Arduino Mega - TM1637 4-Digit 7-Segment Display
Got an Arduino Mega and want to add a numeric display to your project? The TM1637 4-digit 7-segment display module needs only two wires for data and works with any digital pin on the Mega. With the DIYables_4Digit7Segment_TM1637 library you can start writing code in minutes.
This step-by-step walkthrough covers:
- Wiring the TM1637 module to the Arduino Mega.
- Displaying integers, text strings, and temperature.
- Showing time in HH:MM format with a blinking colon.
- Controlling individual digits, characters, and brightness.
The Mega brings extra I/O, more SRAM, and additional hardware serial ports - handy when your project needs to talk to sensors or other peripherals alongside the display.
Hardware Preparation
Or you can buy the following kits:
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables .
Additionally, some of these links are for products from our own brand, DIYables .
Understanding the TM1637 Display Module
The TM1637 is a dedicated LED driver that takes care of multiplexing four 7-segment digits. It communicates over a 2-wire protocol (CLK and DIO) and stores digit data in its own internal memory. That means the display keeps showing whatever you wrote to it, even if your code moves on to do other things.
What you get with this module:
- 4 digits, each with 7 segments and a decimal point
- A colon separator between the second and third digit
- 8 brightness settings
- 2-wire interface, compatible with 3.3V and 5V
- No refresh loop required
| Function | Pin |
|---|---|
| CLK | Clock signal |
| DIO | Data I/O |
| VCC | 3.3V or 5V |
| GND | Ground |
You can hook CLK and DIO to any digital pin on the Mega. The examples use pins 2 and 3.
Wiring Diagram
Wire up the TM1637 module:
- CLK to Mega pin 9
- DIO to Mega pin 10
- VCC to 5V
- GND to GND
This image is created using Fritzing. Click to enlarge image
Installing the Library
- Connect your Arduino Mega to the computer via a USB cable.
- Open the Arduino IDE. Pick Arduino Mega or Mega 2560 as the board and choose the correct port.
- Go to the Libraries panel on the left side.
- Search for "DIYables_4Digit7Segment_TM1637". Find the entry from DIYables.
- Press Install.
The library has zero external dependencies.
Code Skeleton
The bare minimum to get started:
#include <DIYables_4Digit7Segment_TM1637.h>
#define CLK_PIN 9
#define DIO_PIN 10
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
void setup() {
display.begin();
display.print(1234);
}
void loop() {
}
Create the display object, call begin(), and write to the display. That is all you need to see digits light up.
Example - Display Integer Numbers
Shows various integers on the display including negative numbers and zero-padded values.
/*
* This Arduino Mega code was developed by newbiely.com
*
* This Arduino Mega code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-mega/arduino-mega-tm1637-4-digit-7-segment-display
*/
/*
* DIYables_4Digit7Segment_TM1637 - Integer Example
*
* Displays various integer values on a 4-digit 7-segment display
* with TM1637 driver, including zero-padded numbers.
*
* Tutorial: https://diyables.io/products/4-digit-7-segment-display-led-tm1637-with-colon
*
* TESTED HARDWARE:
* - Arduino Uno R3
* - Arduino Uno R4 WiFi
* - Arduino Uno R4 Minima
* - Arduino Mega
* - Arduino Due
* - Arduino Giga
* - DIYables STEM V3: https://diyables.io/stem-v3
* - DIYables STEM V4 IoT: https://diyables.io/stem-v4-iot
* - DIYables STEM V4B IoT: https://diyables.io/stem-v4b-iot
* - DIYables STEM V4B Edu: https://diyables.io/stem-v4-edu
* - DIYables MEGA2560 R3: https://diyables.io/atmega2560-board
* - DIYables Nano R3: https://diyables.io/nano-board
* - DIYables ESP32 Board: https://diyables.io/esp32-board
* - DIYables ESP32 S3, Uno-form factor: https://diyables.io/esp32-s3-uno
* - It is expected to work with other boards
*/
#include <DIYables_4Digit7Segment_TM1637.h>
// Pin configuration - change to match your wiring
#define CLK_PIN 9 // The Arduino pin connected to the CLK pin of TM1637 4-digit 7-segment display
#define DIO_PIN 10 // The Arduino pin connected to the DIO pin of TM1637 4-digit 7-segment display
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
void setup() {
Serial.begin(9600);
display.begin();
Serial.println("TM1637 Integer Example");
}
void loop() {
// Display various integers
int numbers[] = {0, 42, 1234, -5, -123, 9999};
int count = sizeof(numbers) / sizeof(numbers[0]);
for (int i = 0; i < count; i++) {
display.print(numbers[i]);
Serial.print("Displaying: ");
Serial.println(numbers[i]);
delay(2000);
}
// Display with zero padding
display.print(42, true); // Shows "0042"
Serial.println("Displaying: 0042 (zero-padded)");
delay(2000);
}
Steps to Upload
- Connect the TM1637 module to the Mega as shown in the wiring diagram.
