Is There an Explanation for Current Readings on HDX whilst its Powered by Backup Battery Only?

[Bardample]

I have just replaced a faulty Dynon EGT probe ( (515 hours since new) on cylinder #1 . I had removed the Earthx ETX 680 battery , as this was faulty as well ( not holding charge after flight, or on the bench after charge out of RV).

When I powered the Dynon HDX with the Dynon backup battery alone, to check that my newly installed EGT probe functioned ( it did) ,I noticed the Ammeter reading was 8Amps and the 'measured output ' from my Monkworkz input was 2.6 Amp. Obvoiusly, the only power supply in the plane at the time was the Dynon supplied back up battery.

Can anyone explain this to me? See the screen shot of part of my monitor at time.

 

[BlueCrab]

From my perspective, explaining this without a schematic, is impossible. I would need to understand how your system is measuring those inputs and any conversions/scaling the Dynon HDX is providing.

 

[F18Sailor]

Bardample,

Can you share your settings config file for the Monkworkz current, presuming you are using the output from the Monkworkz PCB directly? This is what I have, and my readings are not correct (0A shows as 18A on the display):

sensor={
id=MONKWORKZ CURRENT
function=AMPS
pins=C37_P8 C37_P22 C37_P23 C37_P31
name=MZ30_A
min_val=0
max_val=30
resolution=1
round=.1
is_piecewise=0
low_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=6
c_x0=18
}
low_resistance=NONE
low2high_cross=0
high_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=0
c_x0=0
}
high_resistance=NONE
high2low_cross=0
shift=5
}

 

[Rhino]

Are you using the hall effect output from the Monkworkz or a shunt?
Where did you get those polynomial numbers?
If using the proportional current output on pin 5 of the Molex connector, it outputs between 0 to 2.7 volts, corresponding to 0 to 30 amps, so those polynomials seem a bit strange.

 

[F18Sailor]

I'm using the proportional current output on pin 5 of the Molex connector, and you're correct, those polynomials made little sense. I've since updated them as shown below, but haven't had a chance to test them yet. The other questions I have are:
1) How do you select a low_resistance value? I noticed the other ammeter sensors have a 200 Ohm pullup, so I added that, but I also noted those are likely shunt sensors, not proportional.
2) My contact sensor for the Monkworkz alternator doesn't appear to be working correctly. Configuration below, but it would be helpful if someone with a known-working sensor definition would post their copy!

sensor={
id=MONKWORKZ CURRENT
function=AMPS
pins=C37_P8 C37_P22 C37_P23 C37_P31
name=MZ30_A
min_val=0
max_val=30
resolution=1
round=.1
is_piecewise=0
low_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=11.111
c_x0=0
}
low_resistance=PULL_UP_200
low2high_cross=0
high_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=0
c_x0=0
}
high_resistance=NONE
high2low_cross=0
shift=5
}

sensor={
id=MONKWORKZ STATUS
function=CONTACT
pins=C37_P4 C37_P6 C37_P7 C37_P8 C37_P9 C37_P10 C37_P11 C37_P12 C37_P20 C37_P21 C37_P22 C37_P23 C37_P31
name=MZ30_S
min_val=0
max_val=5
resolution=1
round=.1
is_piecewise=0
low_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=1
c_x0=0
}
low_resistance=PULL_UP_10K
low2high_cross=0
high_coeff={
c_x4=0
c_x3=0
c_x2=0
c_x1=0
c_x0=0
}
high_resistance=NONE
high2low_cross=0
}