SV not seeing the GPS

[bruceh]

I have the 10" Skyview display and have the SV-GPS-250 hooked as shown in the installation instructions. I have verified continuity on all of the 4 signal lines to the GPS. The power line shows +8V (should it be 12V?). I have set up the Serial port #5 as specified in the installation instructions, but I am not getting any GPS data. RX and TX show 0, and I am seeing General Errors counting up. At this point I'm assuming the GPS is bad, but before I remove it and send it back to Dynon, is there anything else I should be checking with my installation? The rest of the Serial ports are working just fine (VP-X, ADS-B, XPNDR) and show valid counts on RX/TX.

Has anyone else had a bad SV-GPS-250?

 

[TRCsmith]

I may be jumping the gun here, but did you check it outside? :

 

[paul330]

Three thoughts:

- Have you configured Port 5 as per the Installation Manual p8.4?

- Make sure you have connected tx to rx and rx to tx NOT tx-tx and rx-rx.  Did that with my radio and had me head scratching for hours.  :

- Make sure you have the correct wires - some of the colours look very similar.

Being indoors won't stop the data transfer - you'd just fail to get a GPS lock.

 

[bruceh]

I pulled the plane out of the hangar today as a final test, and it wasn't able to get anything out of the GPS being outside either. The serial port #5 wires are all correctly connected RX to TX and vice versa. I've only got the single Dynon SV Display. The four wires are all color coded and are hooked up to the 37 pin connector on the SV display as specified in the installation instructions.

 

[bruceh]

Some more trouble shooting today. I tried using the RX/TX lines from Serial port #3 (last screenshot), and same story. Here are some screen shots.

I guess I will call Dynon this week and see about getting it fixed.

 

[dlloyd]

Bruce,
Reread Paul330's post again, item 2. The original manual was confusing for me on the wiring--finally figured out if one device is transmitting, the other receives. If you have 'em backwards, it won't hurt anything, it just won't work.

 

[Dynon]

So if the RX counter isn't showing a continuous counting up, then the display isn't seeing the GPS electrically. I'd start by checking the harness all the way from the DSUB pins to the expected color. The easy one to check is whether there's any voltage across the black and orange wires (power/ground)

 

[bruceh]

OK, problem is SOLVED!

I'm the problem. I had the power/ground wires swapped going to the GPS! I had previously checked the voltage and ground continuity, but for some reason after staring at the wires for several hours I didn't see the problem at the connector on the GPS antenna. Orange shouldn't go to black and vice versa! :

Anyway, I swapped the pins on the connector and the Skyview started seeing the GPS data! I also verified that the ELT is now getting valid GPS data.

 

[Pilotkms]

Im having a similar problem and have checked my wires.  Both my Dynon gps250 and my SL40 are recognized by both Dynon screens but i am not getting any TX counters for either, just RX counts.  The other 3 serial ports have both TX and RX counts. 
I have updated to 13.0.   Plane still in the hangar.  Ideas??

 

[dynonsupport]

This is not an issue. We don't send any data to the GPS-250, so there is no TX activity. We only send data to the SL-40 when you request to tune it, so this will only change when you press TUNE COM.

 

[Pilotkms]

EXCELLENT!
Thanx for the quick reply. Spent 8-10 hours trying to solve this one. Glad its not a problem. Electrical now done so i can put the top on.