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O2 Sensor output AFR

dmattmul

Well Known Member
Has anyone wired their 5 volt AFR output into their EFIS (Garmin G3X in my case) to log AFR and display on their screens? (Any interference with splitting the signal) I'm using EFII with a PLX O2 sensor. Thanks
 
I got the PLX devices 0-5v box for a wideband on my new turbo swap motor.

I think I can put the 5v in via the GEA24 P244-31 with 32 as its ground.
Then handle the scaling from the Config menu.

Might be changing O2 sensors every 20-30 hours but i've found using the wideband in race-cars running 100LL that you pretty quickly get the hang of what Fuel flow makes the Lambda correct enough.

Climb is still primarily set by CHT within a general range of fuel flow.
And I'm guessing that Cruise Altitude X equals Fuel flow Y (+/- a gallon) 99% of the time.

That's my hypothesis at least.
 
Has anyone wired their 5 volt AFR output into their EFIS (Garmin G3X in my case) to log AFR and display on their screens? (Any interference with splitting the signal) I'm using EFII with a PLX O2 sensor. Thanks

I have no idea if it’s possible to get it on the efis but I do know that if you leave an SD card in the S32 controller you’ll be logging AFR that way.
 
Sure, not an issue sending the signal in. Send it in on one of the GEA's other voltage inputs, just as you noted (I used GP 3 / Pos 3 - J244-12), and set up the voltage scaling on the input. I haven't had any issue with signal splitting after almost 4 years. And just add a new O2 sensor to your annual CI consumables rotation.
 
The PLX has a 0-5v outputs, but no “Sensor Ground” per se
I can wire that 0-5v signal IN to a MISC input on GEA24

But does it need a corresponding ground referenced to or from that PLX box?
Example if I use GEA p244 Misc 5 input on pin 30 does it also need to see a specific Lo on 32?

Or is that just regular airframe ground and I’m overcomplithinking?
Guess I could tie it with the 14v input power’s ground to the PLX but all ground should be same same?
 
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The PLX has a 0-5v outputs, but no “Sensor Ground” per se
I can wire that 0-5v signal IN to a MISC input on GEA24

But does it need a corresponding ground referenced to or from that PLX box?
Example if I use GEA p244 Misc 5 input on pin 30 does it also need to see a specific Lo on 32?

Or is that just regular airframe ground and I’m overcomplithinking?
Guess I could tie it with the 14v input power’s ground to the PLX but all ground should be same same?

That 5V output is referenced to the PLX boxes ground, which should also be the airframe ground. GEA24 also has the airframe ground as a reference. No need for a dedicated ground for this type of signal. Some type of signals are sensitive and best to feed all power and ground from the receiving instrument. This type of signal (stepped, variable voltage) is not one of those.

Larry
 
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Neat!
Will take some noodling to decide on range markings.
 

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