initial DHT lib supports DHT11 and DHT22 devices

CODE_OF_CONDUCT.md

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+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at support@adafruit.com. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/

README.rst

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+
+Introduction
+============
+
+.. image:: https://readthedocs.org/projects/adafruit-circuitpython-dhtlib/badge/?version=latest
+    :target: https://circuitpython.readthedocs.io/projects/dhtlib/en/latest/
+    :alt: Documentation Status
+
+.. image :: https://badges.gitter.im/adafruit/circuitpython.svg
+    :target: https://gitter.im/adafruit/circuitpython?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge
+    :alt: Gitter
+
+TODO
+
+Dependencies
+=============
+This driver depends on:
+
+* `Adafruit CircuitPython <https://github.com/adafruit/circuitpython>`_
+* `Bus Device <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>`_
+* `Register <https://github.com/adafruit/Adafruit_CircuitPython_Register>`_
+
+Please ensure all dependencies are available on the CircuitPython filesystem.
+This is easily achieved by downloading
+`the Adafruit library and driver bundle <https://github.com/adafruit/Adafruit_CircuitPython_Bundle>`_.
+
+Usage Example
+=============
+
+Basics
+------
+
+Of course, you must import the library to use it:
+
+.. code:: python
+
+    import adafruit_dhtlib
+
+The DHT type devices use single data wire, so import the board pin
+
+.. code::python
+
+    from board import <pin>
+
+Now, to initialize the DHT11 device:
+
+.. code:: python
+
+    dhtDevice = dht.DHT11(<pin>)
+
+OR initialize the DHT22 device:
+
+.. code:: python
+
+    dhtDevice = dht.DHT22(<pin>)
+
+Read temperature and humidity
+----------------------------
+
+First you must request data from the device by calling method measure(). 
+If success is equal to 0 then data is ready
+
+.. code::python
+
+    success = device.measure()
+
+Get the temperure value and the humidity value
+
+.. code::python
+
+    temperature = device.temperature
+    humidity = device.humidity
+
+
+Contributing
+============
+
+Contributions are welcome! Please read our `Code of Conduct
+<https://github.com/adafruit/Adafruit_CircuitPython_dhtlib/blob/master/CODE_OF_CONDUCT.md>`_
+before contributing to help this project stay welcoming.
+
+API Reference
+=============
+
+.. toctree::
+   :maxdepth: 2
+
+   api

