Why is an HS34 needed to enable GPS steering?
- Thread starter aglock
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Because the only devices that put out roll steering (the Garmin 430/530 and the 480) only put it out on ARINC. It's simply not on the serial line for us to listen to.
gbabcock
New Member
What about for the Garmin GX60, which does output GPSS over serial?
I want to replace my S-TEC 50, which supports GPSS from the GX60.
Regards,
Glenn
I want to replace my S-TEC 50, which supports GPSS from the GX60.
Regards,
Glenn
PhantomPholly
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Serial does not output vertical or horizontal steering commands, only provides horizontal course deviation information.
If Dynon is like all the others it will still follow a course using serial input, but it may "hunt" (zigzag a bit left and right of course). This would still let you fly a nonprecision approach, but never a precision or precision with vertical guidance approach.
If Dynon is like all the others it will still follow a course using serial input, but it may "hunt" (zigzag a bit left and right of course). This would still let you fly a nonprecision approach, but never a precision or precision with vertical guidance approach.
gbabcock
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gbabcock
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Parsing non-NMEA and non-SL30 data out of serial streams hasn't been trivial for us to implement for various reasons. So currently, our products only support GPSS from ARINC sources (through the HS34). There aren't any plans to change this.
gbabcock
New Member
You can't parse this?!?! Well, so much for my future plans with Dynon.
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It is of course technically possible for us to parse it, but it is not simple for us to add this because of the architecture of our system. Given the low demand for this (you're the first that has asked), it is not something we are likely to spend our development time on.
As always, if we have misjudged the demand and there are a lot of GX-60 users out there that want to use our AP and GPSS over serial, please let us know.
As always, if we have misjudged the demand and there are a lot of GX-60 users out there that want to use our AP and GPSS over serial, please let us know.
gbabcock
New Member
Dynon Support,
As a hardware/software developer with over 20 years experience, I find it hard to believe that this is so difficult. Your documentation states that the GX60 is "known to work" over the serial bus (D10A Installation Manual, page 3-5). If you're already reading some data off the serial bus, why can't you read these few additional bytes? You must already be parsing this data just so you can ignore it.
Now my upgrade path is "simply" this:
- Replace my perfectly functional GX60 (enroute and approach certified, fully integrated with the avionics stack including MX20 moving map, etc.) with at least a Garmin 430: $8000
- Buy two servos, an HS34, and an AP74: $2600
This gives me the same capabilities I have today plus vertical rate and preset. No vertical NAV, coupled approaches, vertical GPS, etc. (yes, I wanted the AP76!). All for the bargain price of $10,600 plus installation.
Then next year you want me to throw out the AP74 (and maybe the HS34) and buy NextGen, which will require another major redesign of the panel. At that point I'll finally have an autopilot that has the same capabilities that analog autopilots have had for years.
Dynon, you started out being the avionics company for the kit plane community. Your products were advertised as low cost and flexible to integrate and upgrade, which is why I selected them. I was one of your first customers with the D10, upgraded to the D10A, added the Remote Compass and Heated Pitot, looked forward to the Autopilot.
Yet I was growing concerned that you lost your initial focus. I've been watching your product announcements and reading the forum hoping you would stay the course, but that simply hasn't happened. The heated pitot took three years. The AP76 was announced then dropped. No upgrade to full IFR autopilot unless we go NextGen. Now you won't support my modern GPS.
Instrument panels are not PC's; we don't replace them every two years. I'm sure that there are at least one or two other people in the world with both your EFIS and the popular Apollo GX series GPS. You never stated that there was limited capability or that you would discontinue support for this GPS, but now we're left out in the cold.
I don't know what market you are targeting now, but I guess I'm not in it anymore.
Tell you what: since you don't seem to care much for us D10A owners who don't want to replace our panels, how about going Open Source on the firmware so we can continue to develop it ourselves?
Regards,
Glenn
As a hardware/software developer with over 20 years experience, I find it hard to believe that this is so difficult. Your documentation states that the GX60 is "known to work" over the serial bus (D10A Installation Manual, page 3-5). If you're already reading some data off the serial bus, why can't you read these few additional bytes? You must already be parsing this data just so you can ignore it.
Now my upgrade path is "simply" this:
- Replace my perfectly functional GX60 (enroute and approach certified, fully integrated with the avionics stack including MX20 moving map, etc.) with at least a Garmin 430: $8000
- Buy two servos, an HS34, and an AP74: $2600
This gives me the same capabilities I have today plus vertical rate and preset. No vertical NAV, coupled approaches, vertical GPS, etc. (yes, I wanted the AP76!). All for the bargain price of $10,600 plus installation.
Then next year you want me to throw out the AP74 (and maybe the HS34) and buy NextGen, which will require another major redesign of the panel. At that point I'll finally have an autopilot that has the same capabilities that analog autopilots have had for years.
Dynon, you started out being the avionics company for the kit plane community. Your products were advertised as low cost and flexible to integrate and upgrade, which is why I selected them. I was one of your first customers with the D10, upgraded to the D10A, added the Remote Compass and Heated Pitot, looked forward to the Autopilot.
Yet I was growing concerned that you lost your initial focus. I've been watching your product announcements and reading the forum hoping you would stay the course, but that simply hasn't happened. The heated pitot took three years. The AP76 was announced then dropped. No upgrade to full IFR autopilot unless we go NextGen. Now you won't support my modern GPS.
