Merge pull request #5 from jposada202020/adding_temp_rh_resolution_properties

Adding temp rh resolution properties

Author: jposada202020

README.rst

@@ -62,11 +62,10 @@ Usage Example
 .. code-block:: python
 
     import time
-    import busio
     import board
     import adafruit_htu31d
 
-    i2c = busio.I2C(board.SCL, board.SDA)
+    i2c = board.I2C()  # uses board.SCL and board.SDA
     htu = adafruit_htu31d.HTU31D(i2c)
     print("Found HTU31D with serial number", hex(htu.serial_number))
 

adafruit_htu31d.py

@@ -9,21 +9,24 @@
 Python library for TE HTU31D temperature and humidity sensors
 
 
-* Author(s): ladyada
+* Author(s): ladyada, Jose D. Montoya.
 
 Implementation Notes
 --------------------
 
 **Hardware:**
 
-* Adafruit HTU31D breakout: https://www.adafruit.com/product/4832
+* `Adafruit HTU31 Temperature & Humidity Sensor Breakout Board
+  <https://www.adafruit.com/product/4832>`_ (Product ID: 4832)
+
 
 **Software and Dependencies:**
 
 * Adafruit CircuitPython firmware for the supported boards:
-  https://github.com/adafruit/circuitpython/releases
+  https://circuitpython.org/downloads
 
-* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
+* Adafruit's Bus Device library:
+  https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
 
 """
 
@@ -44,17 +47,48 @@
 _HTU31D_CONVERSION = const(0x40)  # Start a conversion
 _HTU31D_READTEMPHUM = const(0x00)  # Read the conversion values
 
+_HTU31D_HUMIDITY_RES = ("0.020%", "0.014%", "0.010%", "0.007%")
+_HTU31D_TEMP_RES = ("0.040", "0.025", "0.016", "0.012")
+
 
 class HTU31D:
     """
     A driver for the HTU31D temperature and humidity sensor.
 
     :param ~busio.I2C i2c_bus: The `busio.I2C` object to use. This is the only required parameter.
 
+    **Quickstart: Importing and using the device**
+
+        Here is an example of using the :class:`HTU31D` class.
+        First you will need to import the libraries to use the sensor
+
+        .. code-block:: python
+
+            import board
+            import adafruit_htu31d
+
+        Once this is done you can define your `board.I2C` object and define your sensor object
+
+        .. code-block:: python
+
+            i2c = board.I2C()  # uses board.SCL and board.SDA
+            htu = adafruit_htu31d.HTU31D(i2c)
+
+
+        Now you have access to the :attr:`temperature` and :attr:`relative_humidity`
+        attributes
+
+        .. code-block:: python
+
+            temperature = htu.temperature
+            relative_humidity = htu.relative_humidity
+
+
     """
 
     def __init__(self, i2c_bus):
         self.i2c_device = i2c_device.I2CDevice(i2c_bus, _HTU31D_DEFAULT_ADDR)
+        self._conversion_command = _HTU31D_CONVERSION
         self._buffer = bytearray(6)
         self.reset()
 
@@ -69,6 +103,7 @@ def serial_number(self):
 
     def reset(self):
         """Perform a soft reset of the sensor, resetting all settings to their power-on defaults"""
+        self._conversion_command = _HTU31D_CONVERSION
         self._buffer[0] = _HTU31D_SOFTRESET
         with self.i2c_device as i2c:
             i2c.write(self._buffer, end=1)
@@ -101,7 +136,7 @@ def relative_humidity(self):
 
     @property
     def temperature(self):
-        """The current temperature in degrees celsius"""
+        """The current temperature in degrees Celsius"""
         return self.measurements[0]
 
     @property
@@ -111,7 +146,7 @@ def measurements(self):
         temperature = None
         humidity = None
 
-        self._buffer[0] = _HTU31D_CONVERSION
+        self._buffer[0] = self._conversion_command
         with self.i2c_device as i2c:
             i2c.write(self._buffer, end=1)
 
@@ -142,6 +177,56 @@ def measurements(self):
 
         return (temperature, humidity)
 
