Voltage Sensor on HK MegaPirate MultiWii AIO board
On my old KK2.0 board there was an integrated voltage meter. On the new KK 2.1.5 board there is even a header for the voltage detection. But on my new HK MegaPirate MultiWii AIO there is no voltage sensor integrated at all. It is very important to know the voltage of the battery pack, so I decided not to buy a voltage sensor, but instead to build my own. I used a simple electric circuit of two resistors, a voltage divider. Very useful for me was this page.
So I used this two resistors R1=110 kohm and R2=47 kohm (You can use resistors with other values, important is the ratio R1/R2). I also find this webpage very useful. After about 10 minutes and some soldering my voltage divider was ready. I connected it to the analog Pin0 on my MegaPirate AIO and enabled the voltage sensor in Mission Planner. Then I needed to calibrate the voltage sensor. I used this very good manual on the ArduCopter official webpage. That’s it. Now I can check the voltage of my battery during flight using the Droid Planner 2 app on my smartphone.