showpower

#!/bin/bash -u
# Script_name     : showpower
# Author          : Bert Lindeman
# Description     : Show variables related to EV3 battery
# Version         : v1.3
# Date            : 2014-11-04
# Usage           : showpower
# Notes           : The field "status" has a fixed value "Discharging" 
#                   this is by kernel design.
# Copyright       : 2014 Bert Lindeman
# License         : GPL-3.0+
#
#============================================================================
#
# Changelog        
# Date     By       Description
# 20141104 BL       prepare for release v1.3
# 20140914 BL       small cleanup
# 20140826 BL       0 add script header
#                   0 made a bit more robust
#============================================================================

devide_1000000 () {
   volt=$(bc <<< "scale=7; $2/1000000")
   printf "%20s : %11.3f\n" $1  $volt 
}

    #
    cd /sys/devices/platform/legoev3-battery/power_supply/legoev3-battery
    echo "printing info from `pwd`"
    #
    #
    printf "%20s : %11s\n" "Battery  type"  `cat type`
    printf "%20s : %11s\n" "technology"     `cat technology` 
    devide_1000000 "  current_now"                `cat current_now`
    #
    if [ `cat present` == 1 ]; then
      ISpresentBOOL="YES present"
    else  
      ISpresentBOOL="NO absent"
    fi
    printf   "%20s : %11s\n" "present"      "$ISpresentBOOL"
    #
    printf   "%20s : %11s\n" "scope"        `cat scope`
    printf   "%20s : %11s %s\n" "status"    `cat status` "(fake value)"
    devide_1000000 "  voltage_max_design"         `cat voltage_max_design`
    devide_1000000 "  voltage_min_design"         `cat voltage_min_design`
    devide_1000000 "  voltage_now"                `cat voltage_now`
    # just for verification:
    echo -e "  uevent:            \n`cat uevent`" # too many lines of output