Mike:
Got my laptop mavlink radio working after driver fix.
There is nothing wrong with your voltage data. It is the control board (MPNG/MP). The Mavlink radio to MP is reporting the same thing as your data as far as the Voltage. When high current draw the voltage is different from my watt meter but your data matched the mavlink reported data shown on MP transmitted by radio link.
So I think this is a bug in MPNG/MP. Not your program. Your program just take the data and convert it to FrSky hub format (at least that is what i am using).
This evening I ran the current as high as 36A (shy of full throttle because the quad started became unstable because of the back wash and it is right at my feet
![Wink ;)](./images/smilies/icon_e_wink.gif)
)and your current reporting is spot on (after yesterday's calibration). But with higher current the voltage is up to 2.1V higher than A2 or watt meter but it matches perfectly with the mavlink radio reporting.
This voltage difference starts around 2.6~2.8
A then getting bigger and bigger when current draw is higher and higher.
I will start setting up a new 450 quad with another FC board (the HK AIOP V2 ~ Crius AIOP v1. I know all my stuff is kind old from 1 1/2 to 2 yrs ago
![Razz :P](./images/smilies/icon_razz.gif)
). I will use the last MPNG to check if they corrected the issue when it is ready.
The current board I am using is the HK red AIOP board as RCHH's illustration pic for connection of power module wire. In there I have a MPNG older version from 1 1/2 to 2 yrs ago, not the latest or last version of MPNG for 8bit processor. (But I know everything in there is calibrated so I did not update)
May be the real APM FC will report actual voltage correctly.
Just like RCHH reported the battery symbol and % are right on.