circuitpython/esp8266/modules/dht.py

33 lines
794 B
Python

# DHT11/DHT22 driver for MicroPython on ESP8266
# MIT license; Copyright (c) 2016 Damien P. George
import esp
class DHTBase:
def __init__(self, pin):
self.pin = pin
self.buf = bytearray(5)
def measure(self):
buf = self.buf
esp.dht_readinto(self.pin, buf)
if (buf[0] + buf[1] + buf[2] + buf[3]) & 0xff != buf[4]:
raise Exception("checksum error")
class DHT11(DHTBase):
def humidity(self):
return self.buf[0]
def temperature(self):
return self.buf[2]
class DHT22(DHTBase):
def humidity(self):
return (self.buf[0] << 8 | self.buf[1]) * 0.1
def temperature(self):
t = ((self.buf[2] & 0x7f) << 8 | self.buf[3]) * 0.1
if self.buf[2] & 0x80:
t = -t
return t