thingspeak_room_temp_loop.py

#!/usr/bin/python
import httplib, urllib
import os
import glob
import time


def read_B18_Raw():
    os.system('modprobe w1-gpio')
    os.system('modprobe w1-therm')
    Params = urllib.urlencode({'field1': temp_f, 'key':'my key'})
    Headers = {"Content-type": "application/x-www-form-urlencoded","Accept": "text/plain"}
    conn = httplib.HTTPConnection("api.thingspeak.com:80")

    base_dir = '/sys/bus/w1/devices/'
    device_folder = glob.glob(base_dir + '28*')[0]
    device_file = device_folder + '/w1_slave'
    f = open(device_file, 'r')
    lines = f.readlines()
    f.close()
    return lines

def read_B18():
    lines = read_B18_Raw()
    while lines[0].strip()[-3:] != 'YES':
            time.sleep(0.2)
            lines = read_B18_Raw()
    equals_pos = lines[1].find('t=')
    if equals_pos != -1:
        temp_string = lines[1][equals_pos+2:]
        temp_c = float(temp_string) / 1000.0
        temp_f = temp_c * 9.0 / 5.0 + 32.0
        return "%.1f" % (temp_f)

    try:
        conn.request("POST", "/update", params, headers)
        response = conn.getresponse()
        print temp_f
        data = response.read()
        temp_f = read_temp()
        conn.close()
    except:
        print "connection failed"

#sleep for 16 seconds (api limit of 15 secs)
if __name__ == "__main__":
    temp_f = 0
    while True:
        read_B18()
        time.sleep(16)