Merge pull request #2 from ladyada/master

mini lint

Author: sommersoft

.travis.yml

@@ -23,6 +23,7 @@ deploy:
     tags: true
 
 install:
+  - pip install -r requirements.txt
   - pip install circuitpython-build-tools Sphinx sphinx-rtd-theme
   - pip install --force-reinstall pylint==1.9.2
 

README.md

@@ -13,7 +13,7 @@ Introduction
     :target: https://travis-ci.org/adafruit/Adafruit_CircuitPython_MPRLS
     :alt: Build Status
 
-.. todo:: Describe what the library does.
+CircuitPython library to support Honeywell MPRLS digital pressure sensors.
 
 Dependencies
 =============
@@ -29,7 +29,22 @@ This is easily achieved by downloading
 Usage Example
 =============
 
-.. todo:: Add a quick, simple example. It and other examples should live in the examples folder and be included in docs/examples.rst.
+.. code-block:: python
+
+	import time
+	import board
+	import busio
+	import adafruit_mprls
+
+	i2c = busio.I2C(board.SCL, board.SDA)
+
+	# Simplest use, connect to default over I2C
+	mpr = adafruit_mprls.MPRLS(i2c, psi_min=0, psi_max=25)
+
+
+	while True:
+	    print((mpr.pressure,))
+	    time.sleep(1)
 
 Contributing
 ============

README.rst

@@ -20,10 +20,10 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 """
-`Adafruit_MPRLS`
+`adafruit_mprls`
 ====================================================
 
-.. todo:: Describe what the module does
+CircuitPython library to support Honeywell MPRLS digital pressure sensors
 
 * Author(s): ladyada
 
@@ -32,21 +32,105 @@
 
 **Hardware:**
 
-.. todo:: Add links to any specific hardware product page(s), or category page(s). Use unordered list & hyperlink rST
-   inline format: "* `Link Text <url>`_"
-
 **Software and Dependencies:**
 
 * Adafruit CircuitPython firmware for the supported boards:
   https://github.com/adafruit/circuitpython/releases
-  
-.. todo:: Uncomment or remove the Bus Device and/or the Register library dependencies based on the library's use of either.
 
-# * Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
-# * Adafruit's Register library: https://github.com/adafruit/Adafruit_CircuitPython_Register
+* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
+
 """
 
