int
main(int argc, char** argv)
{
//! [Interesting]
mraa_spi_context spi;
spi = mraa_spi_init(1);
if (spi == NULL) {
printf("Initialization of spi failed, check syslog for details, exit...\n");
exit(1);
}
printf("SPI initialised successfully\n");
mraa_spi_frequency(spi, 400000);
mraa_spi_lsbmode(spi, 0);
// The MAX7219/21 Chip needs the data in word size
if (mraa_spi_bit_per_word(spi, 16) != MRAA_SUCCESS) {
printf("Could not set SPI Device to 16Bit mode, exit...\n");
exit(1);
};
mraa_spi_write_word(spi, 0x0900); // Do not decode bits
mraa_spi_write_word(spi, 0x0a05); // Brightness of LEDs
mraa_spi_write_word(spi, 0x0b07); // Show all Scan Lines
mraa_spi_write_word(spi, 0x0c01); // Display on
mraa_spi_write_word(spi, 0x0f00); // Testmode off
// Display Pattern on the display
uint16_t dataAA55[] = { 0x01aa, 0x0255, 0x03aa, 0x0455, 0x05aa, 0x0655, 0x07aa, 0x0855 };
mraa_spi_write_buf_word(spi, dataAA55, 16);
sleep(2);
// Display inverted Pattern
uint16_t data55AA[] = { 0x0155, 0x02aa, 0x0355, 0x04aa, 0x0555, 0x06aa, 0x0755, 0x08aa };
mraa_spi_write_buf_word(spi, data55AA, 16);
sleep(2);
// Clear the display
uint16_t data[] = { 0x0100, 0x0200, 0x0300, 0x0400, 0x0500, 0x0600, 0x0700, 0x0800 };
mraa_spi_write_buf_word(spi, data, 16);
int i;
int j;
// 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);
}
mraa_spi_stop(spi);
//! [Interesting]
}
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;
}
/**
* Write buffer of bytes to SPI device The pointer return has to be
* free'd by the caller. It will return a NULL pointer in cases of
* error
*
* @param txBuf buffer to send
* @param length size of buffer (in bytes) to send
* @return uint8_t* data received on the miso line. Same length as passed in
*/
uint16_t*
write_word(uint16_t* txBuf, int length)
{
return mraa_spi_write_buf_word(m_spi, txBuf, length);
}
