This service to support the Adafruit INA219 board. It can be used to measure Voltage, Current and Power. 

Adafruit INA219 product page

Steps to use the INA219

1. Connect the GND, VCC, SCL and SDA pins to the corresponding i2c pins on the Arduino or Raspberry PI. 

2. Connect the GND to GND on the source that you want to measure.

3. Connctect V- and V+ in the circuit that you want to measure. For example you can connect V+ to the battery + and V- to the cable that you normally would have connected to the battery.

4. Start MyrobotLab and test the AdafruitIna219 service using the example script.