from machine import Pin, I2C
from utime import sleep_ms, ticks_us
from pico_i2c_lcd import I2cLcd

i2c = I2C(id=1,scl=Pin(27),sda=Pin(26),freq=100000)
lcd = I2cLcd(i2c, 0x27, 2,16)

class DHT22():
  def __init__(self,gpio):
    self.pin=gpio
    self.pin=Pin(2,mode=Pin.OUT)
    self.pin.high()
    self.ckecksum=0
    self.temperatura=0
    self.humedad=0
    sleep_ms(1)

  def getReading(self):
    DHT=self.pin
    DHT.low()
    sleep_ms(1)
    DHT.init(mode=Pin.IN)
    for i in range(2):
      while DHT.value()==1:
        pass
      while DHT.value()==0:
        pass
    data=0
    t1=ticks_us()
    for i in range(32):
      while DHT.value()==1:
        pass
      while DHT.value()==0:
        pass
      t2=ticks_us()
      data=data<<1
      data=data|((t2-t1)>100)
      t1=t2
    checksum=0
    for i in range(8):
      while DHT.value()==1:
        pass
      while DHT.value()==0:
        pass
      t2=ticks_us()
      checksum=checksum<<1
      checksum=checksum|((t2-t1)>100)
      t1=t2
    byte1=(data>>24&0xFF)
    byte2=(data>>16&0xFF)
    byte3=(data>>8&0xFF)
    byte4=(data & 0xFF)
    self.checksum=(checksum==(byte1+byte2+byte3+byte4)&0xFF)
    self.humedad=((byte1<<8)|byte2)/10.0
    neg=byte3 & 0x80
    self.temperatura=(byte3<<8 | byte4)/10.0
    if neg>0:
      self.temperatura=-self.temperatura

while 1:
  sleep_ms(100)
  dht=DHT22(2)
  dht.getReading()
  sleep_ms(100)
  #lcd.clear()

  lcd.move_to(0,0)
  lcd.putstr("Temp")
  lcd.move_to(7,0)
  lcd.putstr(str(dht.temperatura)+ "C")
  lcd.move_to(0,1)
  lcd.putstr("Hume:")
  lcd.putstr(str(dht.humedad)+"%")
  
  #print("Checksum",dht.checksum)
  #print("Humedad= ",dht.humedad)
  #print("Temperatura= ",dht.temperatura)
  #sleep_ms(2000)