Analog Write¶
About¶
Write analog values to an analog output pin to form a sawtooth wave. Connect a LED to the analog output pin and watch the brightness of the LED change.
Source code¶
/**
* @section License
*
* The MIT License (MIT)
*
* Copyright (c) 2014-2017, Erik Moqvist
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* This file is part of the Simba project.
*/
#include "simba.h"
int main()
{
int value;
struct analog_output_pin_t pin;
sys_start();
analog_output_pin_module_init();
/* Initialize the analog output pin. */
analog_output_pin_init(&pin, &pin_d10_dev);
value = 0;
while (1) {
/* Write a sawtooth wave to the analog output pin. */
analog_output_pin_write(&pin, value);
value += 5;
value %= 1024;
/* Wait ten milliseconds. */
thrd_sleep_ms(10);
}
return (0);
}
The source code can also be found on Github in the examples/analog_write folder.
Build and run¶
Build and upload the application.
$ cd examples/analog_write
$ make -s BOARD=<board> upload