What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

GRT EFIS Horz 10.1 Typical Wiring Diagram

gmcjetpilot

Well Known Member
Anyone direct me to wiring diagram. Just looking for examples. Yes the manuals have pinouts, but lacking some details. No need to reinvent the wheel, common practice, tips and tricks.

Questions:

1) Wire diagram examples

2) Using Safe Fly & TRIG TT22. Safe-Fly provides GPS to EFIS and Trig TT22. The EFIS will be the head for TT22. How do you config the ADS-B parameters unique for aircraft.

3) ICOM A220 pins and config. Understand it's similar Apollo (Garmin) SL40. It will not tune the radio, only push Freqs into standby.

4) panel mount USB extension cable for updates

5) Stratux ADS-B Dual Receiver (portable, open source type), Updated software/firmware needed?

6) PMAG Electronic Ignition (Dual) Tach Outputs.

7) Redundant OAT input to EIS and EFIS, AND redundant warning light output EIS and EFIS? Please advise.

My equip list is below:
GRT Horizon 10.1 with AOA and Touch Optional
GRT EIS 4000 SW Ver 44S46F (older EIS)
GRT External Digital Magnetometer
GRT Safe-Fly GPS
Trig TT22 00745-00-01 Transponder (not purchased yet)
ICOM 220A (with serial-in) VHF Transceiver
Stratux ADS-B Dual Band Receiver (Open Source) w/ USB Out
Intercom (stand alone stereo)
Electronic Ignition, Dual P-Mag (with Tach Output)
 
Last edited:
Some responses in line with your questions.

1) Wire diagram examples
** mine are hand-drawn so likely of no use to you (mine is an HX but wiring is the same)

2) Using Safe Fly & TRIG TT22. Safe-Fly provides GPS to EFIS and Trig TT22. The EFIS will be the head for TT22. How do you config the ADS-B parameters unique for aircraft.
** split the RS232 output of the SafeFly so that it provides RS232 position information to both the EFIS and TT22 at the same time, that way if the EFIS or the TT22 dies the other unit will have GPS data.

3) ICOM A220 pins and config. Understand it's similar Apollo (Garmin) SL40. It will not tune the radio, only push Freqs into standby.
** for clarity are we to assume you want to use the EFIS to push frequencies to the ICA220?

4) panel mount USB extension cable for updates
** I have three GRT EFIS devices installed and made simple brackets which mount the USB ports underneath the instrument panel, out of the way. I use very compact USB sticks so they are totally unobtrusive.


5) Stratux ADS-B Dual Receiver (portable, open source type), Updated software/firmware needed?
**always check GRT's website as they push new software without having a means of notifying customers. This makes it more of a "pull" from the customer's perspective. The last update has a fair number of changes related to ADSB data processing thus I suspect it best if you run the latest version. 2.01 released in October 2022.

6) PMAG Electronic Ignition (Dual) Tach Outputs.
** I used the tach output signal from the P-mag directly to the EIS but with a series resistor to provide some short-circuit protection. EMagAir insists the tach output is short-circuit protected so that resistor likely isn't necessary. Boots and suspenders for me as I like to keep the engine running.

7) Redundant OAT input to EIS and EFIS, AND redundant warning light output EIS and EFIS? Please advise.
**I run a single warning light for 3 EFIS and one EIS, plus I use an independent oil pressure switch with its own warning light to provide a redundant indication of loss of oil pressure. I also have configured aural warnings from the HX. I find the on-screen warnings are plenty visible without a need for a warning light from the EFIS.
** Redundant OAT... I have done this and have discovered this is a waste of money and effort. If you lose the EIS and its ability to share OAT with the EFIS, what difference will it make, save for that one combination of a dead EIS AND flight in near-icing conditions? The number of button presses required to make the EFIS swap from EIS to dedicated OAT is something I would not undertake in flight so redundant OAT really doesn't buy me anything. On the other hand, having OAT provided to the EIS makes it really easy to have it provided to another EFIS should one opt to install additional displays. Love the inter-display link for this and other similar features like sharing altimeter setting.
 
