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Writer's pictureRamesh G

UP/DOWN counter using 7segment Display

In this tutorial, you will learn how you can test TM1637 4-digit 7-segment display and Counter function with adjusting time delay.

Components required

Arduino Nano - 1 no

TM1637 module - 1 no

Push Button switch - 2 no

5V/3.3V Power module - 1 no


Circuit diagram


TM1637

TM1637 seven segment modules is a ready made multiplexed seven segment display with 4 digits. The driver IC is TM1637; It has 4pin control there are GND, VCC, DIO, CLK. only two signal lines can make MCU control four Digit 7-segments LED can be used to display decimal, letters and so on. The 7segment LED Display has common anode type.


TM1637 4-Digit 7-Segment Display Specifications

Operating voltage 3.3 – 5 V

Current draw-80 mA

Operating temperature-10 – 80 °C


Interfacing TM1637 with the arduino:

So the first thing you want to do is connect the clock pin to any pin on the Arduino.

  • CLK clock pin of the TM1637 with the digital pin 3 of the arduno.

  • DIO pin of the TM1637 with digital pin 2 of the arduino.

  • VCC of the TM1637 with the 5V of the arduino.

  • Gnd of the TM1637 with the ground of the arduino.


Counter

In this example we use the TM1637 display module to make a simple counter with two push buttons. The setup is as shown below where the buttons are connected to pin 8 and 9 of Arduino nano.

This example shows the commonest basic functions of the TM1637Display.h library which are; setBrightness(): for setting the brightness of the display. There are seven levels of brightness therefore the value can be in 0x0a to 0x0f.


showNumberDec(): this is the most used function and it is for displaying decimal number digits. This function can take four arguments that is, showNumberDec (int num, bool leading_zero, uint8_t length, uint8_t pos), the first argument is the number to be displayed, the second is determining leading zeros and can either be true or false, the third argument is the number of digits to be displayed and the last argument is for selecting the position where the number to be displayed should begin from.

For example display.showNumberDec(25,false,2,1) displays the number 25 without leading zeros on the second and third digit


Installing Library

7segment: you need to Download and install the TM1637 library.


Follow the next steps to install those libraries.

In your Arduino IDE, to install the libraries go to Sketch > Include Library > Add .ZIP library… and select the library you’ve just downloaded.


After installing the required libraries, copy the following code to your Arduino IDE.


Arduino Code

First testing the TM1637 display check.

#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 500


const uint8_t SEG_DONE[] = {

SEG_B | SEG_C | SEG_D | SEG_E | SEG_G, // d

SEG_D | SEG_C | SEG_F | SEG_E | SEG_G, // b

SEG_C | SEG_D | SEG_E | SEG_G, // O

SEG_D | SEG_E | SEG_F | SEG_G, // t

};


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);

}




Next UP/DOWN Counter code


#include <TM1637Display.h>


#define UP 8

#define DOWN 9

const int CLK = 2; //Set the CLK pin connection to the display

const int DIO = 3; //Set the DIO pin connection to the display


const uint8_t blank[] = {0x00, 0x00, 0x00,0x00};


TM1637Display display(CLK, DIO); //set up the 4-Digit Display.


int num = 0;


// The amount of time (in milliseconds) between counter

#define COUNTER_DELAY 1000


void setup()

{

pinMode(UP, INPUT_PULLUP);

pinMode(DOWN,

INPUT_PULLUP);

display.setBrightness(0x0f); //set the diplay to brightness

display.setSegments(blank);//clear display

}


void loop()

{

display.showNumberDec(num, true, 4, 0);

delay(COUNTER_DELAY);

if( digitalRead(UP) )

{ // if the UP button is presses

num++; // increment 'num'

if(num > 9999)

num = 0;

}

if( digitalRead(DOWN) )

{ // if the DOWN button is presses

num--; // decrement 'num'

if(num < 0)

num = 9999;

}

}



Demo



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