Attopilot 180A Voltage and Current Sensor

This article explains how to use the AttoPilot for measuring high current and voltages.

Overview

In general it is best to power your Pixhawk, APM 2.5, 2.6, or PX4 with the 3DR power modulebecause it provides solid 5V power and also allows you to read current and voltage. But for cases where you need to measure over 18V (i.e. over 4S batteries) or current over 90A, you should use the AttoPilot 180A current and voltage module which can be purchased from Sparkfun.

Connection to Pixhawk

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Pixhawk/ toAttopilot 180A Voltage/Current Sensor Wiring Diagram

Connecting the autopilot sensor to the Pixhawk requires modifying a DF13 6 position cable as shown in the photo above including connecting:

  • V pin (voltage) to the Pixhawk’s 3rd pin from the left
  • I pin (current) to the Pixhawk’s 4th pin from the left
  • GND pin (ground) to the 1st pin on the left

Connection to APM

../_images/ConnectionDiagram2.jpg

Connect the autopilot sensor to APM as shown in the photo above including connecting:

  • V pin (voltage) to APM’s A1’s S pin
  • I pin (current) to APM’s A2’s S pin
  • GND pin (ground) to APM’s A1 “-” pin

Setup in Mission Planner

To configure the sensor go to the Mission Planner’s INITIAL SETUP > Optional Hardware > Battery Monitor page and set the “Monitor”, “Sensor” and “APM” fields as shown in the image below. If a battery is then connected you should see the “Battery voltage (Calced)” field become populated with the voltage of the battery.

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Note: Due to the voltage scaling of the sensor to 3.3V, the maximum current you can measure with the 180Amp sensor described here is actually 272Amps and for the smaller AttoPilot 90A sensor it is 136Amps.

Calibrating the voltage sensor

You can calibrate the voltage sensor to match the voltage from a hand-held volt meter by following the instructions on the power module calibration page here.