#### zukenj

•   • 202 ##### Voltage sensor
« on: June 09, 2017, 05:27:36 pm »
I followed the instruction in:
https://librepilot.atlassian.net/wiki/display/LPDOC/Configure+a+Current-Voltage+sensor

My Voltage sensor is 30V/90A, how do you calculate the Sensitivity?

In order to use 50V/90A you'll have to do the following:
Convert everything to Volt, so Volt/Volt and Volt/Amp:
63.69mV/V / 1000 = 0.06369 V/V
36.60mV/A / 1000 = 0.0366 V/A

Then calculate the values to insert in Voltage and Current Factors:
VoltageFactor = 1 / 0.06369 = 15.701
CurrentFactor = 1 / 0.0366 = 27.322

Thanks
FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

#### f5soh

•     • 4572 ##### Re: Voltage sensor
« Reply #1 on: June 09, 2017, 05:53:16 pm »
Generally you can assume the output values from sensor are around 3.3V at full scale and calculate directly the factors :
30V / 3.3 = 9.9 for VoltageFactor
90A / 3.3 = 27.27 for CurrentFactor

Voltage calibration is pretty easy without any previous data:
- Apply power
- Check voltage displayed in PFD
- Check real voltage value measured
- Increase / decrease Voltage factor
- Find the right value so both value displayed are the same.

For current measurement you will need to set approximate value and quiet current value adjusting the "CurrentZero", do a flight and check if the energy consumed matches the capacity added after battery charging.
Finally apply a coefficient to the CurrentFactor value according to the board/charger measurement ratio for fine adjustment.

#### zukenj

•   • 202 ##### Re: Voltage sensor
« Reply #2 on: June 09, 2017, 09:03:45 pm »
Thanks putting the new values in place.
FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS