The TM-1637 is a 7-segment 4-digit display that can be easily controlled with a few wires on an Arduino. The display is controlled by a TM1637 integrated circuit which does everything related to lighting up the correct segments that build up each of the digits when input from the microcontroller board arrives. 

The TM1637 supports ON/OFF and brightness control of the LEDs as well as accessing each of the segments. It also allows you to adjust the brightness of the LEDs at the software level. And once the display is updated by the microcontroller, the TM1637 then takes care of all the work of refreshing the display. Which can leave the microcontroller to do the essential things.

 

Specifications::

• Display common anode for the four red LED
• Powered supply by 3.3V/5V
• Four common anode tube display module is driven by IC TM1637
• Can be used with Arduino Boards, using two signal lines can make the MCU control 4 8 digital. 
• Working current: 30 / 80 mA.
• Size: 42 x 24 x 11 mm / 1.65 x 0.94 x 0.43 inches.

 

Pinout of the TM1637 LED Display Module :

Pin Name	Description
CLK	clock input pin. Connect to any digital pin on Arduino.
DIO	Data I/O pin. Connect to any digital pin on Arduino.
VCC	supplies power to the module. Connect it to the 3.3V to 5V power supply.
GND	ground pin.

 

Arduino Library for the 7 segments TM1637 4-bit Common Anode LED Display Module :

The library can be downloaded from https://github.com/avishorp/TM1637. you need to add it to the Arduino IDE

 

Connections:

• CLK  to Pin 2
• DIO  to Pin 3
• VCC to 5v
• GND TO GND

 

Code:

#include "Arduino.h"
#include "TM1637Display.h"

// Module connection pins (Digital Pins)
#define CLK 2
#define DIO 3

// The amount of time (in milliseconds) between tests
#define TEST_DELAY   2000

const uint8_t SEG_DONE[] = {
	SEG_B | SEG_C | SEG_D | SEG_E | SEG_G,           // d
	SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F,   // O
	SEG_C | SEG_E | SEG_G,                           // n
	SEG_A | SEG_D | SEG_E | SEG_F | SEG_G            // E
	};

TM1637Display display(CLK, DIO);

void setup()
{
}

void loop()
{
  int k;
  uint8_t data[] = { 0xff, 0xff, 0xff, 0xff };
  uint8_t blank[] = { 0x00, 0x00, 0x00, 0x00 };
  display.setBrightness(0x0f);

  // All segments on
  display.setSegments(data);
  delay(TEST_DELAY);

  // Selectively set different digits
  data[0] = display.encodeDigit(0);
  data[1] = display.encodeDigit(1);
  data[2] = display.encodeDigit(2);
  data[3] = display.encodeDigit(3);
  display.setSegments(data);
  delay(TEST_DELAY);

  /*
  for(k = 3; k >= 0; k--) {
	display.setSegments(data, 1, k);
	delay(TEST_DELAY);
	}
  */

  display.clear();
  display.setSegments(data+2, 2, 2);
  delay(TEST_DELAY);

  display.clear();
  display.setSegments(data+2, 2, 1);
  delay(TEST_DELAY);

  display.clear();
  display.setSegments(data+1, 3, 1);
  delay(TEST_DELAY);


  // Show decimal numbers with/without leading zeros
  display.showNumberDec(0, false); // Expect: ___0
  delay(TEST_DELAY);
  display.showNumberDec(0, true);  // Expect: 0000
  delay(TEST_DELAY);
	display.showNumberDec(1, false); // Expect: ___1
	delay(TEST_DELAY);
  display.showNumberDec(1, true);  // Expect: 0001
  delay(TEST_DELAY);
  display.showNumberDec(301, false); // Expect: _301
  delay(TEST_DELAY);
  display.showNumberDec(301, true); // Expect: 0301
  delay(TEST_DELAY);
  display.clear();
  display.showNumberDec(14, false, 2, 1); // Expect: _14_
  delay(TEST_DELAY);
  display.clear();
  display.showNumberDec(4, true, 2, 2);  // Expect: __04
  delay(TEST_DELAY);
  display.showNumberDec(-1, false);  // Expect: __-1
  delay(TEST_DELAY);
  display.showNumberDec(-12);        // Expect: _-12
  delay(TEST_DELAY);
  display.showNumberDec(-999);       // Expect: -999
  delay(TEST_DELAY);
  display.clear();
  display.showNumberDec(-5, false, 3, 0); // Expect: _-5_
  delay(TEST_DELAY);
  display.showNumberHexEx(0xf1af);        // Expect: f1Af
  delay(TEST_DELAY);
  display.showNumberHexEx(0x2c);          // Expect: __2C
  delay(TEST_DELAY);
  display.showNumberHexEx(0xd1, 0, true); // Expect: 00d1
  delay(TEST_DELAY);
  display.clear();
  display.showNumberHexEx(0xd1, 0, true, 2); // Expect: d1__
  delay(TEST_DELAY);
  
	// Run through all the dots
	for(k=0; k <= 4; k++) {
		display.showNumberDecEx(0, (0x80 >> k), true);
		delay(TEST_DELAY);
	}

  // Brightness Test
  for(k = 0; k < 4; k++)
	data[k] = 0xff;
  for(k = 0; k < 7; k++) {
    display.setBrightness(k);
    display.setSegments(data);
    delay(TEST_DELAY);
  }
  
  // On/Off test
  for(k = 0; k < 4; k++) {
    display.setBrightness(7, false);  // Turn off
    display.setSegments(data);
    delay(TEST_DELAY);
    display.setBrightness(7, true); // Turn on
    display.setSegments(data);
    delay(TEST_DELAY);  
  }

 
  // Done!
  display.setSegments(SEG_DONE);

  while(1);
}