bg_temp-to-screen

#!/usr/bin/env python3
# -*- coding:utf-8 -*-

import os
import sys
import time
import atexit
import argparse
import subprocess
from  mydaemon import Daemon

import Adafruit_DHT
import Adafruit_SSD1306
import Adafruit_GPIO.SPI as SPI

from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont

DAEMON_NAME = 'DMSPi Temp Output Process (id: #ID#)'
DAEMON_STOP_TIMEOUT = 10
PIDFILE = '/run/DSMPi_TOP_#ID#.pid'
RUNFILE = '/run/DSMPi_TOP_#ID#.run'
# Debug mode.
DEBUG = 0

RST = None
DC = 23
SPI_PORT = 0
SPI_DEVICE = 0
disp = Adafruit_SSD1306.SSD1306_128_32(rst=RST)

disp.begin()
disp.clear()
disp.display()

width = disp.width
height = disp.height
image = Image.new('1', (width, height))
draw = ImageDraw.Draw(image)

draw.rectangle((0,0,width,height), outline=0, fill=0)

padding = -2
top = padding
bottom = height-padding
x = 0
font = ImageFont.truetype('/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf', 36)

def kickit():
    humidity, temperature = Adafruit_DHT.read_retry(22, 17)
    if temperature is not None:
        utemp = temperature * 9/5.0 + 32
        ftemp=('{0:0.1f}\N{DEGREE SIGN}F'.format(utemp))
        disp.clear()
        draw.text((x, top), str(ftemp),  font=font, fill=255)
    else:
        print('Failed to get reading. Try again!')
    pass

def get_args():
    '''
    >>> get_args()
    ('start', 5)
    >>> get_args()
    ('stop', 4)
    '''

    try:
        parser =  argparse.ArgumentParser()
        parser.add_argument('action', help='action',
                            choices=['start', 'stop', 'restart'])
        parser.add_argument('uniqid', help='Unique ID')
        args = parser.parse_args()

        result = (args.action, args.uniqid)
    except Exception as err:
        if DEBUG:
            raise
        else:
            sys.stderr.write('%s\n' % (err))

        result = (None, None)

    return result

class MyProc(Daemon):
    def run(self):
        while True:
            draw.rectangle((0,0,width,height), outline=0, fill=0)
            kickit()
            disp.image(image)
            disp.display()
            time.sleep(3)

        atexit.register(self.delrun)

        # Run while there is no stop request.
        n = 0
        while os.path.exists(RUNFILE):
            print('.')
            n += 1

            if (n > 60):
                break

            time.sleep(1)


if __name__ == '__main__':
    try:
        # Get arguments.
        (action, uniqid) = get_args()

        # Create daemon object.
        DAEMON_NAME = DAEMON_NAME.replace('#ID#', uniqid)
        PIDFILE = PIDFILE.replace('#ID#', uniqid)
        RUNFILE = RUNFILE.replace('#ID#', uniqid)
        d = MyProc(name=DAEMON_NAME, pidfile=PIDFILE, runfile=RUNFILE,
                     stoptimeout=DAEMON_STOP_TIMEOUT, debug=DEBUG)

        # Action requested.
        if action == 'start':
            d.start()
        elif action == 'stop':
            d.stop()
        elif action == 'restart':
            d.restart()
        else:
            raise NameError('Unknown action')

        sys.exit(0)
    except Exception as err:
        if DEBUG:
            raise
        else:
            sys.stderr.write('%s\n' % err)

        sys.exit(1)