MFD AP satellite lock... not

[MarkLloyd]

Hi Guys,

I'm currently setting up the MFD AP in my soon to be completed Z3.  Things have been going ok up to now but I've got no GPS lock.  I'm sure I've had it lock in the past but the OSD is currently displaying Zeros for the Longitude and Latitude and  no display of any sats locked.  I've had it sat in the garden a while, with no luck.   The vtx is at least 12 inches away from the gps

The GPS unit itself shows just a solid blue led when powered up then will blink an additional red led after a short while.  I'm not sure if this means it has actually locked onto sats ? If it does, the osd still reads zero.

Any help would be much appreciated.

Its one of the black versions running 1.16

I have a gps from a FY41 and also an FY31  ...  anyone know if it would be ok to test with these ?

Many thanks

Mark   

[Coyote]

With the GPS indicating like you say would suggest the GPS is getting it's supply and it is locking into satellites. So that's good :)

I would then think it's one of two things :

1) The tx and Rx wires on the GPS cable are reversed at one of the ends so it's not sending the data to the MFD AP

With this case you can swap the two wires to confirm this. No harm will come to the unit if that was or is not the fault.

2) You have the sensor plugged into the wrong socket. In this case the sensor is getting it's power still, but it's output is going to the wrong part of the AP. Easily done with the err sketchy diagrams that can be misleading.

[MarkLloyd]

Thanks Ian,   I'll have a look at that now.

[MarkLloyd]

Well, I've swapped the rx and tx wires but got no leds on the gps so I'm assuming they're the right way round.

I've also tried a spare 4 pin cable with the same result, so it's not a broken wire.  I  assume the gps isn't outputting the signals or the Ap has a problem receiving them on that connector .

I'm connected to the far right vertical socket on the MFD with the ground in the bottom pin.

Would the GPS from a fy41 be ok to connect to test the gps unit ? ( first checking  the 4 wires are in the same positions) ?

I think the gps socket is the same socket for firmware updates, I suppose if it's knackered on this socket it won't allow me to access the firmware on the Ap.




   

[iPeel]

I saw a YT video of some German guy complaining his AP GPS didn't work but the one off his FY did, so I guess they are compatible.

I wonder if MFD have sent you the wrong GPS? Have you tried going into the AP setup screen and changing the GPS type to AAT?

Also if it's been a couple of weeks since you last tried to use the GPS it will need a clean reception for 20 seconds before each satellite is useable even though it's receiving from it. It may be worth turning your camera and vtx off for a few minutes with the bird in the garden then plugging everything back in to see what it claims.

[MarkLloyd]

Many thanks,

I've just pulled the fy41 gps from the funjet ( had to swap the rx and tx wires) .... shoved the plane in the garden and got 8 satellites with  gps coordinates on the osd within about 30 seconds. 

I'll have a look see if I can see any obvious probs with the other gps module and if not I'll contact MFD for a replacement.


Thanks again to both of you for your help    :D

[Coyote]

Which sensor is this is it the new one they are sending out or the Ublox ?

[MarkLloyd]

The one that came with the black MFD  say "R Cirocomm  580"    on the top and "BeStar BS-280 GPS"  on the back.  I can't see any other identification.

As a seperate issue, I turned the tx off inside the house before I went out to pick the plane up from the garden which I shouldn't really have done as it would have put the plane into rth although that  is currently set with a zero throttle on the rx .  As I walked back the few feet to the house the motor fired up at medium throttle. I had no prop on so it wasn't a problem but a suprise.   I had thought with my alt being around 0 and speed almost the same it wouldn't have started.

[Coyote]

Hmm the B eStar is the new one, your not the first to mention this.

Regarding it powering up. It ignores your failsafe throttle when in RTH so it will power the motor up until it hits cruise speed regardless of your failsafe settings. So be cautious of this When in the house remove the props. When you select save model it can for no reason go into RTH and launch at you. I know this because it did it to me, and now I have half the use of one of my fingers lol

[MarkLloyd]

Hi all,

Well I emailed admin at MFD last night to explain the problem with the gps and to ask if they had any suggestions.  Having read the full 300 page RCgroups MFD thread over Christmas I'd seen their feedback to customers was excellent.

Today I had a nice email from Charles which went as follows .....



Hi

Let's check if the GPS is defective.


First please select OSD menu:
SENSORS SETTINGS -> GPS BAUDRATE -> 9600


Maybe the GPS uses 9600bps accidentally. So it can not communicate with the AP.


If you see there is a "0" on the upper-right corner of the OSD, that means the GPS connects to AP successfully.


No matter you do above steps successfully or not, we can use the AP to set the GPS to 38400:

Connect the GPS to AP

Then select:


MISC SETTINGS->UTILITIES->AP GPS->(Execute)


Wait for about one minutes, the AP will write commands to the GPS. Once it's done, select 38400 or DEFAULT  in (SENSORS SETTINGS -> GPS BAUDRATE)


Then let's check if you can see "0" on the upper-right corner of the OSD.


Add me to you whatsapp if possible (+8618688404917)

thanks




Anyway, the GPS has come back to life and I got a quick 8 satellites on the OSD.  :D


I thought I'd been through the whole of the menu options but didn't realise from

MISC SETTINGS->UTILITIES->AP GPS     

there is then a furthur right stick to execute the AP GPS setting.  I just left it at AP GPS and went back

The extra right flick of the stick makes it stop and write to the gps.


Anyway, I'm really pleased, I wondered if I'd accidentally frazzled something even though I'd been careful.
I'm still not sure what made it lose it's original setting.  Maybe I accidentally changed an option whilst scrolling down the menu which
seems easily done.

Hope this helps anyone else who may encounter the problem.

I'll paste this up to the RCGroups thread too.

Regards

Mark

[Coyote]

I was not aware of the write to GPS feature either, nice one for the heads up :)