vbpiper

vbpiper

Well Known Member
OK, I'm goin' nuts (on many levels, but that's a different post :>). I can't get my Dynon D10A to see my 296. I have been on Dynon's forum (thanks, Brantel) and have checked continuity from the GPS plug to the pin 3 in the DB9 connector. Both units are grounded at the firewall on the same "forest of tabs". I just updated the Dynon through the DB9 and ran the "Detect Firmware Version" successfully, so the wiring from the DB9 to the unit should be OK. I have satellite lock on 3 to 4 satellites. The GPS is set to output NMEA/VHF at 9600 baud and it is set to "Normal" in the advanced screen, and in the Dynon HSI serial setup screen it is configured for NMEA 9600 baud. I have also tried it with the Dynon set to AUTO on both the format and speed. I can't think of anything else to check.
Is there a way to determine if the GPS is actually outputing a signal?
Do I need to have the GPS powered up before the Dynon?
I know the functionality I gain is minimal since I don't yet have the autopilot, but my AR side needs to solve this.
ANY suggestions are gratefully accepted!
Thanks.
 
Location, location, location...

Ward, it has to be the location! See, I'm in Arlington (just north of Tacoma for those of you trying to make the connection), and I'm having the same problem with my Lowrance. Maybe it's just the GPS Gods of the Pacific NorthWest!

I took the data signal from my Lowrance to a terminal board, and then use that terminal board to supply signal to my Trio EZ Pilot autopilot and my Dynon and my transponder. I know that I'm getting a good signal from my Lowrance GPS, since my A/P always points me in the right general direction. But "no joy" on the Dynon. I haven't started down the path of troubleshooting yet, so I'll be interested to hear any hints or techniques to get this figured out.
 
Yes you can check the output of the gps by making up a connector to connect it to the serial port of a computer and then run any terminal emulation software to watch the data on the serial port.

No you do not have to turn the GPS on first.
 
Only 3 to 4 satellites? Four is the absolute minimum to receive lat/lon and gps-derived altitude. This is a complete WAG but I would not be surprised if the GPS is not outputting NMEA until you get a better lock. I would run a GPS antenna outside to get a better lock and try it again.

BTW: What is AR?
 
Good thought Jamie,

Ward, does the 296 show a 3D position lock? If not, I am with Jamie, the Dynon won't respond unless it is getting all the data it requires. It will just say "waiting on GPS fix" or something like that if it knows there is a GPS connected but it is not sending all the data.
 
Satellite lock

The GPS was showing 3D positioning, but maybe I need to move the plane to a different spot to acquire more satellites.
Right now, the Dynon doesn't even show the GPS on the list in the HSI setup page (setup > HSI > GPS).
Brantel, I'm not familiar with terminal emulation software, so that's way over my head!
I'm thinking I'll just wait until I can move the plane to a better location to see if more satellites will help. Plenty of other stuff to do.
Thanks for all of the input!
 
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vbpiper said:
Right now, the Dynon doesn't even show the GPS on the list in the HSI setup page (setup > HSI > GPS).
Click to expand...

This may be your clue - if it doesn't show up on the list, then it sounds like the Dynon has not yet been properly configured. Only configured devices show up on the list.

Cheers,

Bill
 
Configuring Dynon

Bill,
Thanks for the input. I have gone into the Dynon HSI setup and configured it for NMEA input at 9600 baud (and I have also tried it set to "auto"). If there are any other screens in the Dynon that require configuration for the unit to see the GPS, I can't find them. Stumped doesn't begin to describe my mindset.
I will try the remote antenna to see if more satellites will help.
Thanks, again.
 
Ward,

It is tough to visualize your menu's as I am not in front of my panel. I will be at the airport tommorrow evening and will take a look and see if there is anything you might be missing.

I am confused when you say it is not in the list. I don't remember a list but I need to punch the buttons myself to be sure.

What version of firmware you running?
 
Firmware

The firmware is the latest (5.2?) just downloaded from Dynon's website. It loaded just fine into the Dynon through the same DB9 female connector to which I am connecting the male DB9 from the GPS. (Unplugged the GPS and plugged in the USB-to-serial cable from the laptop for the update).
The menu I'm referring to is under setup > HSI > scroll down to GPS. On the right side of the screen is a window that looks like it should show all GPSs connected to the unit, but none appear. At the bottom right of the screen it shows something like GPS.....0. ( I'm not sure of the exact text that appears as I am not at the airport at the moment).
I'm concerned that I am missing something very basic. As an old friend who was a copier repair tech once told me, the first question they ask during a tech support phone call is "Is it plugged in?"
 
Ward,

Either due to the fact that I have an HS34 or there might be a difference in the menu structure between a D100 and a D10A, I do not have the menu that you are refering to.

Can you take some pics of what you are seeing and post them? I am sure we can help you with this, I just don't recognize what you are discribing....
 
Ward,
I am using a D10A with a 396 GPS.
I have the garmin set to output NMEA IN/ NMEA OUT and the HSI/GPS overlay works fine. Check your 296 manual on page 116-119 for GPS output set up and check you have the VIOLET wire and not the Blue wire connected to the D10A. Hope this helps.
Good Luck,
 
The 296 has two serial ports and you can use either one. Port one is the blue wire, port two is the violet wire.

Just make sure that you have the correct port setup on the GPS as what you are using.

I read somewhere that even though the 296 has two ports, only one can output NMEA data at any given time so you cannot have both ports set to output NMEA data.

