micropython/drivers: Move "dht" sensor driver from main repo.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

micropython/drivers/sensor/dht/dht.py

@@ -0,0 +1,46 @@
+# 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
+elif sys.platform == "pyboard":
+    from pyb import dht_readinto
+else:
+    from machine 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

micropython/drivers/sensor/dht/manifest.py

@@ -0,0 +1 @@
+module("dht.py", opt=3)