/*
Arduino code for Individual control over each pin
Support for 40+ 74HC595 8 bit shift registers
http://bildr.org/2011/02/74hc595/
*/
#define DATA_PIN 8 // Pin connected to DS of 74HC595
#define LATCH_PIN 9 // Pin connected to STCP of 74HC595
#define CLOCK_PIN 10 // Pin connected to SHCP of 74HC595
// How many of the shift registers
#define NUM_SHIFT_REGS 2
const uint8_t numOfRegisterPins = NUM_SHIFT_REGS * 8;
bool registers[numOfRegisterPins];
void setup() {
pinMode(DATA_PIN, OUTPUT);
pinMode(CLOCK_PIN, OUTPUT);
pinMode(LATCH_PIN, OUTPUT);
clearRegisters();
writeRegisters();
}
bool toggle = false;
void loop() {
for (uint8_t i = 0; i < 16; i++) {
if (i % 2 == 0) {
setRegisterPin(i, toggle);
} else {
setRegisterPin(i, !toggle);
}
writeRegisters();
}
toggle = !toggle;
delay(500);
}
void clearRegisters() {
// Reset all register pins
for (int i = numOfRegisterPins - 1; i >= 0; i--) {
registers[i] = LOW;
}
}
void setRegisterPin(int index, int value) {
// Set an individual pin HIGH or LOW
registers[index] = value;
}
void writeRegisters() {
// Set and display registers
digitalWrite(LATCH_PIN, LOW);
for (int i = numOfRegisterPins - 1; i >= 0; i--) {
digitalWrite(CLOCK_PIN, LOW);
digitalWrite(DATA_PIN, registers[i]);
digitalWrite(CLOCK_PIN, HIGH);
}
digitalWrite(LATCH_PIN, HIGH);
}