control_osd_and_specialbuttons.py

control_osd_and_specialbuttons.py

#!/usr/bin/python
#
# Skript sollte mittels der folgenden Zeile in der crontab hinterlegt werden:
# @reboot /home/pi/display_overlay/control_osd_and_specialbuttons.py >/tmp/osd.py.log 2>&1
#
# TODO Shift button einlesen und Befehle ausfuehren
#
import RPi.GPIO as GPIO
import array
import os
import signal
import subprocess
import math
import smbus
import serial
import time
from subprocess import *
from config import *



currentIcon = ""
ser = serial.Serial(
   # ttyS0 -> GPIO serial (mini UART)
   # ttyACM0 -> USB serial
   # ttyAMA0 -> Bluetooth serial
   port='/dev/ttyS0',
   baudrate = 57600,
   parity=serial.PARITY_NONE,
   stopbits=serial.STOPBITS_ONE,
   bytesize=serial.EIGHTBITS,
   timeout=2
)



def changeicon(percent):

    global currentIcon
    if currentIcon != percent:
        currentIcon = percent
        cmdLine = PNGVIEWPATH + "/pngview -b 0x000F -l 3000" + percent + " -x 430 -y 1 " + ICONPATH + "/battery_" + percent + ".png &"
        newPngViewProcessPid = int(subprocess.Popen(cmdLine.split(" ")).pid)
        if DEBUGMSG == 1:
            print("cmdLine: " + cmdLine + ", newPngViewProcessPid: " + str(newPngViewProcessPid))

        out = check_output("ps aux | grep [p]ngview | awk '{ print $2 }'", shell=True)
        for pid in out.split('\n'):
            if pid.isdigit() and int(pid) != newPngViewProcessPid:
                if DEBUGMSG == 1:
                    print("killing: " + str(pid))
                os.system("kill " + pid)

        if DEBUGMSG == 1:
            print("Changed battery icon to " + percent + "%")
    else:
        if DEBUGMSG == 1:
            print("Changing of icon not needed")

def endProcess(signalnum = None, handler = None):
    os.system("killall pngview");
    exit(0)

def readBatteryVoltageFromArduino():
    
    # 'V' command is for reading battery voltage. Response example: 4.1234 (V)
    ser.write(bytes('V'))
    batteryVoltage = float(ser.readline())
    print "batteryVoltage: %f V" % batteryVoltage
    
    return batteryVoltage



# Prepare handlers for process exit
signal.signal(signal.SIGTERM, endProcess)
signal.signal(signal.SIGINT, endProcess)



if DEBUGMSG == 1:
    print("Started osd and special button script")

while True:
    ret = readBatteryVoltageFromArduino()

    if ret <= VOLT0:
        changeicon("000")
    elif ret <= VOLT20:
        changeicon("020")
    elif ret <= VOLT40:
        changeicon("040")
    elif ret <= VOLT60:
        changeicon("060")
    elif ret <= VOLT80:
        changeicon("080")
    else:
        changeicon("100")

    # newline
    print("")
    time.sleep(REFRESH_RATE)