read failed
ERROR [muorb] SLPI: px4io io_reg_get(0,0,1): data error -5
ERROR [muorb] SLPI: IO not installed
ERROR [muorb] SLPI: Detection attempt 2 failed
ERROR [muorb] SLPI: Detection attempt 1 failed
ERROR [muorb] SLPI: Detection attempt 0 failed
ERROR [muorb] SLPI: Failed to execute command: px4io detect

Is this normal?

Thank you.

Eric Katzfey

@andremoura Yes, the errors related to px4io detection are expected since you do not have a px4io unit attached to the drone. And yes, you have to interact with things on the DSP (where the GPS driver runs) with qshell as you already figured out. Do you have any other Sentinel drones that you can compare against? Or other types of drones with GPS to compare against? When you are able to get 9 to 12 satellites what does qshell gps status show? It does appear to be wired up correctly as sometimes it is obviously communicating with the GPS unit.

Eric Katzfey

@andremoura It looks like there are at least 2 different issues here. One is that when you do see it working it has poor performance and doesn't get a lock. That is why I wanted to compare against other drones or other GPS units. If other units are working fine and this one isn't then maybe it's a faulty unit. If they all have poor performance then maybe it's something about the test location.

Eric Katzfey

@andremoura The other issue appears to be that you don't always get the driver to communicate with the GPS unit on startup. The start line in /etc/modalai/voxl-px4.config is qshell gps start -d 7 -b 115200. When you did qshell gps stop and then qshell gps start was it started with qshell gps start -d 7 -b 115200 or just qshell gps start?

Andre Moura

@Eric-Katzfey We don't have any other Sentinel drones. We have other drones with GPS, that detect at least the same or higher number of satellites but they all are able to GPS lock.

When we had that number of satellites, the qshell gps status seemed ok with number of satellites, latitude and longitude, but we aren't able to replicate that test right now because of bad weather conditions.

Andre Moura

@Eric-Katzfey I will test the Sentinel drone on a new better location next week, if weather gets better, and I will get back to you.

Andre Moura

@Eric-Katzfey GPS mostly hasn't beeen working on startup again.

We started it with qshell gps start, but we also tested qshell gps start -d 7 -b 115200. Both commands only worked a few times, we are not able to consistently start the GPS, having to stop and start again the service a few times before it works.

Eric Katzfey

@andremoura Is the LED on top of the unit (multicolor LED) coming on?

Andre Moura

@Eric-Katzfey said in GPS not working:

@andremoura Is the LED on top of the unit (multicolor LED) coming on?

Yes, every time voxl-px4 is running.

Eric Katzfey

@andremoura Okay, good. Holybro changed some of the components in their unit at one point and if that LED wasn't coming on it could indicate that it was one of the older units. But since it is on that indicates to me that it is the correct version of the Holybro unit.

Andre Moura

@Eric-Katzfey Ok, new find! It seems that when voxl-px4 runs, the GPS service isn't able to start immediately, but if we wait a for a bit and start it manually, it works.

Seems like something isn't ready to start immediately after voxl-px4.

Eric Katzfey

@andremoura Interesting! Okay, how do you accomplish that? Do you mean you are stopping the service and then starting voxl-px4 later manually or you are leaving voxl-px4 service enabled but commenting out the gps start line in /etc/modalai/voxl-px4.config?

Andre Moura

@Eric-Katzfey We are stopping the GPS service manually (qshell gps stop) and then starting it later manually (qshell gps start), not the voxl-px4.

Do you want us to do the same test with commenting the gps start line in /etc/modalai/voxl-px4.config?

Eric Katzfey

@andremoura Actually, can you try removing the -d 7 -b 115200 from the gps start line in /etc/modalai/voxl-px4.config and see if that changes anything? Thanks for trying all this stuff out!

Andre Moura

@Eric-Katzfey Hello, today I tested removing -d 7 -b 115200 from /etc/modalai/voxl-px4.config and it seems like the GPS service is working correctly on startup. I'm still going to test if I can get more fixed satellites and GPS lock on a new location with more open space and then get back to this post with more information.

Andre Moura

@Eric-Katzfey On the new location, we were able to get GPS lock after fixing 12 satellites, which allowed for take-off. During flight we reached 19 satellites at one point. Getting GPS lock with this sensor is a bit challenging, our previous location didn't have that many obstructions, but everything seems to be working.