Not getting GPS fix to my ELT

[Mike_Hillger]

I am having a problem getting confirmation that my AKC E-04 ELT is getting a GPS fix. I have dual Dynon 10" Sky Veiws with the SV GPS-250. I have the ELT connected as per directions. Mini din connector pin 1 is 12v from VPX, pin 2 is test wire connected to my test lead with the resistor and LED, pin 3 is ground, pin 4 is connected to serial port #1 Tx from SV (Brown with orange stripe from both SV's). SV is booted and GPS has a fix. A screen shot of Serial Port #1 is attached.
The ELT is set at the default 9600 baud rate. My LED test wire does blink when connected directly to the serial TX wire and ground.
I called and Mike at ACK told me that he doesnt think Dynon speaks the right language to ACK and they may be working on this for future updates. Should I be able to send a fix to ACK? If so, is my setting correct?

 

[bobl_51]

I have the same setup and it works for me.
If your test LED blinks, that's confirmation its connected correctly according to the ACK manual.
(If you disable serial port 1, does the LED stop blinking?)

 

[Mike_Hillger]

My LED only blinks when it is connected directly to the output TX pin from SV with the ELT unplugged. This is suggested in the troubleshooting section of the ELT manual to check to see if the test LED is funtional. I have gone back to SV installation manual and saw this;

Dynon ADAHRS/EMS/SYSTEM/NMEA Data Outputs
To output real-time data to an external serial device, such as a serial data logger, ELT, or other device that accepts NMEA or Dynon formats:
1. Wire a serial transmit line from one display to the receive line on the external serial device.
2. Ensure there is a shared ground between the D700/D1000 and the external serial device.
3. Configure the serial port on the display appropriately under SETUP MENU > SYSTEM SETUP > SERIAL PORT SETUP, selecting the desired output data format.

Could it be that I have the two serial out wires from the SV's wired together and then to the ELT? The instructions above says "Wire a serial transmit line from one display to the receive line on the external serial device."

 

[Dynon]

Actually, with recent versions of SkyView system software, you do in fact want BOTH displays' serial output connected to any serial receive. We missed updating that particular clause. What it should say is: "If you have multiple SkyView displays, a serial transmit wire from each SkyView display must be connected to the external device in parallel." This normally isn't possible (connecting two transmit wires to one receive), but with with a SkyView system it works because the displays coordinate so that only one display ever transmits at once. This reason we have it designed this way is so that you don't lose any serial device connectivity, even in the event of a failure of a single display.

We'd suggest checking that you're actually using the SkyView serial port that you think you're using (trace the wires back to the pins on the 37-pin connector, and then make sure that's the serial port you think it is.

 

[Mike_Hillger]

Are you saying that the brown wire with the orange stripe is not the Serial port #1 tx wire on the Skyview factory harnesses? Could the factory made a mistake building the harness?.... I have modules hooked up to all the other serial ports and all of them with their respective modules. :-/

 

[dynonsupport]

Anything is possible. The brown wire with the orange stripe is supposed to be serial port 1, but given that it isn't working the way you expect, one reasonable thing to do is check that it isn't mis-wired anywhere.

 

[Mike_Hillger]

For anyone else searching these forums looking for the solution to my problem....I resolved my issue by adding the jumper to the ELT setting the baud rate to 4800. Then I programed the output from Sky View serial port #1 to 4800 and the test led blinked confirming the ELT was getting the GPS position. (9600 did not work, 4800 did).