+    @property
+    def humidity_resolution(self):
+        """The current relative humidity resolution in % rH.
+
+        Possibles values:
+
+            * "0.020%"
+            * "0.014%"
+            * "0.010%"
+            * "0.007%"
+
+        """
+
+        return _HTU31D_HUMIDITY_RES[self._conversion_command >> 4 & 3]
+
+    @humidity_resolution.setter
+    def humidity_resolution(self, value):
+        if value not in _HTU31D_HUMIDITY_RES:
+            raise ValueError(
+                "Humidity resolution must be one of: {}".format(_HTU31D_HUMIDITY_RES)
+            )
+        register = self._conversion_command & 0xCF
+        hum_res = _HTU31D_HUMIDITY_RES.index(value)
+        self._conversion_command = register | hum_res << 4
+
+    @property
+    def temp_resolution(self):
+        """The current temperature resolution in Celsius.
+
+        Possibles values:
+
+            * "0.040"
+            * "0.025"
+            * "0.016"
+            * "0.012"
+
+        """
+
+        return _HTU31D_TEMP_RES[self._conversion_command >> 2 & 3]
+
+    @temp_resolution.setter
+    def temp_resolution(self, value):
+        if value not in _HTU31D_TEMP_RES:
+            raise ValueError(
+                "Temperature resolution must be one of: {}".format(_HTU31D_TEMP_RES)
+            )
+        register = self._conversion_command & 0xF3
+        temp_res = _HTU31D_TEMP_RES.index(value)
+        self._conversion_command = register | temp_res << 2
+
     @staticmethod
     def _crc(value):
         polynom = 0x988000  # x^8 + x^5 + x^4 + 1

docs/examples.rst

@@ -6,3 +6,12 @@ Ensure your device works with this simple test.
 .. literalinclude:: ../examples/htu31d_simpletest.py
     :caption: examples/htu31d_simpletest.py
     :linenos:
+
+Setting Resolution Example
+--------------------------
+
+Show how to setup Relative Humidity and Temperature Sensor Resolutions
+
+.. literalinclude:: ../examples/htu31d_setting_resolutions.py
+    :caption: examples/htu31d_setting_resolutions.py
+    :linenos:

docs/index.rst

@@ -26,7 +26,7 @@ Table of Contents
 .. toctree::
     :caption: Related Products
 
-    Adafruit HTU31D breakout <https://www.adafruit.com/product/4832>
+    Adafruit HTU31 Temperature & Humidity Sensor Breakout Board <https://www.adafruit.com/product/4832>
 
 .. toctree::
     :caption: Other Links

examples/htu31d_setting_resolutions.py

@@ -0,0 +1,29 @@
+# SPDX-FileCopyrightText: Copyright (c) 2021 Jose David M.
+#
+# SPDX-License-Identifier: MIT
+
+import board
+import adafruit_htu31d
+
+
+# import htu31d_setting_resolutions
+i2c = board.I2C()
+htu = adafruit_htu31d.HTU31D(i2c)
+
+
+print("Temperature Resolution: ", htu.temp_resolution)
+print("Humidity Resolution: ", htu.humidity_resolution)
+
+
+# Setting the temperature resolution.
+# Possible values are "0.040", "0.025", "0.016" and "0.012"
+htu.temp_resolution = "0.016"
+
+# Setting the Relative Humidity resolution.
+# Possible values are "0.020%", "0.014%", "0.010%" and "0.007%"
+htu.humidity_resolution = "0.007%"
+
+
+# Printing the New Values
+print("Temperature Resolution: ", htu.temp_resolution)
+print("Humidity Resolution: ", htu.humidity_resolution)

examples/htu31d_simpletest.py

@@ -3,11 +3,10 @@
 # SPDX-License-Identifier: MIT
 
 import time
-import busio
 import board
 import adafruit_htu31d
 
-i2c = busio.I2C(board.SCL, board.SDA)
+i2c = board.I2C()  # uses board.SCL and board.SDA
 htu = adafruit_htu31d.HTU31D(i2c)
 print("Found HTU31D with serial number", hex(htu.serial_number))