As Mark (above) has indicated, software in your unit is similar to the GRT Hx. Several of your questions (e.g., configuring your adsb parameters) can be found in the 3 Hx manuals, plus supplements (especially TT22 supplement) found on the grt web site under ‘Hx and older EFIS units’.
It is important to have a direct connection from gps to TT22, for adsb-out, again as Mark noted. You want to minimize internal time delays.
Warnings: I kept both, but with different limits. e.g., EFIS CHTs flash red at 420F. I understand I need to consider reducing them. EIS big red light flashes red at 430F. I know I need to fix this NOW.
 
Last edited:
For your Stratux, it works best using a serial card in the Raspberry PI. You can get them from the Stratux Store on Amazon. Get it there so the chip is properly configured. With that card, Stratus will connect to GRT serial port at 115200 baud. The Stratux documentation on the GRT website is way out of date.

Jim Butcher
 
THANK YOU GREAT TIPS.

I have plowed through my first draft (I know it is missing a few things). Appreciate looking at for critical critique.

Wiring up the EIS, Magnetometer, Com Radio, got that. That looks like a no brainer (I think).

The Stratux, h&jeuropa thanks for your help. See my post below. I was going to use the existing USB to a serial converter (people recommend Model TU-S9).

The TT22 Trig Transponder has TAMP1 and TAMP2 (both A and B). I went with the TAMP1A and B in my diagram. I am not using the dedicated Trig control head and letting the EFIS do all the controlling. IS AN IDENT BUTTON NEEDED? I assume the GRT EFIS has a IDENT button (touch or hard).

GROUNDS GROUNDS GROUNDS AND MORE GROUNDS.... What is best practice. I assume the grounds between the GRT EFIS Horiz 10.1 and each serial device is needed directly and not through the A/C power ground. The EFIS does not have many GROUND ports so I assume you gang them together. I am concerned about RF interference and ground loops and noise. Do you use any shielded wire or twisted pair or don't worry about it?

I want to use MOST conservative wiring practices to avoid any weird mystery issue that might be hard to solve. Just avoid it with good wiring. However not sure what is GOOD and what is not.

CONFIGURATION CONFIGURATION.... So is there a cheat sheet on this. It seems per comment above (thank you) there is more detail for the older EFIS which have similar configuration menus? I don't want to reinvent the wheel. If there is a tutorial with all the common settings that would be the treat.

THIS IS MY EFIS WIRING BASE LINE
https://imgur.com/a/YNNXxoF
 
Last edited:
For your Stratux, it works best using a serial card in the Raspberry PI. You can get them from the Stratux Store on Amazon. Get it there so the chip is properly configured. With that card, Stratus will connect to GRT serial port at 115200 baud. The Stratux documentation on the GRT website is way out of date.

Jim Butcher
So I already have the USB "serial" port on the Raspberry Pi. Is that what you are referring to?

https://www.amazon.com/Stratux-Seri...72082645&sprefix=stratux+store,aps,107&sr=8-5

I did not build this Stratux so not sure about compatibility of card, but have had a look at it. I am guessing it is not compatible. If this does not require an external adapter that is cool, and would be the way to go.

I was planning on a USB to Serial Adapter recommended by some folks, Model TU-S9, dongle. Not sure 100%, it's all a learning curve and experience. Part of the fun.
 
Last edited:
...

GROUNDS GROUNDS GROUNDS AND MORE GROUNDS.... What is best practice. I assume the grounds between the GRT EFIS Horiz 10.1 and each serial device is needed directly and not through the A/C power ground. The EFIS does not have many GROUND ports so I assume you gang them together. I am concerned about RF interference and ground loops and noise. Do you use any shielded wire or twisted pair or don't worry about it?

...

