Triple Red Flash Insanity

[jrlederer]

Hello everyone,

I feel a bit out of place asking questions about the pretty straightforward WKM, especially after having had success with almost every other FC on the market currently, for both single and multirotor helicopters, but here goes:

I purchased a WKM-View about 4 or 5 months ago, but as my schedule would have it with testing other flight controllers and spending much of my time flying working configurations and not wanting to unnecessarily perform a FC swap, I only just got around to opening the package two days ago. I mounted all hardware and everything's connected and responding so no problem there. I even test flew it and it went very well. The only issue I'm having is that I continually get three red flashes, ad absurdum. It's beginning to drive me mad.

From what I understand, three red flashes indicates no 3-D fix from the GPS, but is there a way to tell if anything is getting to the GPS at all? I have checked to ensure the module is getting powered, at least, by plugging other components into the port that's on the wire going from the MC to the GPS module, and whichever I plug into there gets powered properly, so I assume GPS is receiving power.

What should I do? Is this a condition that I will be able to remedy, or does it involve sending in or a replacement?


Kindly,

Jonathan

 

[snurre]

Strange.
Does it respond normally when you perform compass calibration?

There is no video TX running on the ship, is it? (1.2 GHz harmonics can block gps effectively)

 

[jrlederer]

The compass calibration causes proper colored feedback during calibration, yes. Then after that, straight back to triple reds.

 

[snurre]

Any video link active onboard?

Since compass calib works it would indicate that the gps unit is present on the can-bus.
How long time in open terrain did you wait for a fix? First time will take longer due to cold start.

 

[kloner]

also make sure it's out in the open outside

 

[Warlock]

I have only had my F-550 WKM a very short time. I always get the red flashing light as you mentioned if I am in normal mode. It can sometimes take several minutes for the light to go from 3 blinks to 2 and then one, and then none. When there is none, your locked in on the satellites. Swith to atti mode and then the light goes yellow or yellow with the red flashing light if I switch to atti mode right away. But in my case the red light quits blinking after a few minutes. And for some reason, the next time I fly it that day, it takes a short time to have the red light quit blinking. When I switch to gps mode the light goes purple. How long have you waited for he light to quit?

 

[jrlederer]

Thank you all for your replies. it's the damnedest thing, kloner you hit the nail on the head. I finally ventured outside and it behaved like a different animal. The only reason I was really mystified to begin with is that my ArduPilots (both v1 & v2), Autoquad 6, both MKs, and assorted Multiwii's ALL typically get sync even inside; I must live in a very GPS rich portion of Los Angeles. With this WKM, I went at least out on the patio with a relatively clear view of the sky but still no end to the red triplets.

I find it very odd that the reception should be so finicky, would updating to the v2 that they recently produced to rectify the SH problems be of any utility to me? Also, while I have all your (much appreciated) attention, is there not a way to connect to the setup utility via the data radio, to avoid having to physically plug the unit in to the computer in order to adjust settings other than one at a time with X2/X3?

Thanks again!

 

[Tahoe Ed]

At this point the answer is no. Data Link does not support gain adjustment. It could be an enhancement in the future.

 

[DennyR]

Here in Cyprus we have to avoid the urban canyon as it looses GPS quite easily.

 

[jrlederer]

As for V2 GPS/compass module providing substantial improvement of satellite acquisition? I must admit, after having much experience with many (majority) of the available FC, I do recognize pretty comfortable flight characteristics without needing much effort to on figure. The jury is still out as to "best in show". Anyone have any input who's had experience with the YS-X6 system?

 

[OneSkidShort]

Hi Jonathan,

After you turn on your tx and plug in your battery (outside with no obstructions), how long are you waiting? The reason I ask is if it has never acquired satellites before, it could take a very long time. I have heard of folks plugging in and waiting over half an hour till the reds go. After that, it should be fairly quick. Give it a try.

 

[ksrimoungchanh]

I am wondering if copper tape or something like this would help http://www.stewmac.com/shopby/item/...ictures&_suid=1346198526933004224084188919747

I normally get good GPS signal, but I have been having to wait some good 5 mins before I see 1 or 2 red. But then in other times, I get it right off. I do notice that it does remember enough so that after your first flight, it will connect faster.

KS

 

[DLien]

Has anyone looked for or found an alternative to DJI’s GPS/Compass module?

I am usually in the “wait 5 to 10 minute” camp to get to 2 or fewer red flashes. Then there are times I get a lock on the first floor of my 2 story house! I’d like to find a unit that will reliably acquire the GPS signal without the wait. There's a lot of functionality (position-hold, RTH, waypoints, failsafe) that the WKM depends on a reasonably solid GPS signal. It seems odd to me that there are no options for change here. BTW, I have never had an issue doing the dance…

 

[kloner]

you need a more compatible fpv transmitter. all my dji fc's are locked in within 10-20 sec.

 

[DLien]

The Vtx (Immersion's 600 mw on 5.8) doesn't seem to have any impact on the GPS lock speed. I don't even have it on-board at the moment and it still took more than 5 minutes just to get to 2 red's. The only thing consistently transmitting is Spectrum's telemetry module.

If there are no other options, I think I need to look into doing some shielding and see if I can isolate the GPS antenna better. The only other option that has crossed my mind is to power it up daily. There have been times when it has sat idle for a week or 2 at a time. Perhaps more use equals less searching and better performance! Just an idea.

 

[kloner]

5.8 does interfere with gps,,, not as bad as 1.3, but like that....... 433 rc control, 2.4 video and sats work excellent together

Try unplugging the power to the vtx and powering it up to see if it makes a difference.

 

[RC Flying]

Brilliant thread title! I think your location can make a difference, like in some places I get no red flashes really quickly, and in others it takes ages (all with 50 miles radius). There could be other things interferring with the signal, like buildings and other types of transmitters. It does help if you can get you GPS as high as possible, or as far away from the other electronics as possible.
Sometimes, if you get bored waiting, you can hover in the air 20 feet or so and pick up sats quicker.

Also the same amount of satellites aren't in site of your GPS all the time, and they aren't all straight overhead - so some may be coming at you at an angle that is obscurred by buildings of mountains etc. See: http://upload.wikimedia.org/wikipedia/commons/9/9c/ConstellationGPS.gif

I just put up with the fact that sometime it takes ages, when it's better to walk away and not stare at it, and sometimes it works really quickly.

 

[DLien]

Thanks for the ideas. I'll give each of them try as soon as the weather cooperates a bit. It's forecast to have a bit of everything that you could ask for over the next couple of days, except for clear skies.