CHIP Auto Shutdown based upon battery level

chip_batt_autoshutdown.sh

#!/bin/bash

# 2016 ROBERT WOLTERMAN (xtacocorex) (modified by Dushyant Ahuja)
# WITH HELP FROM CHIP-hwtest/battery.sh

# THIS NEEDS TO BE RUN AS ROOT
# PROBABLY SET AS A CRON JOB EVERY 5 OR 10 MINUTES

# SIMPLE SCRIPT TO POWER DOWN THE CHIP BASED UPON BATTERY VOLTAGE

# CHANGE THESE TO CUSTOMIZE THE SCRIPT
MINVOLTAGELEVEL=2500
MINCHARGECURRENT=10

# TALK TO THE POWER MANAGEMENT
i2cset -y -f 0 0x34 0x82 0xC3

# GET POWER OP MODE
POWER_OP_MODE=$(i2cget -y -f 0 0x34 0x01)

# SEE IF BATTERY EXISTS
BAT_EXIST=$(($(($POWER_OP_MODE&0x20))/32))

if [ $BAT_EXIST == 1 ]; then

    BAT_VOLT_MSB=$(i2cget -y -f 0 0x34 0x78)
    BAT_VOLT_LSB=$(i2cget -y -f 0 0x34 0x79)
    BAT_BIN=$(( $(($BAT_VOLT_MSB << 4)) | $(($(($BAT_VOLT_LSB & 0x0F)) )) ))
    BAT_CRITICAL=$(echo "($BAT_BIN*1.1)<=$MINVOLTAGELEVEL"|bc)

    # CHECK BATTERY LEVEL AGAINST MINVOLTAGELEVEL
    if [ "$BAT_CRITICAL" == "1" ] ; then
    
        # GET THE CHARGE CURRENT
        BAT_ICHG_MSB=$(i2cget -y -f 0 0x34 0x7A)
        BAT_ICHG_LSB=$(i2cget -y -f 0 0x34 0x7B)
        BAT_ICHG_BIN=$(( $(($BAT_ICHG_MSB << 4)) | $(($(($BAT_ICHG_LSB & 0x0F)) )) ))
        BAT_ICHG_CRITICAL=$(echo "($BAT_ICHG_BIN*0.5) <= $MINCHARGECURRENT"|bc)
    
        # IF CHARGE CURRENT IS LESS THAN MINCHARGECURRENT, WE NEED TO SHUTDOWN
        if [ "$BAT_ICHG_CRITICAL" = "1" ]; then
            shutdown -h now
        fi
    fi
fi