开源项目:

X750是一款树莓派用的多功能高端UPS电源扩展板。它提供高达8A的大电流输出，提供脚本通过I2C来读取电池容量等信息。

由于官方只给了Python代码，转成Nodejs方便使用。

树莓派上 开启I2C

pi@raspberrypi ~ $  sudo raspi-config

选择 5 Interfacing Options

选择 I2C - Enable/Disable automatic loading.

选择 "Yes" 

const struct = require('python-struct');
const i2c = require('i2c-bus');

const address = 0x36;

const readVoltage = rawData=>{
  console.log('rawData', rawData);
	let packData = struct.pack(">H", rawData);
	console.log('packData', packData);
	let unpackData = struct.unpack("{
	let packData = struct.pack(">H", rawData);
	console.log('packData', packData);
	let unpackData = struct.unpack(" i2c1.readWord(address, 0x2).
  then(rawData => console.log(readVoltage(rawData))).
  then(_ => i2c1.close())
).catch(console.log);

i2c.openPromisified(1).
then(i2c1 => i2c1.readWord(address, 0x4).
  then(rawData => console.log(readCapacity(rawData))).
  then(_ => i2c1.close())
).catch(console.log);

支持硬件及软件关机 https://github.com/geekworm-com/x750

sudo apt-get install python-smbus 
sudo apt-get install i2c-tools 
git clone https://github.com/geekworm-com/x750.git
cd x750
chmod +x x750.sh
sudo bash x750.sh
printf "%s\n" "alias x750off='sudo x750shutdown.sh'" >> ~/.bashrc
sudo reboot

// 测试软件关机
./x750off