esp8266: Add dht.py script for high-level control of DHT11/DHT22 sensor.

TODO: should go in a more port-neutral place, like drivers/dht, but at the
moment in relies on specific esp module.
This commit is contained in:
Damien George 2016-05-26 17:13:03 +01:00
parent 45f3416816
commit 7ebfe09fbd
1 changed files with 32 additions and 0 deletions

32
esp8266/scripts/dht.py Normal file
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# 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