109 lines
3.2 KiB
C
109 lines
3.2 KiB
C
/*
|
|
* Code to write data to two daisychained TPIC6B595 SIPO shift registers.
|
|
*
|
|
* The TPIC6B595 is a monolithic, high-voltage, medium-current power 8-bit
|
|
* shift register designed for use in systems that require relatively high
|
|
* load power.
|
|
*
|
|
* This device contains an 8-bit serial-in, parallel-out shift register that
|
|
* feeds an 8-bit D-type storage register. Data transfers through both the
|
|
* shift and storage registers on the rising edge of the shift-register clock
|
|
* (SRCK) and the register clock (RCK), respectively. The storage register
|
|
* transfers data to the output buffer when shift-register clear (SRCLR) is
|
|
* high. When SRCLR is low, the input shift register is cleared. When output
|
|
* enable (G) is held high, all data in the output buffers is held low and all
|
|
* drain outputs are off. When G is held low, data from the storage register
|
|
* is transparent to the output buffers. When data in the output buffers is
|
|
* low, the DMOS-transistor outputs are off. When data is high, the DMOS-
|
|
* transistor outputs have sink-current capability. The serial output (SER
|
|
* OUT) allows for cascading of the data from the shift register to additional
|
|
* devices.
|
|
*
|
|
* http://www.adafruit.com/datasheets/tpic6b595.pdf
|
|
*
|
|
* To compile and upload run: make clean; make; make program;
|
|
*
|
|
* Copyright 2011 Mika Tuupola
|
|
*
|
|
* Licensed under the MIT license:
|
|
* http://www.opensource.org/licenses/mit-license.php
|
|
*
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <util/delay.h>
|
|
|
|
#include "main.h"
|
|
#include "uart/uart.h"
|
|
#include "pins/digital.h"
|
|
|
|
//#define LATCH 10 /* RCK */
|
|
//#define DATA 11 /* SER IN */
|
|
//#define CLOCK 13 /* SRCK */
|
|
|
|
#define LATCH B0 /* RCK */
|
|
#define DATA B2 /* SER IN */
|
|
#define CLOCK B1 /* SRCK */
|
|
|
|
|
|
static void init(void) {
|
|
pin_mode(LATCH, OUTPUT);
|
|
pin_mode(CLOCK, OUTPUT);
|
|
pin_mode(DATA, OUTPUT);
|
|
}
|
|
|
|
/* Assumes MSB first. */
|
|
void shift_out(uint8_t data) {
|
|
for(uint8_t i = 0; i < 8; i++) {
|
|
/* Write bit to data port. */
|
|
if (0 == (data & _BV(7 - i))) {
|
|
digital_write(DATA, LOW);
|
|
} else {
|
|
digital_write(DATA, HIGH);
|
|
}
|
|
|
|
/* Pulse clock input to write next bit. */
|
|
digital_write(CLOCK, LOW);
|
|
digital_write(CLOCK, HIGH);
|
|
}
|
|
}
|
|
|
|
int main(void) {
|
|
|
|
init();
|
|
uart_init();
|
|
stdout = &uart_output;
|
|
stdin = &uart_input;
|
|
char binary[17];
|
|
|
|
/* Show pattern for 5 seconds. */
|
|
shift_out(0b10101010);
|
|
shift_out(0b11110000);
|
|
digital_write(LATCH, LOW);
|
|
digital_write(LATCH, HIGH);
|
|
_delay_ms(5000);
|
|
|
|
while (1) {
|
|
for(uint16_t i = 0; i < 0xffff; i++) {
|
|
|
|
/* Print the number to serial for debugging. */
|
|
itoa(i, binary, 2);
|
|
printf("%s %d \n", binary, i);
|
|
|
|
/* Shift high byte first to shift register. */
|
|
shift_out(i >> 8);
|
|
shift_out(i & 0xff);
|
|
|
|
/* Pulse latch to transfer data from shift registers */
|
|
/* to storage registers (should this be inside shift_out()?). */
|
|
digital_write(LATCH, LOW);
|
|
digital_write(LATCH, HIGH);
|
|
|
|
_delay_ms(50);
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
}
|