First version of I2CDevice

Author: tannewt

.gitignore

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+*.mpy

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 [email protected]. 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/

LICENSE

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+MIT License
+
+Copyright (c) 2016 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.

README.md

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+# Adafruit MicroPython BusDevice
+
+The `I2CDevice` and `SPIDevice` helper classes make managing transaction state
+on a bus easy. For example, they manage locking the bus to prevent other
+concurrent access. For SPI devices, it manages the chip select and protocol
+changes such as mode. For I2C, it manages the device address.

adafruit_bus_device/i2c_device.py

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+# The MIT License (MIT)
+#
+# Copyright (c) 2016 Scott Shawcroft 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.
+
+class I2CDevice:
+    """
+    Represents a single I2C device and manages locking the bus and the device
+    address.
+
+    :param I2C i2c: The I2C bus the device is on
+    :param int device_address: The 7 bit device address
+
+    Example::
+
+        import nativeio
+        from board import *
+        from adafruit_bus_device.i2c_device import I2CDevice
+
+        with nativeio.I2C(SCL, SDA) as i2c:
+            device = I2CDevice(i2c, 0x70)
+            bytes_read = bytearray(4)
+            with device:
+                device.readfrom_into(bytes_read)
+            # A second transaction
+            with device:
+                device.writeto(bytes_read)
+    """
+    def __init__(self, i2c, device_address):
+        self.i2c = i2c
+        self.device_address = device_address
+
+    def readfrom_into(self, buf, **kwargs):
+        """
+        Read into ``buf`` from the device. The number of bytes read will be the
+        length of ``buf``.
+
+        If ``start`` or ``end`` is provided, then the buffer will be sliced
+        as if ``buf[start:end]``. This will not cause an allocation like
+        ``buf[start:end]`` will so it saves memory.
+
+             :param int address: 7-bit device address
+             :param bytearray buffer: buffer to write into
+             :param int start: Index to start writing at
+             :param int end: Index to write up to but not include
+        """
+        self.i2c.readfrom_into(self.device_address, buf, **kwargs)
+
+    def writeto(self, buf, **kwargs):
+        """
+        Write the bytes from ``buffer`` to the device. Transmits a stop bit if
+        ``stop`` is set.
+
+        If ``start`` or ``end`` is provided, then the buffer will be sliced
+        as if ``buffer[start:end]``. This will not cause an allocation like
+        ``buffer[start:end]`` will so it saves memory.
+
+          :param bytearray buffer: buffer containing the bytes to write
+          :param int start: Index to start writing from
+          :param int end: Index to read up to but not include
+          :param bool stop: If true, output an I2C stop condition after the
+                            buffer is written
+        """
+        self.i2c.writeto(self.device_address, buf, **kwargs)
+
+    def __enter__(self):
+        while not self.i2c.try_lock():
+            pass
+        return self
+
+    def __exit__(self, *exc):
+        self.i2c.unlock()
+        return False