circuitpython/drivers/dht/dht.py
2022-01-06 14:00:03 +11:00

45 lines
1.0 KiB
Python

# DHT11/DHT22 driver for MicroPython on ESP8266
# MIT license; Copyright (c) 2016 Damien P. George
import sys
if sys.platform.startswith("esp"):
from esp import dht_readinto
elif sys.platform == "mimxrt":
from mimxrt import dht_readinto
elif sys.platform == "rp2":
from rp2 import dht_readinto
else:
from pyb import dht_readinto
class DHTBase:
def __init__(self, pin):
self.pin = pin
self.buf = bytearray(5)
def measure(self):
buf = self.buf
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