Grt Hx and efii wideband oxygen sensor display

Post Reply
Norcalrv7
Posts: 11
Joined: Sun Jan 10, 2016 7:47 am

Grt Hx and efii wideband oxygen sensor display

Post by Norcalrv7 »

I'm installing a grt Hx system in my rv7 that will have electronic engine management by EFII. I'm wondering if there is a way to use the 0-5v output from my wideband oxygen sensor to feed a air fuel ratio display on the Hx. I was thinking possibly through one of the aux analog inputs?


Thanks

Caleb
JimB
Posts: 87
Joined: Tue Mar 12, 2013 12:52 am

Re: Grt Hx and efii wideband oxygen sensor display

Post by JimB »

Caleb,

In theory the Hx analog inputs can display a 0-12 volt signal. The documentation gives instruction on how to use these for trim indicators. Perhaps Jeff will answer how to configure them for your specific purpose. I can't find any documentation on how to configure them in general. Originally they were used for analog signals from a Nav or GPS receiver but those functions are now done by the ARINC interface.

It is fairly easy to configure an aux input on an EIS and then display that on your Hx. EIS will display straight line data, so if your air fuel ratio varies in a linear manner, EIS can take that signal and include it in the RS232 output to your Hx where you can configure the display. If you need help with this way of doing it, let me know. In my Europa I use 5 of the six EIS Aux inputs and only one of those is using a GRT supplied device (Man Press). The other 4 are sensors I supplied and configured - 2 fuel quantity, differential fuel pressure and amps.

Jim Butcher
Europa XS Rotax 914
Norcalrv7
Posts: 11
Joined: Sun Jan 10, 2016 7:47 am

Re: Grt Hx and efii wideband oxygen sensor display

Post by Norcalrv7 »

I was able to set up an AUX analog input and even name it AFR on the HX engine display page. The wide band comes with documentation about what voltage = what AFR, so in theory it should work. Gauge comes next week, Ill post my findings here.

Caleb
Norcalrv7
Posts: 11
Joined: Sun Jan 10, 2016 7:47 am

Re: Grt Hx and efii wideband oxygen sensor display

Post by Norcalrv7 »

Some time later and different things about my project have re-ignited the desire to have AFR displayed directly on the EFIS. I have gotten close, but the numbers aren't spot on. Hoping someone knowledgeable about the GRT systems can help with some setup numbers. Here are my current settings for AUX4

Image

Image

Caleb
Bobturner
Posts: 444
Joined: Mon Mar 11, 2013 6:34 pm

Re: Grt Hx and efii wideband oxygen sensor display

Post by Bobturner »

I am totally unfamiliar with this device. But if it puts out a voltage, I would think you want the internal pull up off.
Norcalrv7
Posts: 11
Joined: Sun Jan 10, 2016 7:47 am

Re: Grt Hx and efii wideband oxygen sensor display

Post by Norcalrv7 »

Update: A slope setting of 50 and an offset of 200 with the pullup resistor setting to off is close within a few tenths of an AFR point.
Post Reply