ESP8266 + 4x TM1637 == possible?

Question

I'm having trouble getting my NodeMCU connected to 4 x 4 Digit 7 Segment Displays.

So far I've been able to connect 2 & get them to display things from the demo repository.

However, after trying all possible combinations of different pins & looking up the pinout reference I have no idea why I can't get them to work.

Any help would be greatly appreciated.

I'm working with:

• ESP8266 NodeMCU ESP-12E (CP2102)

• 4 Digit 7 Segment Display (TM1637)

As suggested @romkey:

#include <Arduino.h>
#include <TM1637Display.h>

// Module connection pins (Digital Pins)

#define CLK_1 D2
#define DIO_1 D3

#define CLK_2 D5
#define DIO_2 D6

#define CLK_3 13
#define DIO_3 15

// The amount of time (in milliseconds) between tests
#define TEST_DELAY   500

TM1637Display display1(CLK_1, DIO_1);
TM1637Display display2(CLK_2, DIO_2);
TM1637Display display3(CLK_3, DIO_3);

void setup()
{
}

void loop()
{
  int k;
  uint8_t data[] = { 0xff, 0xff, 0xff, 0xff };
  uint8_t blank[] = { 0x00, 0x00, 0x00, 0x00 };
  display1.setBrightness(0x0f);
  display2.setBrightness(0x0f);
  display3.setBrightness(0x0f);
 
  // Brightness Test
  for(k = 0; k < 4; k++)
    data[k] = 0xff;
  for(k = 0; k < 7; k++) {
    display1.setBrightness(k);
    display1.setSegments(data);
    display2.setBrightness(k);
    display2.setSegments(data);
    display3.setBrightness(k);
    display3.setSegments(data);
    delay(TEST_DELAY);
  }
  while(1);
}

I've tried addressing the CLK_3 & DIO_3 pins as "Dx" but that didn't work as well.

Repos used:

• https://github.com/avishorp/TM1637