Telemetry SIK radio

Navio / Edge Flight stack
1

See attached picture for system info.

arducopter
arducopter815×621 14.2 KB

Just bought a SIK radio and trying to connect it. Problem is that i “lose” GPS when i connect SIK radios to my navio2 and introduce the -D switch. I never get fix, and gpshdop 99,99 and satcount 0.

And i got this message in MP (wich i think i never saw before): “GPS 1: detected as u-blox at 115200 baud” even though the serial is configured to 38400

The problem seems similar to this one: Telemetry outputs other than -A & -C don't work

/etc/default/arducopter options i use tried with:

TELEM1=“-A udp:255.255.255.255:14550:bcast”
TELEM2=“-C /dev/ttyUSB0”
TELEM3=“-D /dev/ttyUSB1”
TELEM4=“-E /dev/ttyAMA0”

#Options to pass to ArduPilot
ARDUPILOT_OPTS=“$TELEM1 $TELEM2 $TELEM3 $TELEM4”

-C is the SIK radio
-D is the teensy telemetry.
-E is the reach rover

GPS stop working when i connected the SIK radio and moved the teensy from -C to -D switch.

It works as it should with only the teensy on -C switch.

Edit: Can it be as simple as a powering issue? Atm the SIK is connected directly to usb, same for the teensy.

2

Hi Daniel,

Some 433 Mhz sik radios cause interference on the GPS module, I suggest to try powering radio separately.

3

aha, i do have a 433 Mhz… Do they cause interference because they are powerd by the rpi, or is it noise on the GPS signal? Any suggestion for shielding? I have sn-cu shield laying around?

4

Will it help switching from the usb interface to the 6p connector and a cp210x?

I’ve got remnoise of 75-85 with a mean of 78, and noise at 65-70.

I tried with the sn-cu tape around the SIK radio on the drone, but didnt improve gps. Tried shielding the navio2 gps antenna with a aluminium plate, but didnt help.

What is wierd is that the reach rover unit have OK signal with its shield (10 cm plate).

Another thing i noticed was that in MP under the “messages” tab this message popped up each 30 sec “GPS 2: detected as ERB at 38400 baud”. Usually it only show once each restart.

5

Have a look there: https://community.emlid.com/t/serial-telemetry-and-external-gps-how-to-configure/8271/7

I have Navio GPS, Drotek M8N GPS and 3DR 433 telemetry radio and good GPS with telemetry antenna looking down.

Navio2DualGPS
Navio2DualGPS870×1280 290 KB

Marc

6

I have the v2 of the SIK radio with the usb interface. How did u connect the 3dr module to the navio2?

I will try pointing the antenna down.

Seems like you dont have shield on the navio2 gps. What satcound and hdop you get?

7

Hello,

3DR radio is connected via USB to the Pi (-C /dev/ttyUSB0). I have 30cm USB cables.

2nd GPS is connected to UART and I2C (compass) (-E /dev/ttyAMA0)

No shield under GPS antennas, I have 15 to 19 satellites (GPS+GLONASS) with better Sat data on M8N at the end of the mast, HDOP below 1.

Marc

8

Tried with the antenna pointing down. It’s the same. 100 hdop and 0 sats on gps1, but reach rover is good.

9

Tried this as well. No success…

might i have gotten the wrong antenna length?

10

This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.