#coding:utf-8
import RPi.GPIO as GPIO
import time

def get_dht11():
    channel =4 
    data = []
    j = 0

    GPIO.setmode(GPIO.BCM)

    time.sleep(1)

    GPIO.setup(channel, GPIO.OUT)
    GPIO.output(channel, GPIO.LOW)
    time.sleep(0.02)
    GPIO.output(channel, GPIO.HIGH)
    GPIO.setup(channel, GPIO.IN)

    while GPIO.input(channel) == GPIO.LOW:
        continue
    while GPIO.input(channel) == GPIO.HIGH:
        continue

    while j < 40:
        k = 0
        while GPIO.input(channel) == GPIO.LOW:
            continue
        while GPIO.input(channel) == GPIO.HIGH:
            k += 1
            if k > 100:
                break
        if k < 8:
            data.append(0)
        else:
            data.append(1)

        j += 1

    print("sensor is working.")
    print(data)

    humidity_bit = data[0:8]
    humidity_point_bit = data[8:16]
    temperature_bit = data[16:24]
    temperature_point_bit = data[24:32]
    check_bit = data[32:40]

    humidity = 0
    humidity_point = 0
    temperature = 0
    temperature_point = 0
    check = 0

    for i in range(8):
        humidity += humidity_bit[i] * 2 ** (7-i)
        humidity_point += humidity_point_bit[i] * 2 ** (7-i)
        temperature += temperature_bit[i] * 2 ** (7-i)
        temperature_point += temperature_point_bit[i] * 2 ** (7-i)
        check += check_bit[i] * 2 ** (7-i)

    tmp = humidity + humidity_point + temperature + temperature_point

    if check == tmp:
        print("temperature :", temperature, "*C, humidity :", humidity, "%")
    else:
        print("wrong")
        print("temperature :", temperature, "*C, humidity :", humidity, "% check :", check, ", tmp :", tmp)

    GPIO.cleanup()
    if check == tmp:
        return [temperature,humidity]
    else:
        raise Exception("wrong!")