oled_array.ino

#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "Wire.h"
extern "C" {
#include "utility/twi.h"  // from Wire library, so we can do bus scanning
}

#define TCAADDR 0x70

void tcaselect(uint8_t i) {
  if (i > 7) return;

  Wire.beginTransmission(TCAADDR);
  Wire.write(1 << i);
  Wire.endTransmission();
}

Adafruit_SSD1306 displays[] = {
  Adafruit_SSD1306(-1),
  Adafruit_SSD1306(-1),
  Adafruit_SSD1306(-1),
  Adafruit_SSD1306(-1)
};

int pinsSelection[] = {0, 5, 7, 6};
int initPadding = 1;

void displayNumber(Adafruit_SSD1306* disp, int index) {
  disp->clearDisplay();
  disp->setTextSize(1);
  disp->setTextColor(WHITE);
  disp->setCursor(0, 0);
  disp->println(String(index));
  disp->display();
}

void setup() {

  Wire.begin();
  Serial.begin(9600);

  for (int i = 0; i < 4; i++) {
    tcaselect(pinsSelection[i]);
    displays[i].begin(SSD1306_SWITCHCAPVCC, 0x3C, false);
    displayNumber(&displays[i], i + 1);
  }

  initPadding += 1;
}

void loop() {
  for (int i = 0; i < 4; i++) {
    tcaselect(pinsSelection[i]);
    displayNumber(&displays[i], i + initPadding);
  }
  initPadding += 1;
  delay(5);
}