zephyr

History

Gerard Marull-Paretas 3f2c2d4130 drivers: spi: make SPI dt-spec macros compatible with C++ As of today it is not possible to use SPI dt-spec macros in C++, something known and documented. The main reason is because `cs` property is initialized using a compound literal, something not supported in C++. This PR takes another approach, that is to not make `cs` a pointer but a struct member. This way, we can perform a regular initialization, at the cost of using extra memory for unused delay/pin/flags if `cs` is not used. Fixes #56572 Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>		2023-04-24 21:29:55 +02:00
..
boards	samples: spi_bitbang: Use gpio_loopback pins for MOSI and MISO	2023-01-20 13:28:27 +01:00
src	drivers: spi: make SPI dt-spec macros compatible with C++	2023-04-24 21:29:55 +02:00
CMakeLists.txt	cmake: Update cmake_minimum_required to 3.20.0	2022-07-04 10:18:45 +02:00
prj.conf
README.rst
sample.yaml

README.rst

.. _spi-bitbang-sample:

SPI-Bitbang Sample
####################

Overview
********

This sample demonstrates using the bitbang SPI driver. The bitbang driver can
be useful for devices which use a non multiple of 8 word size, for example some
LCDs which have an extra cmd/data bit.

This sample loops through some different spi transfer configurations.


Building and Running
********************

The application will build only for a target that has a :ref:`devicetree
<dt-guide>` entry with :dtcompatible:`zephyr,spi-bitbang` as a compatible.

You can connect the MISO and MOSI pins with a wire to provide a basic loopback
test for receive data.

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/spi_bitbang
   :board: nrf52840dk_nrf52840
   :goals: build flash
   :compact:

Sample Output
=============

.. code-block:: console

  *** Booting Zephyr OS build zephyr-v2.6.0-2939-g1882b95b42e2  ***
  basic_write_9bit_words; ret: 0
    wrote 0101 00ff 00a5 0000 0102
  9bit_loopback_partial; ret: 0
   tx (i)  : 0101 0102
   tx (ii) : 0003 0004 0105
   rx (ii) : 0003 0004 0105
  basic_write_9bit_words; ret: 0
   wrote 0101 00ff 00a5 0000 0102
  9bit_loopback_partial; ret: 0
   tx (i)  : 0101 0102
   tx (ii) : 0003 0004 0105
   rx (ii) : 0003 0004 0105
  basic_write_9bit_words; ret: 0
   wrote 0101 00ff 00a5 0000 0102
  9bit_loopback_partial; ret: 0
   tx (i)  : 0101 0102
   tx (ii) : 0003 0004 0105
   rx (ii) : 0003 0004 0105