Add Custom Si7201 Lib

Si7201 temperature and relative humidity sensor class, with callable properties

si7201.py

@@ -0,0 +1,40 @@
+"""Library for interacting with Si7201 Temperature & Humidity Sensor."""
+
+import smbus2
+from time import sleep
+
+
+class Si7201:
+    def __init__(self, i2cBus, i2cAddress=0x40):
+        self.i2c = i2cBus
+        self.addr = i2cAddress
+        i2cBus.pec = True  # enable smbus2 Packet Error Checking
+
+    @property
+    def temperature(self, decimals=1):
+        """Measured temperature in degrees Celsius, with configurable decimal places, default 1."""
+        measure_temp = smbus2.i2c_msg.write(self.addr, [0xF3])
+        read_temp = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(measure_temp)
+        sleep(0.1)
+        self.i2c.i2c_rdwr(read_temp)
+        temp_code = int.from_bytes(read_temp.buf[0] + read_temp.buf[1], "big")
+        temp = round(((175.72 * temp_code) / 65536 - 46.85), decimals)
+        return temp
+
+    @property
+    def humidity(self, decimals=1):
+        """Measured relative humidity in percent, with configurable decimal places, default 1."""
+        measure_hum = smbus2.i2c_msg.write(self.addr, [0xF5])
+        read_rh = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(measure_hum)
+        sleep(0.1)
+        self.i2c.i2c_rdwr(read_rh)
+        rh_code = int.from_bytes(read_rh.buf[0] + read_rh.buf[1], "big")
+        hum = round((125 * rh_code) / 65536 - 6.0, decimals)
+        return hum
+
+    def reset(self):
+        """Reset the sensor."""
+        resetcmd = smbus2.i2c_msg.write(self.addr, [0xFE])
+        self.i2c.i2c_rdwr(resetcmd)