zephyr/samples/boards/microbit/sound
Sebastian Bøe 55ee53ce91 cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts
Prepend the text 'cmake_minimum_required(VERSION 3.8.2)' into the
application and test build scripts.

Modern versions of CMake will spam users with a deprecation warning
when the toplevel CMakeLists.txt does not specify a CMake
version. This is documented in bug #8355.

To resolve this we include a cmake_minimum_required() line into the
toplevel build scripts. Additionally, cmake_minimum_required is
invoked from within boilerplate.cmake. The highest version will be
enforced.

This patch allows us to afterwards change CMake policy CMP000 from OLD
to NEW which in turn finally rids us of the verbose warning.

The extra boilerplate is considered more acceptable than the verbosity
of the CMP0000 policy.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
2018-08-15 04:06:50 -07:00
..
src
CMakeLists.txt cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts 2018-08-15 04:06:50 -07:00
README.rst
prj.conf
sample.yaml

README.rst

.. _microbit_sound:

BBC micro:bit sound
###################

Overview
********

This is simple example demonstrating how to use a piezo buzzer connected
to port P0 on the edge connector of the BBC micro:bit board. Note that
the buzzer is not part of the main micro:bit board, rather it it needs
to be separately acquired and connected. A well working example is the
MI:Power board that has a piezo buzzer in addition to a coin-cell
battery. Resellers of this board can be fairly easily found using online
search.

Building
********

The sample can be built as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/boards/microbit/sound
   :board: bbc_microbit
   :goals: build
   :compact:

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

This sample outputs sounds through a connected piezo buzzer based on
button presses of the two main buttons. For each press the current
output frequency will be printed on the 5x5 LED display.