Current - arthurbenemann/ardupilot GitHub Wiki

http://ardupilot-mega.googlecode.com/svn/ArduPilotMegaImages/currentsensor.png

If you make these changes to your APM shield you will be able to see your system battery voltage and current on a GCS in real time. Power efficiency in watts/distance can be displayed and if the battery capacity is entered, "est. time remaining" could be available (this depends on the GCS).

Use the !AttoPilot 90A/50V Voltage/Current Sensor, which is available from SparkFun (shown above).

The sensor provides a scaled output for battery voltage and current. The outputs are designed for a 12 bit 3.3V ADC. Full range is 51.8 Volts and 89.4 Amps.

Connect the !AttoPilot sensor to APM as shown in the photo. Use the third and fourth voltage sensor pins and the adjacent ground pin. (Note that if you use a current sensor, you cannot use these pins for voltage measurement. But since a current sensor is so much more accurate in determining remaining battery capacity, you probably won't care.)

Solder on a 3 pin header. The 4th pin from the bottom of the row is ground (the black lead). The next pin up is battery voltage (the red lead). The 3rd pin is the battery current (white lead).

http://ardupilot-mega.googlecode.com/svn/ArduPilotMegaImages/AttoPilot_current.jpg