In my recent review about the Li-po Rider module, I wrote that a little problem was the absence of a chip that could monitor the state of charge (SoC) of the connected battery.
You can find several IC for that function; I chose the MAX17043 by Maxim, for the following interesting features:
- it doesn’t require an external sense resistor
- you can use an i2c interface to talk with it
This IC isn’t friendly for hobbistics: Maxim manufactures it in packages that aren’t easy to be soldered; this is the reason why I brought from DSSCircuits a breakout board, Lipo Fuel Gauge.
That module has two JST connectors (2mm pitch), one for the battery and one to connect in cascade the system to be powered; in addition you can find the PINs for i2c signals (SDA and SCL) and for alert signal (ALRT).
I wrote an Arduino library to use the MAX17043 IC; the connection between Arduino and the Lipo Fuel Gauge module is very simple:
- SDA -> AN4
- SCL -> AN5
- GND -> GND