GPS175/SL30 with Dynon HDX and Garmin G5

In 2021 I completed an upgrade of my Van's RV-9A C-GCPT to allow for IFR flight. I added an IFR Navigator (Garmin GPS 175) and a VHF NAV radio (MGL N16 with Razor). I also added a Garmin G5 display to my Dynon Skyview HDX. Since posting about my new configuration on vansairforce.com, I have been contacted numerous times by builders considering a similar setup. This web page should serve as a detailed explanation of the wiring and configuration that I use to make these components function together during IFR flight. The background photo is from Western Ontario taken during a VFR-over-the-top flight using this configuration. It has proven to be a very usable IFR platform as I work to obtain my IFR rating in 2021.

The Equipment

The Wiring

Navigation Sources GPS 175 - J1751 ARINC 429 IN 1A27 ARINC 429 IN 1B28 RS-232 OUT 19 RS-232 GND 152 ARINC 429 OUT 1A5 ARINC 429 OUT 1B6 RS-232 OUT 28 RS-232 GND 251 MGL RAZOR RS232 TX Port 14 RS232 RX Port 13 ARINC-429 Modules SV-ARINC-429 - D25 ARINC TX A24 ARINC TX B12 Serial RX32 ARINC 1 RX A23 ARINC 1 RX B11 GAD29 - J292 ARINC RX 1A23 ARINC RX 1B11 SV-XPNDR-261 GPS Serial Input3 Displays SV-HDX1100 - D37 Serial Port 3 RX7 Serial Port 3 TX8 G5 - J51 RS-232 RX 14 RS-232 TX 15

The Configuration

SerialARINC
GPS175
Port 1 goes to the HDX, port 2 goes to the transponder to provide ADS-B position. RX Port 1 is air data from the Dynon ARINC module, RX port 2 in not used. TX is sent to both the Dynon and Garmin ARINC modules. Garmin G5 configuration is used.
HDX
Serial 3 format is set to Garmin/Apollo SL30, the Razor control head is set to emulate the SL30. Only setting required is Input Speed=Low. This is to match the G5 requirement.
G5
This is serial data coming from the Razor (emulating SL30). Input 1 is set to Garmin GPS (SDI 2). The other inputs are not used.

Please note that the ARINC-429 configuration is the one specified for the G5 in the installation manual, based on the G5/GAD 29 to GNX 375/SL 30 Interconnect Drawing. These settings do work for the HDX, however the HDX preferred settings do not work for the G5.

I hope that you find this information helpful as you try to configure your airplane.
Please contact me at cjpitre@gmail.com should you need more information. I'd also apprecate an email if you find this helpful, include a picture of your panel.
Claude Pitre Dec 4, 2021.