I have 3 power modules, one from 3DR and 2 clones, they all look like this
The problem is that the amps read 0 until actual amps reach about 2A.
I’ve tuned BATT_AMP_PERVOLT so that 16A reads exactly as 16A, but then when I go back to below 2A, it reads as 0.
I’ve tweaked BATT_AMP_OFFSET to -0.02 so that my idle of 0.5A reads as 0.5A instead of 0, but once I start the motor, it stays at 0.5A until I reach about 2A. Clearly this is a pixfalcon issue where it ignores any voltage on the I/Amps line of the power board until said voltage reaches 0.1V. After that there is an issue that power modules are not linear
Is there any fix to get the pixfalcon to return some amp value below 3A?
A was measured with an amp meter off the battery
V was measured on the power module between Gnd and I
V A A/V
0.037 0.48 13.0
0.040 0.96 24.0
0.059 1.50 25.4
0.068 1.75 25.7
0.086 2.15 25.0
0.105 2.60 24.8
0.120 3.00 25.0
0.200 4.50 22.5
0.370 8.00 21.6
0.530 11.0 20.8
0.670 14.0 20.9
0.800 16.6 20.8
Then, the non linear issue should be fixed in ardupilot I think, I opened a different issue for this: Could AP allow for non linear current sensors?