adafruit_dhtlib.py

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+# The MIT License (MIT)
+#
+# Copyright (c) 2017 Mike McWethy for Adafruit Industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""
+:mod:`adafruit_dhtlib`
+====================================================
+
+TODO(description)
+
+* Author(s): Mike McWethy
+"""
+
+import pulseio
+import array
+import time
+
+
+class dht_base:
+    """ base support for DHT11 and DHT22 devices
+    """
+        
+    hiLev = 51    
+    
+    def __init__(self, dht11, pin, trigWait):
+        """
+        :param boolean dht11: devide type.  ==True DHT11 ==False DHT22
+        :param ~board.Pin pin: digital pin used for communication 
+        :param int trigWait: length of time to hold trigger in LOW state (microseconds)
+        """
+        self.dht11 = dht11
+        self.pin = pin
+        self.trigWait = trigWait
+        
+
+    def plsToBinary(self,r, s, l):
+        """ PulsesToBinary takes r, a list of transition times, and converts
+        them to a 1's or 0's.  The r array contains the transition times.
+        r starts with a low transition time followed by a high transistion time.
+        then a low followed by a high and so on.  The low transition times are 
+        ignored.  Only the high transistion times are used.  If the high
+        transistion time is greater than hiLev, that counts as a bit=1, if the 
+        high transition time is less that hiLev, that counts as a bit=0.
+
+        s is the starting index in r to start converting
+
+        l is the last index + 1 in r to end converting
+
+        Returns an integer containing the converted 1 and 0 bits
+        """        
+        # humidity 16 bits
+        i = 0
+        hiSig = False
+        for e in range(s,l):
+            if hiSig:
+                b =0
+                if r[e] > self.hiLev:
+                    b = 1
+                i = i<<1 | b
+            hiSig = not hiSig
+
+        return i
+
+    def getPulses(self):
+        """ getPulses implements the commumication protcol for
+        DHT11 and DHT22 type devices.  It send a start signal
+        of a specific length and listens and measures the 
+        return signal lengths.
+
+        pin is a board pin connected to the data pin of the device
+
+        trigWait is the amount of time to hold the start signal
+        in the low state.  This value varies based on the devide type. 
+
+        return r (array.array uint16) contains alternating high and low
+        transition times starting with a low transition time.  Normally
+        r will have 81 elements for the DHT11/22 type devices.      
+        """
+        r = array.array('H')
+        t = time.monotonic()
+
+        # create the PulseIn object using context manager
+        with pulseio.PulseIn(self.pin,81,True) as pls:
+
+            # The DHT type device use a specialize 1-wire protocol
+            # The microprocess first sends a LOW signal for a
+            # specific length of time.  Then the device send back a
+            # series HIGH and LOW signals.  The length the signals
+            # determine the device values.
+            pls.pause()
+            pls.clear()
+            pls.resume(self.trigWait)
+
+            # loop until we get the return pulse we need or
+            # time out after 2 seconds
+            while True: 
+                if len(pls)>=80:
+                    break
+                if time.monotonic()-t > 2.0: # time out after 2 seconds
+                    break
+    
+            pls.pause()
+            while len(pls)>0:
+                r.append(pls.popleft())
+            pls.resume()
+
+        return r
+
+    def measure(self):
+        """ measure runs the communications to the DHT11/22 type device.
+            if successful, the class properties tempature and humidity will
+            return the reading returned from the device.
+
+            Returns an integer.  ==0 for successful, ==-1 for checksum failure 
+            (try again), ==-2 for insuffcient data return from the device (try 
+            again)
+        """       
+        success = None
+
+        r = self.getPulses() 
+        ##print(r)
+
+        if len(r)>=80:
+            bits = array.array('B')
+            for b in range(0,80,16):
+                bits.append(self.plsToBinary(r,b,b+16))
+            #print(bits)
+            
+            # humidity 16 bits
+            hum = 0
+            if self.dht11:
+                self.hum = bits[0]
+            else:
+                self.hum = ((bits[0]<<8) | bits[1]) / 10
+        
+            # tempature 16 bits
+            self.temp = 0
+            if self.dht11:
+                self.temp = bits[2]
+            else:
+                self.temp = ((bits[2]<<8) | bits[3]) / 10
+            
+            # calc  checksum
+            ckSum = 0
+            for b in bits[0:4]:
+                ckSum += b
+
+            if ckSum & 0xff == bits[4]:
+                #checksum matches
+                # report temp and humidity
+                success = 0
+                #print("Temp: {} C Humidity: {}% ".format(temp, hum))
+                
+            else:
+                success = -1
+                #print("checksum did not match. Temp: {} Hum: {} Checksum:{}".format(temp,hum,bits[4]))
+                
+        else:
+            success = -2
+            #print("did not get a full return.  number returned was: {}".format(len(r)))
+
+        return success
+
+    @property
+    def temperature(self):
+        return self.temp
+
+    @property
+    def humidity(self):
+        return self.hum
+
+class DHT11(dht_base):
+    """ Support for DHT11 device.  
+
+        :param ~board.Pin pin: digital pin used for communication 
+    """
+    def __init__(self, pin):
+        super().__init__(True, pin, 18000)
+
+
+class DHT22(dht_base):
+    """ Support for DHT22 device.  
+
+        :param ~board.Pin pin: digital pin used for communication 
+    """
+    def __init__(self, pin):
+        super().__init__(False, pin, 1000)

