zephyr/samples/display/grove_display
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
README.rst
prj.conf
sample.yaml

README.rst

.. _grove-lcd-sample:

Grove LCD
#########

Overview
********

This sample displays an incrementing counter through the Grove LCD, with
changing backlight.

Requirements
************

To use this sample, the following hardware is required:

* Arduino 101 or Quark D2000 Devboard
* `Grove LCD module`_
* `Grove Base Shield`_ [Optional]

Wiring
******

You will need to connect the Grove LCD via the Grove shield onto a board that
supports Arduino shields.

On some boards you will need to use 2 pull-up resistors (10k Ohm) between the
SCL/SDA lines and 3.3V.

.. note::

   The I2C lines on Quark SE Sensor Subsystem does not have internal pull-up, so
   external one is required.

Take note that even though SDA and SCL are connected to a 3.3V power source, the
Grove LCD VDD line needs to be connected to the 5V power line, otherwise
characters will not be displayed on the LCD (3.3V is enough to power just the
backlight).


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

This sample should work on any board that has I2C enabled and has an Arduino
shield interface. For example, it can be run on the Quark D2000 DevBoard as
described below:

.. zephyr-app-commands::
   :zephyr-app: samples/grove/lcd
   :board: quark_d2000_crb
   :goals: flash
   :compact:

.. _Grove Base Shield: http://wiki.seeedstudio.com/wiki/Grove_-_Base_Shield
.. _Grove LCD module: http://wiki.seeed.cc/Grove-LCD_RGB_Backlight/