v2.1.2

• Bug fixes
  • Fix compilation when Erlang has been installed to a directory with spaces

v2.1.1

• Changes
  • Show if GPIO number remapping is happening for AM335x platforms via backend_info/0.
  • Drop support for Elixir 1.11 and 1.12.

v2.1.0

• Changes

  • Show backend options via backend_info/0 so that it's possible to see
    whether you're using CDev test mode or not.

  iex> Circuits.GPIO.backend_info()
  %{name: {Circuits.GPIO.CDev, [test: true]}, pins_open: 0}

v2.0.2

• Bug fixes

  • Remove lazy NIF loading. There's an unexplained segfault in a small example
    program that uses the same strategy. Even though it wasn't reproduceable
    here, it's not worth the risk. Thanks to @pojiro for investigating.

• Changes

  • Add example Livebook. Thanks to @mnishiguchi.

v1.2.2

• Bug fixes
  • Remove lazy NIF loading. There's an unexplained segfault in a small example
    program that uses the same strategy. Even though it wasn't reproduceable
    here, it's not worth the risk. Thanks to @pojiro for investigating.

v2.0.1

• Bug fixes
  • Fix race condition when loading NIF. If two processes caused the NIF to be
    loaded at the same time, then it was possible for one to return an error.
  • Remove tracking of the number of open pins from the cdev backend to not need
    to synchronize access to the count. This feature really was only used for
    the unit tests.

v1.2.1

• Bug fixes
  • Fix race condition when loading NIF. If two processes caused the NIF to be
    loaded at the same time, one might return an error. This issue was
    introduced in v1.2.0.

v2.0.0

This is a major update to Circuits.GPIO that modernizes the API, restricts usage
to Nerves and Linux, and updates the Linux/Nerves backend to the Linux GPIO cdev
interface.

It is mostly backwards compatible with Circuits.GPIO v1. Please see PORTING.md
for upgrade instructions.

• New features

  • Support alternative backends for different operating systems or for
    simulated hardware. The Linux cdev backend can be compiled out.

  • Circuits.GPIO.open/3 is much more flexible in how GPIOs are identified.
    Specifying GPIOs by number still works, but it's now possible to specify
    GPIOs by string labels and by tuples that contain the GPIO controller name
    and index. See t:gpio_spec/0 and the README.md for details.

  • List out available GPIOs with Circuits.GPIO.enumerate/0. Other helper
    functions are available for getting more information about each GPIO too.

  • Specify pull modes in general rather than only Raspberry Pis on Linux and
    Nerves

  • Easily do one-off reads and writes with Circuits.GPIO.read_one/2 and
    Circuits.GPIO.write_one/3

  • Improved performance on Nerves and Linux; kernel-applied timestamping of
    GPIO input events

  • Add Circuits.GPIO.Diagnostics to automate runtime testing

• Changes

  • More consistent error returns. Unexpected errors return {:errno, value}
    tuples to help correlate errors to low level docs
  • Deferred loading of the NIF to simplify debugging of GPIO backends.
    Segfaults crash on first use of Circuits.GPIO rather than on load.

v1.2.0

• Changes
  • Add workaround to GPIO pin numbering change on TI AM335x platforms (like the
    BBB) that happened between Linux 5.10 and 5.15. Circuits.GPIO will remap the
    pins automatically so the number is consistent with the way it's been for
    years and the way that most online docs talk about it. E.g., GPIO number is
    the pin bank times 32 plus the pin offset in the bank.
  • Defer NIF loading until opening the first GPIO. This is a minor optimization
    to delay shared library load time and issue to a little later in boot.

v1.1.0

• Changes
  • Remove Erlang convenience functions since no one used them
  • Require Elixir 1.10 or later. Previous versions probably work, but won't be
    supported. This opens up the possibility of using Elixir 1.10+ features in
    future releases.