Hoverfly Hoverfly GPS saved my ship! I nearly had a Heart Attack! 2013 Demo Reel.

[mspencer1]

Ok, next silly question...

I have the same firmware running on the GPS and the HFP board. I have been able to do the temperature, accelerometer and temperature calibrations successfully.
I have been able to do the compass calibration successfully outside and the correct checkboxes work at the right time in the main tab, eg: AH, AL, PH, RTH. On the GPS tab the map comes up successfully and the satelittes show a number of satillites connected. The compass calibration box is checked as is the GPS connection.
When outside I get a blue led on the GPS board and can take off an fly.

However when I took the X8 to the flying field I couldnt see any reaction to the PH being enabled and when I flew the X8 away and tried RTH nothing happened.
My AL and AH were working well.

I will be doing something daft but at this point all the indicators are telling me the GPS board is calibrated and set up correctly and responding on the setup software to the switch inputs but out in the field there appears to be no GPS functions when flying.

Not a silly question at all. If the ship wants to go somewhere else while the PH or RTH is ON and good GPS signal, its usually due to bad trim settings for the auto-leveling (AL). When the GPS functions are activated the Auto-Leveling feature is activated as well. If the AL is not trimmed properly the GPS will fight it. Lets say for example the AL trim on your ship is slightly off to the right. As soon as AL is activated it will bank right and begin moving. When PH is on it tells the ship to stay put but the AL will say bank right. The GPS will see this and try to correct but if the trim is too far off, the trim will win the battle and you'll have a runaway ship. Follow this procedure: On calm wind day (zero wind) bring the ship to a hover. Activate AL. Observe its trim. Is it trying to move in a certain direction when you activate AL? Keep AL ON and adjust the trim until the ship is stationary. Leave AL ON and land the ship. Disarm. Unplug the HFP battery. Turn off AL on your Tx. Plug in the battery to the HFP. Rearm and bring it to a hover. Activate AL. It should stay in one place. If you trim even with a light breeze it will always think there is a light breeze, drift when there is no wind and fight the GPS. Do not adjust the trim on your RC tx after its set. Also make sure the AL gain is turned up high enough just below the oscillation point. Keep the questions coming. I've had the same questions and many more till I got it nailed.

 

[Stacky]

Not a silly question at all. If the ship wants to go somewhere else while the PH or RTH is ON and good GPS signal, its usually due to bad trim settings for the auto-leveling (AL). When the GPS functions are activated the Auto-Leveling feature is activated as well. If the AL is not trimmed properly the GPS will fight it. Lets say for example the AL trim on your ship is slightly off to the right. As soon as AL is activated it will bank right and begin moving. When PH is on it tells the ship to stay put but the AL will say bank right. The GPS will see this and try to correct but if the trim is too far off, the trim will win the battle and you'll have a runaway ship. Follow this procedure: On calm wind day (zero wind) bring the ship to a hover. Activate AL. Observe its trim. Is it trying to move in a certain direction when you activate AL? Keep AL ON and adjust the trim until the ship is stationary. Leave AL ON and land the ship. Disarm. Unplug the HFP battery. Turn off AL on your Tx. Plug in the battery to the HFP. Rearm and bring it to a hover. Activate AL. It should stay in one place. If you trim even with a light breeze it will always think there is a light breeze, drift when there is no wind and fight the GPS. Do not adjust the trim on your RC tx after its set. Also make sure the AL gain is turned up high enough just below the oscillation point. Keep the questions coming. I've had the same questions and many more till I got it nailed.

Thanks, that makes perfect sense. I was trying to give it a go in windy conditions and had trimmed the AL in that so it wasnt perfect. I will go through it again as soon as the wind dies. Cheers

 

[JZSlenker]

Glad you finally got to play with a GPS board Stacky. The key to good performance is actually the magnetic compass. Do what you can to minimize EMI. Get rid of ferrous fasteners, move power lines away and twist the conductors. When you calibrate the compass make sure your ship is fully equipped with whatever you fly with (camera, batteries, gimbal, video TX). Also make sure all your gear is turned on when you calibrate. (Camera, video TX etc.) Many people miss this step.

 

[Av8Chuck]

Ok lots of great discussion about the GPS module, I focus on the important things. Loved your demo real BUT for your demo reel to be a GREAT demo reel you needed to shoot naked coeds at Upper Bear Hole and tubing on the river.

 

[Stacky]

Glad you finally got to play with a GPS board Stacky. The key to good performance is actually the magnetic compass. Do what you can to minimize EMI. Get rid of ferrous fasteners, move power lines away and twist the conductors. When you calibrate the compass make sure your ship is fully equipped with whatever you fly with (camera, batteries, gimbal, video TX). Also make sure all your gear is turned on when you calibrate. (Camera, video TX etc.) Many people miss this step.

Thanks JZ, I had missed that last step so will revisit it again as soon as the wind drops a bit.

 

[Stacky]

I have the AL perfectly tuned. Dead calm day here so got it done. i have run out of time to test the GPS again so will have to wait till the weekend.
Kind of trying to work out what use the GPS would be to me on a calm day, my X8 once the AL was tuned just sat in one spot without moving, no GPS board in place. I didnt even have to mess with the throttle to keep the altitude right. Didnt need the AH on, it just sat there for half a battery. However it does bore me senseless watching something hover in one spot.

Wish we could fly in dead calm days all the time.

 

[JZSlenker]

Honestly I don't understand the GPS obsession. We only use it for failsafe.

 

[Bartman]

fwiw, i still have some GPS mounting kits in stock. i may need to buy more vibration isolators but the rest of the parts for the kits are on my shelf. the kits work by raising the GPS board (where the magnetometers are located) up off the heli enough to allow the GPS to function properly. it's also helpful to clean up your wiring as some have suggested.

if anyone wants one they can be ordered at the site. for international shipping please email me and we'll handle it manually. the shop isn't going to be developed further so fixing the niggly international shipping bug won't get done before it's taken offline.

bart

 

[mspencer1]

Ok lots of great discussion about the GPS module, I focus on the important things. Loved your demo real BUT for your demo reel to be a GREAT demo reel you needed to shoot naked coeds at Upper Bear Hole and tubing on the river.

Thats what I told my cameraman but NOOO he just wanted to film some boring runners and bicyclists.