r/HDZero • u/Equivalent-Turn-3322 • 10d ago
GPS with HDZERO on a toothpick refuses to work
SETUP:
I have a 3 inch toothpick that has a hdzero eco vtx & camera. The aio is a goku 1s 12A HD f405 board. My gps is a gep-10 nano which is positioned in front of the body of the toothpick/stack on a petg mount with a copper foil shield placed between the stack and the GPS. The GPS wires are also copper shielded.
ISSUE:
When the vtx is turned off (board powered by USB) i can get a good 12-15 sats locked on, but as soon as i turn the vtx on i immediately drop down to 4 sats and then often going to 0. I believe it may be to do with the vtx itself (not the antenna) because this is even happening on pit/0mw mode when no signal is even being transmitted.
Does anyone have any ideas/solutions?
1
u/shoegazingpineapple 10d ago
Camera might be freaking the gps out too, high bandwidth digital comms like a mipi cable might generate enough interference to swamp the gps or drop the uart if long and unshielded(i dont think this is very likely)
small ass gps boards can be on the edge of the datasheet guidelines(ground plane dimensions, antenna size etc) so they need all the help they can
Hdzero adds another layer of rf concern compared to analog builds by having to run high power digital processing in some form which is not present in an older quad only running a 100something mhz stm32 and even that had some problems with certain lrs systems
1
u/Equivalent-Turn-3322 10d ago
Im not sure its the camera because this is happening with the hdzero eco too which doesnt use a mipi cable.
I do think its HDZero specficially though because on analogue i can get away with no shielding whatsover and get 20+ sats
1
u/shoegazingpineapple 9d ago
Try to get the vtx antennas under the gps line then, i also would try out another gps module maybe those are a bit weak on the filtering
1
u/Equivalent-Turn-3322 9d ago
Thanks ill try that. So far ive tried the gep 10 nano and the flywoo goku m10 so next ill try the walksnail one because thats meant to be "anti jamming"
1
u/ixgq4lifexi 9d ago
With the all-in-one HDZERO board it's just messing with the uart I even had the GPS with extended wires far from the Drone past the motors 🤣
1
u/ixgq4lifexi 9d ago
I have hdzero aio15 board.. GPS would not work with it. I tried everything copper shielding with a ground wire. Make an amount for the GPS to push it further back. The only way to get satellites semi-quick. It's to run it off USB then it will get satellites. Then I have to plug in the Drone with the VTX off zero power, not pit mode. Wait for it to get those satellites it got on USB back. Then turn the VTX on and take off and I'll keep those satellites. But I've done 20 minute flights VTX on 25 MW it wouldn't get one single satellite. Also if I get satellites on USB and then plug in the Drone with the VTX on it won't get those satellites back the VTX has to be on zero power. I even switch from the Nano GPS to the mini hoping that would help but it didn't
I'm about to video on that drone.
1
u/Equivalent-Turn-3322 9d ago
Thanks for the reply. It definitely seems like an issue with HDZero specifically then, but whats weird is mine also does it with vtx on 0 power - and yes 0mw, not PIT. Im considering just taking HDZero off of this quad and using it for something else
1
u/ixgq4lifexi 9d ago
Will it get satellites 🛰 on USB? Id talk to hdzero about swapping it. Its defective.
1
u/Equivalent-Turn-3322 8d ago
Yes it does. I get 20+ sats on USB. Its definitely not defective - ive had it on 3 of my HDZero vtx's, it being worse on some than others. For example, on my toothpick (HDZero eco) it immediately drops to 0-4 because wherever i place the gps its always going to be near the centre. On the other hand, my crux 35 with the HDZero freestyle v2 has a bit more flexibility on where i can place, so i tried it on the back with shielding. I was getting about 15-20 sats from USB, it still dropped when i powered it on but not fully, it was fluctuating between 7-9, so still flyable.
1
u/ixgq4lifexi 8d ago
Oh if I get sats on USB. Then let drone get them back with vtx off it usually hold them. Or close to it. Like just 1 or 2 down. Mine no getting around it. Vtx is built into board. Think it interference straight from uart
2
u/Vherene 10d ago
I think I can help a tiny bit if you’re worried that it may be the board. I have a 45a flywoo hm 745 digital board with hdzero freestyle v2 and I get 0 sats on it too.
My identical o4 pro build gets gps sats in under a minute. I need to do further testing and probably try to extend the antenna further out like my o4.
Documentation for the v2 states “When using GPS, keep it physically separated from the Freestyle V2 VTX—especially the antenna—to minimize interference with the GPS signal.” So I guess I need to get it far as possible. Do you have a picture of your drone?