 # imports
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_MPRLS.git"
+
+
+import time
+from adafruit_bus_device.i2c_device import I2CDevice
+from digitalio import Direction
+from micropython import const
+
+# pylint: disable=bad-whitespace
+_MPRLS_DEFAULT_ADDR = const(0x18)
+# pylint: enable=bad-whitespace
+
+class MPRLS:
+    """
+    Driver base for the MPRLS pressure sensor
+    :param i2c_bus: The `busio.I2C` object to use. This is the only required parameter.
+    :param int addr: The optional I2C address, defaults to 0x18
+    :param microcontroller.Pin reset_pin: Optional digitalio pin for hardware resetting
+    :param microcontroller.Pin eoc_pin: Optional digitalio pin for getting End Of Conversion signal
+    :param float psi_min: The minimum pressure in PSI, defaults to 0
+    :param float psi_max: The maximum pressure in PSI, defaults to 25
+    """
+
+    def __init__(self, i2c_bus, *, addr=_MPRLS_DEFAULT_ADDR,
+                 reset_pin=None, eoc_pin=None, psi_min=0, psi_max=25):
+        # Init I2C
+        self._i2c = I2CDevice(i2c_bus, addr)
+        self._buffer = bytearray(4)
+
+        # Optional hardware reset pin
+        if reset_pin is not None:
+            reset_pin.direction = Direction.OUTPUT
+            reset_pin.value = True
+            reset_pin.value = False
+            time.sleep(0.01)
+            reset_pin.value = True
+        time.sleep(0.005) # Start up timing
+
+        # Optional end-of-conversion pin
+        self._eoc = eoc_pin
+        if eoc_pin is not None:
+            self._eoc.direction = Direction.INPUT
+
+        if psi_min >= psi_max:
+            raise ValueError("Min PSI must be < max!")
+        self._psimax = psi_max
+        self._psimin = psi_min
+        # That's pretty much it, there's no ID register :(
+
+    @property
+    def pressure(self):
+        """The measured pressure, in hPa"""
+        return self._read_data()
+
+
+    def _read_data(self):
+        """Read the status & 24-bit data reading"""
+        self._buffer[0] = 0xAA
+        self._buffer[1] = 0
+        self._buffer[2] = 0
+        with self._i2c as i2c:
+            # send command
+            i2c.write(self._buffer, end=3)
+            # ready busy flag/status
+            while True:
+                # check End of Convert pin first, if we can
+                if self._eoc is not None:
+                    if self._eoc.value:
+                        break
+                # or you can read the status byte
+                i2c.readinto(self._buffer, end=1)
+                if not self._buffer[0] & 0x20:
+                    break
+            # no longer busy!
+            i2c.readinto(self._buffer, end=4)
+
+        # check other status bits
+        if self._buffer[0] & 0x01:
+            raise RuntimeError("Internal math saturation")
+        if self._buffer[0] & 0x04:
+            raise RuntimeError("Integrity failure")
+
+        # All is good, calculate the PSI and convert to hPA
+        raw_psi = (self._buffer[1] << 16) | (self._buffer[2] << 8) | self._buffer[3]
+        # use the 10-90 calibration curve
+        psi = (raw_psi - 0x19999A) * (self._psimax-self._psimin)
+        psi /= 0xE66666 - 0x19999A
+        psi += self._psimin
+        # convert PSI to hPA
+        return psi * 68.947572932

adafruit_mprls.py

@@ -20,7 +20,7 @@
 # Uncomment the below if you use native CircuitPython modules such as
 # digitalio, micropython and busio. List the modules you use. Without it, the
 # autodoc module docs will fail to generate with a warning.
-# autodoc_mock_imports = ["digitalio", "busio"]
+autodoc_mock_imports = ["digitalio", "micropython"]
 
 
 intersphinx_mapping = {'python': ('https://docs.python.org/3.4', None),'BusDevice': ('https://circuitpython.readthedocs.io/projects/busdevice/en/latest/', None),'CircuitPython': ('https://circuitpython.readthedocs.io/en/latest/', None)}

docs/conf.py

@@ -23,15 +23,9 @@ Table of Contents
 .. toctree::
     :caption: Tutorials
 
-.. todo:: Add any Learn guide links here. If there are none, then simply delete this todo and leave
-    the toctree above for use later.
-
 .. toctree::
     :caption: Related Products
 
-.. todo:: Add any product links here. If there are none, then simply delete this todo and leave
-    the toctree above for use later.
-
 .. toctree::
     :caption: Other Links
 

docs/index.rst

@@ -0,0 +1,22 @@
+import time
+import board
+import busio
+import adafruit_mprls
+
+i2c = busio.I2C(board.SCL, board.SDA)
+
+# Simplest use, connect to default over I2C
+mpr = adafruit_mprls.MPRLS(i2c, psi_min=0, psi_max=25)
+
+# You can also specify both reset and eoc pins
+"""
+import digitalio
+reset = digitalio.DigitalInOut(board.D5)
+eoc = digitalio.DigitalInOut(board.D6)
+mpr = adafruit_mprls.MPRLS(i2c, eoc_pin=eoc, reset_pin=reset,
+                           psi_min=0, psi_max=25)
+"""
+
+while True:
+    print((mpr.pressure,))
+    time.sleep(1)

examples/mprls_simpletest.py

@@ -1 +1,2 @@
+Adafruit-Blinka
 adafruit-circuitpython-busdevice