Starling 2 Max no GPS data
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ModalAI Support,
I received a new Starling 2 Max a few days ago, and overall it's great, but I'm having a problem with GPS. Basically, the drone appears to NEVER receive any GPS signals even when left outside for long periods of time. My system info and results of px4-listener are pasted below.
This issue appears similar to these other forum discussions, where they seem to think the problem relates to EMI:
https://forum.modalai.com/topic/3879/gps-not-working-for-starling-2-max/16
I did unplug the Lepton 8-pin JST SH connector as suggested by James Strawson in the forum discussions above, but that had no effect. I also powered down the WiFI as suggested by Alex Kushleyev, but this also had no effect, although kind of a bad test for me because I couldn't put the drone outside due to USB cable length:
- pin GPIO_157 controls VBUS, which is USB power on VOXL2
- to disable, run voxl-gpio write 157 0
- to enable, run voxl-gpio write 157 1
What do you think I should do next? Is there some way to turn the power off to various subsystems via software in an attempt to figure out if and where EMI is the problem? Any other ideas?
Thanks for your help !
Starling 2 Max Outdoor GPS-denied Development Drone × 1
with Battery Pack and Controller and Case
Dual 4k & Dual Tracking & ToF (C29)
5G WiFi and Ghost Atto 2.4GHz
ECCN: EAR99, NLR
system-image: 1.8.02-M0054-14.1a-perf
kernel: #1 SMP PREEMPT Mon Nov 11 22:47:44 UTC 2024 4.19.125
hw platform: M0054
mach.var: 1.0.1
voxl-suite: 1.4.1
current IP: wlan0: 10.0.0.19
voxl2:~$ px4-listener sensor_gps
TOPIC: sensor_gps
sensor_gps
timestamp: 841732144 (0.020669 seconds ago)
timestamp_sample: 0
time_utc_usec: 0
device_id: 11272245 (Type: 0xAC, SERIAL:6 (0x00))
lat: 0
lon: 0
alt: -17000
alt_ellipsoid: 0
s_variance_m_s: 999.00006
c_variance_rad: 3.14159
eph: 4294967.50000
epv: 3796926.25000
hdop: 99.99000
vdop: 99.99000
noise_per_ms: 64
jamming_indicator: 15
vel_m_s: 0.00000
vel_n_m_s: 0.00000
vel_e_m_s: 0.00000
vel_d_m_s: 0.00000
cog_rad: 0.00000
timestamp_time_relative: 0
heading: nan
heading_offset: 0.00000
heading_accuracy: 0.00000
rtcm_injection_rate: 0.00000
automatic_gain_control: 0
fix_type: 0
jamming_state: 0
spoofing_state: 1
vel_ned_valid: False
satellites_used: 0
selected_rtcm_instance: 0voxl2:~$ px4-listener sensor_mag
TOPIC: sensor_mag
sensor_mag
timestamp: 861420482 (0.006257 seconds ago)
timestamp_sample: 861420007 (475 us before timestamp)
device_id: 527625 (Type: 0x08, I2C:1 (0x0D))
x: -0.04417
y: -0.32142
z: 0.42167
temperature: nan
error_count: 0
voxl2:~$ -
PS or maybe EMI is a red herring and the actual problem is a defective GPS antenna and/or poor electrical contact at the GPS antenna mounting pin?
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@Alex-Kushleyev : Is this something you could help me with? Thank you!
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In this case, my recommendation would be to make sure the GPS receiver is actually properly functioning. In order to do this independently from VOXL2, I usually just plug in a USB to serial adapter directly into the GPS unit and use Ublox Ucenter to interface to the GPS receiver directly.
Have you used Ublox Ucenter for testing GPS receivers before?
You may need to make a cable for the USB to serial connection to the GPS receiver. I can provide the instructions for that if you need.
The idea is to test the GPS receiver without removing from the drone, but with the whole drone being powered off and GPS receiver communicating to a laptop running Ublox Ucenter. This way, there will be no interference from the drone and satellite signal strength can be verified.
Alex
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@Alex-Kushleyev That's a great idea. I have not used Ucenter before, but I found it online and I think I could figure that part out. If you could provide instructions on how to make a cable for the USB to serial connection to the GPS receiver that would be super helpful. Sorry for the extra work and thank you!
Bob
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@Alex-Kushleyev Maybe this cable would work? https://www.amazon.com/dp/B0D9BDJBKK/
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@Alex-Kushleyev
or maybe this device: https://www.amazon.com/dp/B00LZVEQEY/
using this wiring: https://docs.modalai.com/flight-core-v2-external-sensors/#gpscompass -
@ROBERT-JUDD , Any USB-to-serial adapter should work you should probably get two different ones just in case. Just make sure the usb adapter can provide 5V and uses 3.3V logic levels.
In terms of the pinout, the following table is correct : https://docs.modalai.com/flight-core-v2-external-sensors/#gpscompass , however i wanted to clarify the TX / RX.
pin 1: 5V power from USB adapter to GPS receiver pin 2: TX out of USB adapter, RX into GPS pin 3: RX into USB adapter, TX out of GPS pin 4: I2C SCL (unused in this case) pin 5: I2C SDA (unused in this case) pin 6: GNDIf you need help with using Ucenter for basic satellite signal strength monitoring, i can make a simple video. There are many settings you can change in Ucenter, but you don't need to do much in order to do a basic satellite view.
Alex
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@Alex-Kushleyev Got it, will do and let you know. Thanks very much for your help!
Bob
