IAPD battery lab

battery.py

#!/usr/bin/env python
""" Usage
Run once
$ sed "s/postskript/$USER/g" battery.py
$ sed "s/postskript/$USER/g" "$HOME/.config/awesome/battery_magic.py"
Apped the lua code to rc.lua and then
$ sed "s/postskript/$USER/g" "$HOME/.config/awesome/rc.lua"
$ echo 600 > $HOME/.config/awesome/display_brightness_delay
$ echo 10 > $HOME/.config/awesome/.true

So, reload awesome (modkey + Control + R) and run battery_magic.py.
Near the teacher run:
$ ./battery.py 10   # for 10 sec. delay
"""

import time, os, sys

SUPPLY = "/sys/class/power_supply/"
BRIGHTNESS_DELAY_PATH = "/home/postskript/.config/awesome/display_brightness_delay"

old_brightness = open(BRIGHTNESS_DELAY_PATH).read()[:-1]

def set_brightness_delay(brightness):
    os.system("echo {} > {}".format(brightness, BRIGHTNESS_DELAY_PATH) )

if len(sys.argv) < 2:
    print("Delay expected")
    sys.exit(1)

try:
    set_brightness_delay(sys.argv[1])
    while True:
        time.sleep(1)
        os.system("clear")
        
        ac_on = open(SUPPLY + "AC0/online").read()
        if ac_on.startswith("0"):
            print("Battery", end=', ')
        else:
            print("AC", end=', ')
            
        print("{}%, ".format(open(SUPPLY + "BAT0/capacity").read()[:-1]), end='')
            
        present_rate = int(open(SUPPLY + "BAT0/power_now").read()) / 1000.0
        remaining_energy = int(open(SUPPLY + "BAT0/energy_now").read()) / 1000.0
        last_capacity = int(open(SUPPLY + "BAT0/energy_full").read()) / 1000.0
            
        if present_rate < 0.1:
            print("will never fully charge")
            continue
            
        if ac_on.startswith("0"):
            seconds = remaining_energy / present_rate * 3600
        else:
            seconds = (last_capacity - remaining_energy) / present_rate * 3600
                
        hours = seconds // 3600
        minutes = (seconds % 3600) // 60 
        seconds = seconds % 60
        print("%02d:%02d:%02d" % (hours, minutes, seconds))

except KeyboardInterrupt:
    set_brightness_delay(old_brightness)

hidder_magic.py

#!/usr/bin/env python

import os
import sys
from evdev import InputDevice
from select import select
from subprocess import check_output

CONF_PATH = "/home/postskript/.config/awesome/display_brightness_delay"
TRUE_PATH = "/home/postskript/.config/awesome/.true"

def update_timer():
    if open("/sys/class/power_supply/AC0/online").read().startswith("0"):
        seconds = open(CONF_PATH).read()[:-1]
        os.system("echo {} > {}".format(seconds, TRUE_PATH))

if __name__ == "__main__":

    if os.getuid():
        print("You must be root")
        sys.exit(1)

    update_timer()
    
    devices = map(InputDevice, ("/dev/input/event0", "/dev/input/event16"))  # or what you have
    devices = {dev.fd: dev for dev in devices}

    while True:
        r, w, x = select(devices, [], [])
        for fd in r:
            for event in devices[fd].read():
                update_timer()

rc.lua

--- Append this code to your rc.lua
--- {{{ BATTERY HACK

was_ac = false

power_timer = timer({timeout = 1})
power_timer:connect_signal("timeout", function()

                              local pow_sec = tonumber(awful.util.pread("cat /home/postskript/.config/awesome/.true"))
                              local pow_full_sec = tonumber(awful.util.pread("cat /home/postskript/.config/awesome/display_brightness_delay"))

                              if pow_sec == pow_full_sec and was_ac == false then
                                    awful.util.spawn_with_shell('ruby -e "l=`light`.to_i*2;`light -S #{l}`"' , false)
                              end

                              if string.sub(awful.util.pread("cat /sys/class/power_supply/AC0/online"),1,1) == "1" then
                                 awful.util.spawn_with_shell("echo " .. pow_full_sec .. " > /home/postskript/.config/awesome/.true")
                                 was_ac = true
                                 return
                              end
                              was_ac = false
                              if pow_sec == 0 then
                                 awful.util.spawn_with_shell('ruby -e "l=`light`.to_i/2;`light -S #{l}`"' , false)
                              end

                              pow_sec = pow_sec - 1

                              if pow_sec < 0 then
                                 pow_sec = -1
                              end
                              awful.util.spawn_with_shell("echo " .. pow_sec .. " > /home/postskript/.config/awesome/.true")
end)

power_timer:start()

--- }}}