The 396 and 496 use the other port for the weather so you only have one available on those.



rich said:
Ward,
I am using a D10A with a 396 GPS.
I have the garmin set to output NMEA IN/ NMEA OUT and the HSI/GPS overlay works fine. Check your 296 manual on page 116-119 for GPS output set up and check you have the VIOLET wire and not the Blue wire connected to the D10A. Hope this helps.
Good Luck,
Click to expand...
 
Ports

Right now I have the blue wire hooked up, but I may as well try the violet one. Can't hurt? I do have the GPS configured to output to port 1, which the Garmin cable has labeled as the blue wire.
Brantel,
I will take a couple of pictures tonight.
Thanks everyone for the help.
 
You also need to change the 296 serial output sentence. The factory default does not work:


Garmin 296: NMEA or NMEA & VHF Out. Advanced:Normal NMEA:9600 NMEA:9600 Yes

(emphasis mine)

Vern
 
Another possibility; some GPS units have a configuration screen where you tell the unit what NMEA sentences to include in its serial output stream. I know my Avmap is configurable but not sure about the Garmin. The Dynon EFIS requires these specific sentences, $GPRMC, $GPRMB, $GPGGA and one of $GPBOD or $GPAPB. Without these sentences the Dynon will not be able to fully use the GPS information.
 
Does not matter as long as you have the port settings correct. That drawing only shows one possibility.

I have a 296 connected with the BLUE wire and it works just fine. The BLUE wire is for port one.

You can use the VIOLET wire if you want, does not matter. Just ensure the settings are correct for that port.

If he has a bad port one, that is a different story....

rich said:
Check out the 296 pilots guide page 134 (142 of 168)pdf.
The VIOLET wire goes to Autopilot/ NEMA Device.
The BLUE wire goes to GSD 20 /Sounder.

http://www8.garmin.com/manuals/GPSMAP296_PilotsGuide.pdf
Click to expand...
 
The 296 does not have finite control over the sentences but as long as he sets it to output NMEA data and the advanced NMEA setting is set to NORMAL, it will provide the correct sentences.

647jc said:
Another possibility; some GPS units have a configuration screen where you tell the unit what NMEA sentences to include in its serial output stream. I know my Avmap is configurable but not sure about the Garmin. The Dynon EFIS requires these specific sentences, $GPRMC, $GPRMB, $GPGGA and one of $GPBOD or $GPAPB. Without these sentences the Dynon will not be able to fully use the GPS information.
Click to expand...
 
The "Normal" setting fixed my issues...

as well (after loading vers 5.2). I just came back from Augusta after shooting an ILS and it worked beautifully. Then when near home and my VNAV notice came on the 496, the glideslope also appeared on the D-100 HSI page....cool....defaulted to 500 FPM sink.

It disappeared when I reached my 'target' height of 1000'.

Can I reset my target altitude to have further glideslope guidance?

TIA,
 
glideslope

Pierre,
I don't think you can. My 396 drops the glide slope 1-2mi from the airport and I tried changing the target altitude . Garmin portables won't let V-NAV down to the RWY. A liability issue I think.
 
Pierre,

There are several settings in the setup menu for controlling the VNAV features of the 496.

There is also a way to create user waypoints and edit their altitude to a fake altitude below ground level in order to get VNAV all the way to the ground. Be carefull if you do this and do not use it for an actual IMC approach as you might go dirt diving....:eek:

Garmin disables the VNAV when using database waypoints to attempt to prevent people from using these handhelds as their sole means of navigation for real approaches.
 
Solved-kind of

I went out to the hangar tonight and disconnected the 296 in order to connect the violet wire (port 2) instead of the blue port 1 wire. Cut the blue one and hooked up the violet wire temporarily to just the Dynon and, like magic, the HSI was a thing of beauty. Then when I installed the connectors to the violet wire, the wire from the Dynon, and the wire to the GTX-327, again no HSI. So I cut the wire to the transponder and the HSI works like a charm. Apparently the connection to the txp was the problem all along. I have no idea why. The harness for the txp came pre-made from the avionics shop and labeled, so either I mis-read the label when I installed it awhile ago, or it was wired incorrectly. My suspicion is that I mis-read or misunderstood the labeling.
I assumed that the 296 would drive both the txp and the Dynon, so I am assuming installer error.
Thank you SO much for everyone's ideas and help. I can't tell you how much this community has enhanced my building experience! I hope I can someday get to the point where I can contribute a small percentage of what I have gained from this forum.
 
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Great to hear you figured out part of the issue. Most likely you were grounding the line to the 327. Fix that and you should be golden. You can drive them both from the same line, just setup the 327 for the baud rate and NMEA. (if your 327 firmware supports NMEA)
 
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Brantel said:
GYou can drive them both from the same line, just setup the 327 for the baud rate and NMEA.
Click to expand...

Does the GTX 327 support NMEA input now? Last time I asked around, it didn't have that feature (although that was a while back).

mcb
 
I think some people here on the board have said that the latest firmware has the ability to use NMEA for the standby switching. ????? (Matt confirms that this feature is not supported)

Then again I do remember someone trying and then moving to use an air switch on the squat switch input....
 
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Brantel said:
I think some people here on the board have said that the latest firmware has the ability to use NMEA for the standby switching. ?????
Click to expand...

I took a look (I have my ways...) and from what I can tell, NMEA input is not supported by any Garmin transponder.

mcb
 
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