Instrument panels are not PC's; we don't replace them every two years. I'm sure that there are at least one or two other people in the world with both your EFIS and the popular Apollo GX series GPS. You never stated that there was limited capability or that you would discontinue support for this GPS, but now we're left out in the cold.
I don't know what market you are targeting now, but I guess I'm not in it anymore.
Tell you what: since you don't seem to care much for us D10A owners who don't want to replace our panels, how about going Open Source on the firmware so we can continue to develop it ourselves?
Regards,
Glenn
DBRV10
Active Member
Look on the bright side, they are still around and supportin gsales and service! 
And you get some more digital and analogue I/O points on the DSAB..... its not all bad!
And you get some more digital and analogue I/O points on the DSAB..... its not all bad!
Dynon,
This has been asked of you before...On this very forum and others.
But, the GX series is doomed since Garmin has already obsoleted it and now does not support any repairs of screen related issues since they no longer have a source for the parts to fix them.
Unfortunately the screen seems to be the #1 item that needs repaired on these GX units.
This has been asked of you before...On this very forum and others.
But, the GX series is doomed since Garmin has already obsoleted it and now does not support any repairs of screen related issues since they no longer have a source for the parts to fix them.
Unfortunately the screen seems to be the #1 item that needs repaired on these GX units.
gbabcock,
Just to be sure you know, you can use the GX series over serial and it will work just fine, you just won't get GPSS tracking.....
The AP will fly the normal GPS Nav data from this GPS. Not as good as true GPSS but better than nothing.
It is my understanding that the GPSS update rate out of the GX series is kinda slow anyway so my guess is that the performance of the GX GPSS and any analog AP is far inferior to any digital AP and true GPSS over ARINC 429.
Just to be sure you know, you can use the GX series over serial and it will work just fine, you just won't get GPSS tracking.....
The AP will fly the normal GPS Nav data from this GPS. Not as good as true GPSS but better than nothing.
It is my understanding that the GPSS update rate out of the GX series is kinda slow anyway so my guess is that the performance of the GX GPSS and any analog AP is far inferior to any digital AP and true GPSS over ARINC 429.
gbabcock
New Member
Brantel,
Understood, I stated that in my earlier post.
Actually, I find GPSS with the GX60/S-TEC to be amazing. It tracks with great precision, and can easily handle any oblique angle you throw at it. The data rate has never been an issue, and I'm flying a 200kt aircraft. Tracking the CDI enroute on GPS or NAV isn't even close, and I never use that anymore except for localizers.
The GX60 is ALREADY sending roll commands directly to the D10A in the serial data stream, and the D10A is reading & parsing this stream for other words/data. So this is not a hardware or protocol issue, it's just software. Dynon could translate the GX format to their format if they wanted to, just like other autopilot makers do (TruTrack, S-TEC, etc.).
ARINC 429 isn't anything magic, it's just a "standards-based" interface, which Dynon converts into their proprietary format via the HS34. The GX60 has "true" GPSS in that it outputs horizontal bank angle (roll) and related commands. The fact that it uses a proprietary format doesn't take away from that.
Anyway, it's all academic now. Dynon wants our money for NextGen, so they're not going to give this away.
Regards,
Glenn
gbabcock
New Member
I did a forum search on "GX GPSS" and got many hits. I'm certainly NOT the first to ask. For example, here's a thread on the subject: http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1227289256/0#0
Glenn
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I'm not sure how to respond here, except to say that our design goals and resource allocations always revolve around capturing the vast majority of customers' needs, and there are things that we decide not to implement because the benefit isn't high enough for the enough of our customers. As with any product line, there will be a few special cases that we do not serve optimally.
To get into it a little bit, the GX60 does have a proprietary RS-232 data format, and has elements in its data stream that make it look like both an a NAV radio despite being a GPS only. Our parser wants to explicitly choose between these two sorts of streams when in auto-detect mode, and while modifications are possible to allow for the GX-60, through a dedicated selection or auto-detection that specifically looks for it, they're not trivial given the existing architecture.
Also know that at least half of the effort in making making any changes to the way our product receive serial data isn't in the code itself, but in the regression testing that happens both in beta and in the field once we release firmware that changes the parser. It's not impossible to make changes to support, say, the GX60, and end up breaking some other special case (some of the more popular GPSs, for example, output some odd data that needs to be accounted for) that affects many more people. Historically, we've found these changes very resource intensive.
Anyway, this doesn't change the fact that we don't support GPSS from a GX60 today (as the GX60 doesn't have ARINC-429 output), and we are sorry that we can't easily add it at the moment. As with all feature requests, we will add this for future consideration.
To get into it a little bit, the GX60 does have a proprietary RS-232 data format, and has elements in its data stream that make it look like both an a NAV radio despite being a GPS only. Our parser wants to explicitly choose between these two sorts of streams when in auto-detect mode, and while modifications are possible to allow for the GX-60, through a dedicated selection or auto-detection that specifically looks for it, they're not trivial given the existing architecture.
Also know that at least half of the effort in making making any changes to the way our product receive serial data isn't in the code itself, but in the regression testing that happens both in beta and in the field once we release firmware that changes the parser. It's not impossible to make changes to support, say, the GX60, and end up breaking some other special case (some of the more popular GPSs, for example, output some odd data that needs to be accounted for) that affects many more people. Historically, we've found these changes very resource intensive.
Anyway, this doesn't change the fact that we don't support GPSS from a GX60 today (as the GX60 doesn't have ARINC-429 output), and we are sorry that we can't easily add it at the moment. As with all feature requests, we will add this for future consideration.