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-rw-r--r--esp8266/scripts/dht.py32
1 files changed, 32 insertions, 0 deletions
diff --git a/esp8266/scripts/dht.py b/esp8266/scripts/dht.py
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+++ b/esp8266/scripts/dht.py
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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