Arduino sketch for testing TIL311 / DIS1417 displays

til311-tester.ino

/*
 * TIL311 / DIS1417 tester
 * 
 * MSB_PIN -> input D
 *            input C
 *            input B
 * LSB_PIN -> input A
 * 
 * also hook up LATCH_PIN and BLANKING_PIN accordingly
 * 
 * 2016.09.14 darell tan
 */

// PWM pin. try to avoid 5 & 6
#define BLANKING_PIN    3

// LSB_PIN (larger) to MSB_PIN (smaller)
#define LATCH_PIN      13
#define LSB_PIN        12
#define MSB_PIN         9

void setup() {
  for (int i = LSB_PIN; i >= MSB_PIN; i--)
    pinMode(i, OUTPUT);

  pinMode(BLANKING_PIN, OUTPUT);
  analogWrite(BLANKING_PIN, 0);

  pinMode(LATCH_PIN, OUTPUT);
  digitalWrite(LATCH_PIN, 1);
}

static void send(unsigned int data) {
  data &= 0xF;

  for (int i = LSB_PIN; i >= MSB_PIN; i--) {
    digitalWrite(i, data & 1);
    data >>= 1;
  }

  // strobe it
  digitalWrite(LATCH_PIN, 0);

  delayMicroseconds(1); // T-setup = 40ns
  digitalWrite(LATCH_PIN, 1);
}

unsigned int count = 0;

int cycleCount = 0;
int dutyCycle = 0;

void loop() {
  // adjust brightness when it hits 0
  if (count == 0 && ++cycleCount == 1) {
    cycleCount = 0;

    analogWrite(BLANKING_PIN, dutyCycle);

    dutyCycle += 50;
    if (dutyCycle > 255)
      dutyCycle = 0;
  }

  send(count);
  count++;
  count &= 0xF;

  delay(500);
}