api.rst

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+
+.. If you created a package, create one automodule per module in the package.
+
+.. automodule:: adafruit_dhtlib
+   :members:

conf.py

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+# -*- coding: utf-8 -*-
+
+import os
+import sys
+sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration ------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.autodoc',
+    'sphinx.ext.intersphinx',
+    'sphinx.ext.viewcode',
+]
+
+intersphinx_mapping = {'python': ('https://docs.python.org/3.4', None),'BusDevice': ('https://circuitpython.readthedocs.io/projects/bus_device/en/latest/', None),'Register': ('https://circuitpython.readthedocs.io/projects/register/en/latest/', None),'CircuitPython': ('https://circuitpython.readthedocs.io/en/latest/', None)}
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+source_suffix = '.rst'
+
+# The master toctree document.
+master_doc = 'README'
+
+# General information about the project.
+project = u'Adafruit DHTLIB Library'
+copyright = u'2017 Mike McWethy'
+author = u'Mike McWethy'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = u'1.0'
+# The full version, including alpha/beta/rc tags.
+release = u'1.0'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This patterns also effect to html_static_path and html_extra_path
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+#
+default_role = "any"
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#
+add_function_parentheses = True
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    try:
+        import sphinx_rtd_theme
+        html_theme = 'sphinx_rtd_theme'
+        html_theme_path = [sphinx_rtd_theme.get_html_theme_path(), '.']
+    except:
+        html_theme = 'default'
+        html_theme_path = ['.']
+else:
+    html_theme_path = ['.']
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'AdafruitDHTLIBLibrarydoc'
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+     # The paper size ('letterpaper' or 'a4paper').
+     #
+     # 'papersize': 'letterpaper',
+
+     # The font size ('10pt', '11pt' or '12pt').
+     #
+     # 'pointsize': '10pt',
+
+     # Additional stuff for the LaTeX preamble.
+     #
+     # 'preamble': '',
+
+     # Latex figure (float) alignment
+     #
+     # 'figure_align': 'htbp',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    (master_doc, 'AdafruitDHTLIBLibrary.tex', u'Adafruit DHTLIB Library Documentation',
+     author, 'manual'),
+]
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'adafruitDHTLIBlibrary', u'Adafruit DHTLIB Library Documentation',
+     [author], 1)
+]
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'AdafruitDHTLIBLibrary', u'Adafruit DHTLIB Library Documentation',
+     author, 'AdafruitDHTLIBLibrary', 'One line description of project.',
+     'Miscellaneous'),
+]

example.py

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+
+
+
+# example of reading temperate and humidity from a DHT device
+# and displaying results to the serial port and a 8 digit 7-segment display
+import time
+import dht
+from board import D2
+
+from  adafruit_max7219 import bcddigits
+from board import TX, RX, A2
+import busio
+import digitalio
+
+clk = RX
+din = TX
+cs = digitalio.DigitalInOut(A2)
+spi = busio.SPI(clk, MOSI=din)
+display = bcddigits.BCDDigits(spi, cs, nDigits=8)
+display.brightness(5)
+print(D2)
+device = dht.DHT22(D2)
+
+while True:
+    success = device.measure()
+
+    if success == 0:
+        print("Temp: {:.1f} F Humidity: {}% ".format(device.temperature*9/5+32, device.humidity))
+        display.clear_all()
+        display.show_str(0,'{:5.1f}{:5.1f}'.format(device.temperature*9/5+32,device.humidity))
+        display.show()
+    elif success == -1:
+        print("The data checksum did not validate.  Try again.")
+    elif success == -2:
+        print("The device did not return enough data. Try again.")
+    else:
+        print("Something else bad happened: Error {}".format(success))
+
+    if success == 0:
+        time.sleep(2.0) 
+    else:
+        time.sleep(0.4)
+
+
+
+    

readthedocs.yml

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+requirements_file: requirements.txt
+