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avr_demo/til311/firmware/main.c

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2.2 KiB
C

/*
* Loops through 0-F and displays it on TIL311. Pure C version.
*
* TIL311 pin 3 -> Arduino Digital 2 (PORTD2)
* TIL311 pin 2 -> Arduino Digital 3 (PORTD3)
* TIL311 pin 13 -> Arduino Digital 4 (PORTD4)
* TIL311 pin 12 -> Arduino Digital 5 (PORTD5)
*
* Led at Arduino Digital 13 (PORTB5)
*
* To compile and upload run: make clean; make; make flash;
*
* Copyright 2009 Mika Tuupola
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/mit-license.php
*
*/
#include <avr/io.h>
#include <util/delay.h>
#define BIT_AT(value, bit) (value & (1 << bit))
int main(void) {
/* Make PORTB5 (Arduino 13) and PORTD0-PORTD3 (Arduino 2-5) as an output. */
DDRB |= _BV(PORTB5);
DDRD |= _BV(PORTD2) | _BV(PORTD3) | _BV(PORTD4) | _BV(PORTD5);
for(;;) {
/* Reset displayed value. */
int value = 0;
while (value < 16) {
/* Toggle led at PORTB5 */
PORTB ^= _BV(PORTB5);
/* Short way would be to directly write the value to PORTD. */
/* Shift by 2 because first TIL311 port is PORTD2. However */
/* This would zero PORTD0, PORTD1, PORTD6 and PORTD7. */
/* PORTD = value << 2; */
/* TIL311 pin 3, latch data input A (1). */
if (0 == BIT_AT(value, 0)) {
PORTD &= ~(_BV(PORTD2));
} else {
PORTD |= _BV(PORTD2);
}
/* TIL311 pin 2, latch data input B (2). */
if (0 == BIT_AT(value, 1)) {
PORTD &= ~(_BV(PORTD3));
} else {
PORTD |= _BV(PORTD3);
}
/* TIL311 pin 13, latch data input C (4). */
if (0 == BIT_AT(value, 2)) {
PORTD &= ~(_BV(PORTD4));
} else {
PORTD |= _BV(PORTD4);
}
/* TIL311 pin 12, latch data input D (8). */
if (0 == BIT_AT(value, 3)) {
PORTD &= ~(_BV(PORTD5));
} else {
PORTD |= _BV(PORTD5);
}
value++;
_delay_ms(500);
}
}
/* This is never reached. */
return 0;
}