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/*
* Author: Michael Ring <mail@michael-ring.org>
* Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
* Contributors: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
* Copyright (c) 2014 Intel Corporation.
*
* 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.
*
* Example usage: Display set of patterns on MAX7219 repeately.
* Press Ctrl+C to exit
*/
/* standard headers */
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
/* mraa header */
#include "mraa/spi.h"
/* SPI declaration */
#define SPI_BUS 0
/* SPI frequency in Hz */
#define SPI_FREQ 400000
uint16_t pat[] = { 0x01aa, 0x0255, 0x03aa, 0x0455, 0x05aa, 0x0655, 0x07aa, 0x0855 };
uint16_t pat_inv[] = { 0x0155, 0x02aa, 0x0355, 0x04aa, 0x0555, 0x06aa, 0x0755, 0x08aa };
uint16_t pat_clear[] = { 0x0100, 0x0200, 0x0300, 0x0400, 0x0500, 0x0600, 0x0700, 0x0800 };
volatile sig_atomic_t flag = 1;
void
sig_handler(int signum)
{
if (signum == SIGINT) {
fprintf(stdout, "Exiting...\n");
flag = 0;
}
}
int
main(int argc, char** argv)
{
mraa_result_t status = MRAA_SUCCESS;
mraa_spi_context spi;
int i, j;
/* initialize mraa for the platform (not needed most of the times) */
mraa_init();
//! [Interesting]
/* initialize SPI bus */
spi = mraa_spi_init(SPI_BUS);
if (spi == NULL) {
fprintf(stderr, "Failed to initialize SPI\n");
mraa_deinit();
return EXIT_FAILURE;
}
/* set SPI frequency */
status = mraa_spi_frequency(spi, SPI_FREQ);
if (status != MRAA_SUCCESS)
goto err_exit;
/* set big endian mode */
status = mraa_spi_lsbmode(spi, 0);
if (status != MRAA_SUCCESS) {
goto err_exit;
}
/* MAX7219/21 chip needs the data in word size */
status = mraa_spi_bit_per_word(spi, 16);
if (status != MRAA_SUCCESS) {
fprintf(stdout, "Failed to set SPI Device to 16Bit mode\n");
goto err_exit;
}
/* do not decode bits */
mraa_spi_write_word(spi, 0x0900);
/* brightness of LEDs */
mraa_spi_write_word(spi, 0x0a05);
/* show all scan lines */
mraa_spi_write_word(spi, 0x0b07);
/* set display on */
mraa_spi_write_word(spi, 0x0c01);
/* testmode off */
mraa_spi_write_word(spi, 0x0f00);
while (flag) {
/* set display pattern */
mraa_spi_write_buf_word(spi, pat, 16);
sleep(2);
/* set inverted display pattern */
mraa_spi_write_buf_word(spi, pat_inv, 16);
sleep(2);
/* clear the LED's */
mraa_spi_write_buf_word(spi, pat_clear, 16);
/* cycle through all LED's */
for (i = 1; i <= 8; i++) {
for (j = 0; j < 8; j++) {
mraa_spi_write_word(spi, (i << 8) + (1 << j));
sleep(1);
}
mraa_spi_write_word(spi, i << 8);
}
}
/* stop spi */
mraa_spi_stop(spi);
//! [Interesting]
/* deinitialize mraa for the platform (not needed most of the times) */
mraa_deinit();
return EXIT_SUCCESS;
err_exit:
mraa_result_print(status);
/* stop spi */
mraa_spi_stop(spi);
/* deinitialize mraa for the platform (not needed most of the times) */
mraa_deinit();
return EXIT_FAILURE;
}
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