THIS IS MY EFIS WIRING BASE LINE
https://imgur.com/a/YNNXxoF

I ran all the grounds I could to the panel ground, which is connected via a very short pair of cables to the cabin side firewall ground, which is connected to my engine side ground. It's effectively one ground. I have grounds in these three places for wiring convenience. Everything on the panel is connected to the one ground.

I have headset noise when my alternator is on, but it's very slight. Probably an unhappy diode, not RF, but I can't be sure. Nothing else generates any noise at all - flaps, strobes, trim, transponder - all quiet. Just the alternator.
 
You may wish to dedicate a serial ports IN and OUT to the EIS and the A/P Servos.

EIS - later if you decide to set all the config info from the EFIS and have the EIS “remote” -OR- if you purchase the “66R” remote box, you will need this to send info TO the EIS.

A/P - While the EFIS sends commands TO the servos, the servos need to send info BACK to the EFIS as in “I need some help on the trim buddy!!”.

Keeping these in’s and out’s on the SAME port makes it easy to find and configure and keep track of.
 
Ident. My home airport frequently asks even vfr traffic to ident, so, while you can push the efis button (on the Hx, holding the right hand button down for >1 sec takes me right to the transponder control screen) I found it much more convenient to run a single wire from the TT22 connector to a button on my control stick (ground to activate ident function).
Grounds. I used a copper buss bar on the aft side of the firewall as a single point ground, and used it as much as possible. That said, the RS232 ports are all connected to the efis ground, so you can’t help but have some ground loops. So, for short wire runs, I just used regular insulated 20 gauge wire. The signals are ‘high level’ (many volts) and I have encountered no noise issues. Maybe luck? For arinc signals I twisted the A and B lines together, no external shield. For audio lines I did follow ‘best practices’ guidelines: shielded twisted pairs, with the shield grounded only at the audio panel; dedicated ground wire from phone/mike jack to audio panel (‘float’ (insulate) the jack off the airframe) and twisted with the ground wire, the signal wire, jack to audio panel. I have no noise whatsoever.
 
That is the correct Stratux serial card. It uses one of the PI USB ports. Jim Butcher
I misspoke I do not have USB card out. I do have ONE USB Port but the GPS is blocking it. Too bad the RJ45, HDMI or Mini USB-B can't be used (mini USB used for power). This is my Statux and the USB-Serial dongle I think might do the trick below.

Inside my Stratux ADS-B
https://imgur.com/a/2AtDAiS

USB to Serial TU-S9 Dongle
https://www.trendnet.com/images/products/photos/TU-S9_v2/TU-S9_d01_2-(mirror).png

The Stratux ADS-B over WiFi to iPad works great. Wonder if WiFi receiver to serial adapter can be made to work? Personally I like the idea to hardwire it, but wonder if WiFi adapters can work.
 
Last edited:
Some responses in line with your questions....
Great Info. The Hx Documents is a goldmine of Info.
Yep Bob T., you and Mark's input, Hx Docs. has applicable details to Horz 10.1, great. GRT thought I'm smart enough to figure out Hx Info applied? Fooled them! :)

I ran all the grounds I could to the panel ground
Roger.

You may wish to dedicate a serial ports IN and OUT to the EIS and the A/P Servos.
Good Catch. Done. Not seeing EIS Serial IN? It might be my SW version, have older EIS with Serial OUT, but if it has Serial IN I'll wire it.

Good tips. Ident....efis button...IDENT. single wire from the TT22 connector to a button...Grounds. I used a copper buss bar..... regular insulated 20 gauge wire.... arinc signals I twisted the A and B lines together, no external shield. For audio lines......
Got it. Done.

That is the correct Stratux serial card.
Yep I do not have a USB card as I thought. See post above.
 
Last edited:
Good Catch. Done. Not seeing EIS Serial IN? It might be my SW version, have older EIS with Serial OUT, but if it has Serial IN I'll wire it.

Unless you have a remote mounted EIS the only use I know of for wiring the EIS serial in port is for any (unlikely) software updates. I never bothered wiring mine.
 
