Add Custom TMP006 Lib

TMP006 IR temperature sensor class, with callable properties

tmp006.py

@@ -0,0 +1,122 @@
+"""Library for interacting with TMP006 Thermopile (IR Temperature) Sensor."""
+
+import smbus2
+from time import sleep
+
+# Pointer Register Locations
+_REG_VOBJ = bytes([0x00])
+_REG_TAMB = bytes([0x01])
+_REG_CNFG = bytes([0x02])
+_REG_M_ID = bytes([0xFE])
+_REG_D_ID = bytes([0xFF])
+# Configuration Flags
+_MODE_ON = bytes([0x70])
+SAMPLERATE_4HZ = bytes([0x00])
+SAMPLERATE_2HZ = bytes([0x02])
+SAMPLERATE_1HZ = bytes([0x04])
+SAMPLERATE_0_5HZ = bytes([0x06])
+SAMPLERATE_0_25HZ = bytes([0x08])
+_DRDY_EN = bytes([0x01])
+
+
+class TMP006:
+    def __init__(self, i2cBus, i2cAddress=0x40, samplerate=SAMPLERATE_1HZ):
+        self.i2c = i2cBus
+        self.addr = i2cAddress
+        self.samplerate = samplerate
+        i2cBus.pec = True  # enable smbus2 Packet Error Checking
+        self.config = bytes([0x00, 0x00])
+        self.config = (
+            self.config[0] | samplerate[0] | _MODE_ON[0] | _DRDY_EN[0] + self.config[1]
+        )
+        ptrConfig = smbus2.i2c_msg.write(self.addr, _REG_CNFG)
+        writeConfig = smbus2.i2c_msg.write(self.addr, self.config)
+        self.i2c.i2c_rdwr(ptrConfig, writeConfig)
+
+    @property
+    def temperature(self) -> float:
+        Vobj = self.vObject()
+        Tdie = self.tAmbient()
+        # Values for Calculations
+        S0 = 6.4e-14  # Calibration Factor TODO: Calibrate
+        a1 = 1.75e-3
+        a2 = -1.678e-5
+        Tref = 298.15
+        b0 = -2.94e-5
+        b1 = -5.7e-7
+        b2 = 4.63e-9
+        c2 = 13.4
+        # Calculate Sensitivity of Thermopile
+        S = S0 * (1 + a1 * (Tdie - Tref) + a2 * ((Tdie - Tref) ** 2))
+        # Calculate Coltage offset due to package thermal resistance
+        Voffset = b0 + b1 * (Tdie - Tref) + b2 * ((Tdie - Tref) ** 2)
+        # Calculate Seebeck coefficients
+        fVobj = (Vobj - Voffset) + c2 * ((Vobj - Voffset) ** 2)
+        # Calculate object temperature in Kelvin
+        Tobj = (Tdie**4 + (fVobj / S)) ** 0.25
+        # Convert from Kelvin to Celsius
+        return Tobj - 273.15
+
+    @property
+    def active(self) -> bool:
+        """Check if Sensor is powered on."""
+        ptrPower = smbus2.i2c_msg.write(self.addr, _REG_CNFG)
+        power = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(ptrPower, power)
+        return power.buf[0] & _MODE_ON[0] != 0
+
+    @active.setter
+    def active(self, value: bool):
+        """Set the sensor to active or inactive."""
+        if value:
+            ptrPower = smbus2.i2c_msg.write(self.addr, _REG_CNFG)
+            power = smbus2.i2c_msg.read(self.addr, 2)
+            self.i2c.i2c_rdwr(ptrPower, power)
+            newPower = power.buf[0] | _MODE_ON[0] + power.buf[1]
+            updatePower = smbus2.i2c_msg.write(self.addr, newPower)
+            self.i2c.i2c_rdwr(ptrPower, updatePower)
+        else:
+            ptrPower = smbus2.i2c_msg.write(self.addr, _REG_CNFG)
+            power = smbus2.i2c_msg.read(self.addr, 2)
+            self.i2c.i2c_rdwr(ptrPower, power)
+            newPower = power.buf[0] & ~_MODE_ON[0] + power.buf[1]
+            updatePower = smbus2.i2c_msg.write(self.addr, newPower)
+            self.i2c.i2c_rdwr(ptrPower, updatePower)
+
+    def vObject(self) -> float:
+        """Reading from Sensor Voltage Register in Volts"""
+        ptrVobject = smbus2.i2c_msg.write(self.addr, _REG_VOBJ)
+        readVobject = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(ptrVobject, readVobject)
+        scaledVoltage = int.from_bytes(
+            readVobject.buf[0] + readVobject.buf[1], byteorder="big", signed=True
+        )
+        return round(scaledVoltage * 156.25e-9, 1)
+        # convert to Volts (156.25nV per LSB * 1e-9 for scaling from nV to Volts)
+
+    def tAmbient(self) -> float:
+        """Reading from Ambient Temperature Register in Degrees Celsius"""
+        ptrTambient = smbus2.i2c_msg.write(self.addr, _REG_TAMB)
+        readTambient = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(ptrTambient, readTambient)
+        scaledTemp = int.from_bytes(
+            readTambient.buf[0] + readTambient.buf[1], byteorder="big", signed=True
+        )
+        return round(scaledTemp * 0.0078125, 1)
+        # convert to degrees Celsius (1/32 for scaling * 1/4 for 2 bit shift)
+
+    @property
+    def manID(self) -> bytes:
+        """Sensor manufacturer ID"""
+        ptrManID = smbus2.i2c_msg.write(self.addr, _REG_M_ID)
+        readManID = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(ptrManID, readManID)
+        return readManID.buf[0] + readManID.buf[1]
+
+    @property
+    def devID(self) -> bytes:
+        """Sensor device ID"""
+        ptrDevID = smbus2.i2c_msg.write(self.addr, _REG_D_ID)
+        readDevID = smbus2.i2c_msg.read(self.addr, 2)
+        self.i2c.i2c_rdwr(ptrDevID, readDevID)
+        return readDevID.buf[0] + readDevID.buf[1]