Skyview Serial Ports

jpharrell · #1 08-11-2013, 11:33 PM

I am planning my panel electrical wiring and I am not clear on the wiring of serial devices to the Skyview system. I have dual skyview displays and have apparently run out of serial ports. I have the following allocated:

Port 1 Rx and Tx - Transponder SV-XPNDR-261
Port 2 Rx and Tx - SV-ADSB-470
Port 3 Rx and Tx - VP-X
Port 4 Rx and Tx - Garmin SL-40
Port 5 Rx and Tx - SV-GPS-250

Both displays are wired to these devices in parallel.

Unfortunately I also have a Trutrak Gemini PFD on order and it needs GPS input also. Is there a way to connect the Gemini to this system without adding another GPS? Can I use another standalone SV-GPS-250 with serial ports wired directly to the Gemini? Or should I be looking at something like an Aera or the new iFly 520 as an independent GPS source?

dynonsupport · #2 08-12-2013, 01:07 AM

I can only assume you wanted the Gemini as a backup. Thus, wiring it to the SkyView wouldn't be what you wanted to do anyway since now you would be tied completely to SkyView.

I'd ask TruTrak what inexpensive, easy to connect GPS they can use. If they can only use a full navigator like a iFly or a Area, you could consider a Dynon D6 or a D1, which cost about the same as a Gemini but don't need an external GPS.

Brantel · #3 08-12-2013, 07:15 AM

All the Gemini needs is a ground track source (actually it can get by without it but it will run in free gyro mode). Any cheap puck style GPS would work fine if it has a regular NMEA output over RS232.

jpharrell · #4 08-12-2013, 09:46 AM

Brantel,

Can you be more specific? I was considering buying a second dedicated SV-GPS-250 for the Gemini but Lucas at Trutrak says a Dynon GPS puck won't work directly since it transmits at 38400 baud whereas the Gemini only supports 4800 and 9600. What puck GPS supports those baud rates?

I was also wondering if there is a compatible bluetooth to serial adapter that I could connect to the Gemini and use a Dual or Bad Elf GPS.

Flyguytki · #5 08-12-2013, 09:58 AM

IIRC the VP-X does not have to be wired to both screens, only one. That would free up one if your data ports. Also in my plane I only wired the transponder to the left side, not to both, again opens up a free port.

Brantel · #6 08-12-2013, 10:03 AM

Byonics sells several GPS pucks but keep in mind most of them work on 5v not 12v....

http://www.byonics.com/tinytrak/gps.php

Garmin has the GPS 18 or the older harder to find GPS 35.

There are tons of these el-cheapo units out there, just make sure they are RS232, watch out for the power requirement, and ensure that they output NMEA at 4800 or 9600 baud.

I would not try the BT thing. That just smells like trouble.

jpharrell · #7 08-12-2013, 10:53 AM

The Byonics puck sounds like it might be a good solution; less than $100 with a 12V adapter. I can hardwire the converter in behind the panel and it provides a completely independent WAAS GPS source so it is more fault tolerant than wiring it to the Skyview. If nothing better comes to light I could be happy with that. Thanks for the help.

dynonsupport · #8 08-12-2013, 11:19 AM

Quote:

Originally Posted by Flyguytki

IIRC the VP-X does not have to be wired to both screens, only one. That would free up one if your data ports. Also in my plane I only wired the transponder to the left side, not to both, again opens up a free port.

FlyGuy, you cannot hook something to only one screen in SkyView. For reasons of redundancy. You will find in your situation that sometimes your VP-X does not work at all, and sometimes your Transponder doesn't. The system assumes everything is wired to every screen, and to the same serial ports on each screen. The advantage of this is you don't lose any features if a SkyView screen fails, unlike some other EFIS systems where the failure of a single screen can lead to most external devices also failing because they are wired to only one place.

It should also be noted that our SV-GPS-250 is NOT a 12V device and cannot be connected directly to aircraft power in case anyone is ever trying to do that.

TrutrakTech · #9 08-12-2013, 02:55 PM

Quote:

Originally Posted by Brantel

Byonics sells several GPS pucks but keep in mind most of them work on 5v not 12v....

http://www.byonics.com/tinytrak/gps.php

Garmin has the GPS 18 or the older harder to find GPS 35.

There are tons of these el-cheapo units out there, just make sure they are RS232, watch out for the power requirement, and ensure that they output NMEA at 4800 or 9600 baud.

I would not try the BT thing. That just smells like trouble.

The GPS-18 works, it's just a pain that the OEM version with accessible wires for the Tx line does not have a built in voltage converter for 12V power usage, it works only on 5 volts. The GPS-16 outputs the right info and is 12V powered, but it's big, bulky, and looks like a model Radome. Our GPS module may be available as early as the end of the year. We are testing one in one of our planes right now.