zephyr/samples/drivers/dac
Kieran Mackey 38ed9c885e drivers: dac: added driver for Microchip MCP4725
The MCP4725 is a single channel 12 bit DAC. It is controlled via I2C.

Signed-off-by: Kieran Mackey <kieran.mackey@lairdconnect.com>
2021-05-06 11:07:33 -05:00
..
boards drivers: dac: added driver for Microchip MCP4725 2021-05-06 11:07:33 -05:00
src samples: dac: move HW config to /zephyr,user 2021-05-05 20:46:43 +02:00
CMakeLists.txt samples: make find_package(Zephyr...) REQUIRED 2020-05-29 10:47:25 +02:00
prj.conf
README.rst drivers: dac: added driver for Microchip MCP4725 2021-05-06 11:07:33 -05:00
sample.yaml drivers: dac: added driver for Microchip MCP4725 2021-05-06 11:07:33 -05:00

.. _dac-sample:

Digital-to-Analog Converter (DAC)
#################################

Overview
********

This sample demonstrates how to use the DAC driver API.

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

The DAC output is defined in the board's devicetree and pinmux file.

The board's :ref:`/zephyr,user <dt-zephyr-user>` node must have ``dac``,
``dac-channel-id``, and ``dac-resolution`` properties set. See the predefined
overlays in :zephyr_file:`samples/drivers/dac/boards` for examples.

Building and Running for ST Nucleo L073RZ
=========================================
The sample can be built and executed for the
:ref:`nucleo_l073rz_board` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: nucleo_l073rz
   :goals: build flash
   :compact:

Building and Running for ST Nucleo L152RE
=========================================
The sample can be built and executed for the
:ref:`nucleo_l152re_board` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: nucleo_l152re
   :goals: build flash
   :compact:

Building and Running for ST Nucleo F767ZI
=========================================
The sample can be built and executed for the
:ref:`nucleo_f767zi_board` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: nucleo_f767zi
   :goals: build flash
   :compact:

Building and Running for ST Nucleo F429ZI
=========================================
The sample can be built and executed for the
:ref:`nucleo_f429zi_board` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: nucleo_f429zi
   :goals: build flash
   :compact:

Building and Running for NXP TWR-KE18F
======================================
The sample can be built and executed for the :ref:`twr_ke18f` as
follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: twr_ke18f
   :goals: build flash
   :compact:

DAC output is available on pin A32 of the primary TWR elevator
connector.

Building and Running for NXP FRDM-K64F
======================================
The sample can be built and executed for the :ref:`frdm_k64f` as
follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: frdm_k64f
   :goals: build flash
   :compact:

DAC output is available on connector J4 pin 11.

Building and Running for BL652
======================================
The BL652 DVK PCB contains a footprint for a MCP4725 to use as an external
DAC. Note this is not populated by default. The sample can be built and
executed for the :ref:`bl652_dvk` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: bl652_dvk
   :goals: build flash
   :compact:

DAC output is available on pin 1 of the MCP4725.

Building and Running for BL653
======================================
The BL653 DVK PCB contains a footprint for a MCP4725 to use as an external
DAC. Note this is not populated by default. The sample can be built and
executed for the :ref:`bl653_dvk` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: bl653_dvk
   :goals: build flash
   :compact:

DAC output is available on pin 1 of the MCP4725.

Building and Running for BL654
======================================
The BL654 DVK PCB contains a footprint for a MCP4725 to use as an external
DAC. Note this is not populated by default. The sample can be built and
executed for the :ref:`bl654_dvk` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/drivers/dac
   :board: bl654_dvk
   :goals: build flash
   :compact:

DAC output is available on pin 1 of the MCP4725.

Sample output
=============

You should see a sawtooth signal with an amplitude of the DAC reference
voltage and a period of approx. 4 seconds at the DAC output pin specified
by the board.

The following output is printed:

.. code-block:: console

   Generating sawtooth signal at DAC channel 1.

.. note:: If the DAC is not supported, the output will be an error message.