It appears you have a Raspberry B which has built in WiFi. With that you have 4 USB ports. Use two for radios, one for GPS and one for serial board. I think the GPS board may give more clearance if it is mounted in the other USB socket.

Or maybe just use the 978 receiver, since everything is transmitted to you on 978, even the 1090 transmissions. That is what I do since my Raspberry PI is an early model without WiFi, so I have a WiFi card in one USB, GPS, 978 and serial in the other three.

Jim Butcher
 
Another thought, after looking at some photos, I remember that I used a USB extension cable on the USB port adjacent to the GPS. The cable end is small enough to clear the GPS. In my case my 978 receiver is connected that way. You could put the serial board on a short cable.

Jim Butcher
 
Below is my REV 2 drawing using some of the great suggestions and catches.
My Wiring Diagram Rev 2
https://imgur.com/a/ozrgiUd

What do you think?

Q) Not sure about Sure-Fly Pin 15 ADS-B Out? Does that go to EFIS or ADS-B Receiver. The Trig TT22 Transponder gets GPS from Pin 19.

Q) "Discrete" pins B2, B3 and B8, what do they do?

Q) Power Input Prime, 2nd, 3rd. It does not give much info. It warns or recommends EFIS be off until after engine start. It does say EIS can be on, which is good and mandatory since you need OIL Pressure right after start. I prefer to have EFIS on for engine start, may be with 2nd battery that is not driving starter for starting and will hold it's voltage. Thoughs. :rolleyes:
 
Below is my REV 2 drawing using some of the great suggestions and catches.
My Wiring Diagram Rev 2
https://imgur.com/a/ozrgiUd

What do you think?

Q) Not sure about Sure-Fly Pin 15 ADS-B Out? Does that go to EFIS or ADS-B Receiver. The Trig TT22 Transponder gets GPS from Pin 19.

Q) "Discrete" pins B2, B3 and B8, what do they do?

Q) Power Input Prime, 2nd, 3rd. It does not give much info. It warns or recommends EFIS be off until after engine start. It does say EIS can be on, which is good and mandatory since you need OIL Pressure right after start. I prefer to have EFIS on for engine start, may be with 2nd battery that is not driving starter for starting and will hold it's voltage. Thoughs. :rolleyes:

I (and I am sure others) use a secondary/auxiliary battery connected to the secondary power input. It keeps the EFIS happy during starts as it is NOT connected to the starter in any way.
 
Another thought, after looking at some photos, I remember that I used a USB extension cable on the USB port adjacent to the GPS. The cable end is small enough to clear the GPS. In my case my 978 receiver is connected that way. You could put the serial board on a short cable. Jim Butcher
Thank you very much. After research and your help and others help, I have a plan. The internal GPS board, with internal and external antenna is too wide. One solution is the VK-162 USB GPS, to free up space and get rid of that double wide GPS board, making space to use the free USB. That free USB takes the TU-S9 the USB to serial dongle, which apparently has been successfully used for this application. The GPS dongle is $15 and Serial dongle is $12. The down side is the 1090 Mhz Antenna jack is in the way of the USB to Serial cable, however I can move the antenna to the other end of the case. It's doable. I was just using it on battery power, WiFi to my Android Tab S2 with "FltPlan Go". it works well. It will work with the GRT EFIS. I think I have to upload firmware image and update firmware.
 
Using the TU-S9 may not work. Early on there was one version of Stratux software that supported those dongles. Then Stratux developed software for the serial card. I think that was about version 1.2. I'm thinking support for the dongle was dropped at that time. Why not get a short USB cable, maybe 1 ft and use the serial card you have? You might need to shave down the edge of the GPS card and/or the edge of the USB cable, but it all should work. Be sure your Stratux has at least version 1.4 software. Current software is 1.6r1.

Looked at your diagram, Stratux is output only (115200 baud) , no need for input from EFIS. Likewise I think EIS is only output to EFIS (9600 baud) , no need for input from EFIS.

