zephyr/samples/sensor/mcp9808
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 samples: sensor : mcp9808: check return value 2018-06-01 14:41:42 -05:00
CMakeLists.txt cmake: Prepend 'cmake_minimum_required()' into 'app' build scripts 2018-08-15 04:06:50 -07:00
README.rst doc: change UTF-8 chars to sphinx inline replaces 2017-06-16 07:35:11 -05:00
prj.conf samples: mcp9808: Fix CONFIG_MCP9808_TRIGGER_GLOBAL_THREAD assignment 2018-05-24 09:21:32 -04:00
sample.yaml samples: mcp9808: fix dependencies and test cleanup 2017-12-28 20:24:29 -05:00

README.rst

.. _mcp9808-sample:

MCP9808 Temperature Sensor
##########################

Overview
********

Sample application that periodically reads temperature from the MCP9808 sensor.


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

The MCP9808 digital temperature sensor converts temperatures between -20 |deg|
C and +100 |deg| C to a digital word with |plusminus| 0.5 |deg| C (max.)
accuracy. It is I2C compatible and
supports up to 16 devices on the bus. We do not require pullup resistors on the
data or clock signals as they are already installed on the breakout board.

The MCP9808 is available in a discrete component form but it is much easier to
use it mounted on a breakout board. We used the Adafruit breakout board.

- `MCP9808 Sensor`_

This sample uses the sensor APIs and the provided driver for the MCP9808 sensor.

Wiring
*******

The MCP9808 requires 2 wires for the I2C bus plus power and ground. The power
can be either 5V or 3.3V.

We connect the Data and clock wires to Analog ports A4 and A5 which is the I2C
pins on Arduino compatible boards.

In this hookup we are only connecting one device to one of the supported boards.
It reads the temperature and displays it on the console.


References
***********

- http://www.microchip.com/wwwproducts/en/en556182


.. _`MCP9808 Sensor`: https://www.adafruit.com/product/1782