Are you aware that Stratux will also present an attitude display on your iPad? It's not a bad backup.

Jim Butcher
 
ADSB delay

I have a similar setup and was seeing a serious delay in the traffic displaying on the efis. There are some software updates to the newest stratus builds that prioritize important traffic (I.e traffic). It is labeled as an European version but works fine and the traffic latency was eliminated.
Jeff at GRT acknowledged the issue and said he also made the change to their adsb receiver but NOT the stratux build on their website.

Link here https://github.com/cyoung/stratux/releases
 
See my notes below. Thank yoiu! Happy New Years All. :D
Using the TU-S9 may not work. Early on there was one version of Stratux software that supported those dongles. Then Stratux developed software for the serial card. I think that was about version 1.2. I'm thinking support for the dongle was dropped at that time. Why not get a short USB cable, maybe 1 ft and use the serial card you have? You might need to shave down the edge of the GPS card and/or the edge of the USB cable, but it all should work. Be sure your Stratux has at least version 1.4 software. Current software is 1.6r1.
Roocking the latest greatest Stratux SW 1.6r1 version, released over 2 years ago. I bought my Stratux after this, about 2 yrs ago. I know how to flash a new image on the SD Card, so I will update if/as required. I am not against the Serial Card you mentioned on Stratux Amazon store, but I read it did not NOT work for some (with older SW version than mine). As far as GPS, the TU-S9 also seems to be a winner. Pick a plan and try it. The Serial and GPS cables are not expensive.

Looked at your diagram, Stratux is output only (115200 baud) , no need for input from EFIS. Likewise I think EIS is only output to EFIS (9600 baud) , no need for input from EFIS.
Yes, agree thank you. I just put it in there for grins and felt like drawing lines, ha ha. I will remove it. EIS4000 also has serial in, which will do nothing with my EIS SW 46/47 version. Which is OK. I plan on panel mounting the EIS so I can see and program it directly.

Are you aware that Stratux will also present an attitude display on your iPad? It's not a bad backup. Jim Butcher
Yes Sir I am aware the basic Stratux App gives basic GPS derived attitude, GPS track, GPS altitude, GPS speed. However it does not have a AHAR or solid state gyro like some of the commercial portable ADS-B receivers have. Never really tried it in flight, as I have the Flight tracking map up on my tablet.

With Flight Plan Go and WiFi, the Stratux on battery pack power, I enjoy the color Navigation, ADS-B traffic, NEXTRAD, METARs, TAFs. I download charts, sectional, airways, approach plates, A/FD, Airport Diagrams, TAF's, NOTAMS, current weather on the ground with WiFi before departure. That's equivalent to 40lbs of paper on a 2lb Tablet. Even without the Stratux, the Tablet has built in GPS and works well stand alone. Stratux issue is TBD but not a big mystery. Worst case I buy the GRT's ADS-B receiver, but 99.9% sure the Stratux will work.
 
Last edited:
I have a similar setup and was seeing a serious delay in the traffic displaying on the efis. There are some software updates to the newest stratus builds that prioritize important traffic (I.e traffic). It is labeled as an European version but works fine and the traffic latency was eliminated.
Jeff at GRT acknowledged the issue and said he also made the change to their adsb receiver but NOT the stratux build on their website.

Link here https://github.com/cyoung/stratux/releases
Thank you, That is good news. I have SW 1.6r1. BTW There are two European versions of 1.6r1, one is for USA (but still says Europe). It has to do with what group has taken the dominate effort and most accepted updates of this OPEN source software; the community deems the Euro 1.6r1 most stable with best features. A little confusing, but there is a redit thread on this subject. I don't want to get into the weeds, just make it work. Fingers crossed the electron gremlins shine on my installation, and no magic smoke is released, as all electronics run on smoke and mirrors. Ha ha. Happy NEW YEARS.... Everyone !!!!
 
Last edited:
Back
Top