- Plug in the USB cable.
- Paste the code into Arduino IDE, select the board and port, and hit Upload.
- Open the Serial Monitor (9600 baud) to watch the output.
The display cycles through 0, 42, 1234, -5, -123, 9999, and then shows "0042" with zero-padding.
API at a Glance
| Method | Effect | Sample Call |
|---|---|---|
| print(int) | Shows an integer on the display | display.print(1234) |
| print(int, true) | Adds leading zeros | display.print(42, true) |
| clear() | Blanks all digits | display.clear() |
Example - Display Text and Temperature
Shows text strings and formatted temperature with the degree symbol.
/*
* This Arduino Mega code was developed by newbiely.com
*
* This Arduino Mega code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-mega/arduino-mega-tm1637-4-digit-7-segment-display
*/
/*
* DIYables_4Digit7Segment_TM1637 - TextAndDegree Example
*
* Displays text strings, special characters, and temperature
* on a 4-digit 7-segment display with TM1637 driver.
*
* Tutorial: https://diyables.io/products/4-digit-7-segment-display-led-tm1637-with-colon
*
* TESTED HARDWARE:
* - Arduino Uno R3
* - Arduino Uno R4 WiFi
* - Arduino Uno R4 Minima
* - Arduino Mega
* - Arduino Due
* - Arduino Giga
* - DIYables STEM V3: https://diyables.io/stem-v3
* - DIYables STEM V4 IoT: https://diyables.io/stem-v4-iot
* - DIYables STEM V4B IoT: https://diyables.io/stem-v4b-iot
* - DIYables STEM V4B Edu: https://diyables.io/stem-v4-edu
* - DIYables MEGA2560 R3: https://diyables.io/atmega2560-board
* - DIYables Nano R3: https://diyables.io/nano-board
* - DIYables ESP32 Board: https://diyables.io/esp32-board
* - DIYables ESP32 S3, Uno-form factor: https://diyables.io/esp32-s3-uno
* - It is expected to work with other boards
*/
#include <DIYables_4Digit7Segment_TM1637.h>
// Pin configuration - change to match your wiring
#define CLK_PIN 9 // The Arduino pin connected to the CLK pin of TM1637 4-digit 7-segment display
#define DIO_PIN 10 // The Arduino pin connected to the DIO pin of TM1637 4-digit 7-segment display
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
void setup() {
Serial.begin(9600);
display.begin();
Serial.println("TM1637 Text and Degree Example");
}
void loop() {
// Display text strings
const char* texts[] = {"HELP", "Hi", "COOL", "done"};
for (int i = 0; i < 4; i++) {
display.print(texts[i]);
Serial.print("Displaying: ");
Serial.println(texts[i]);
delay(2000);
}
// Display temperature with degree symbol
display.printTemperature(25, 'C'); // Shows "25°C"
Serial.println("Displaying: 25 degrees C");
delay(2000);
display.printTemperature(72, 'F'); // Shows "72°F"
Serial.println("Displaying: 72 degrees F");
delay(2000);
// Display string with degree constant
char buf[5];
buf[0] = '2';
buf[1] = '5';
buf[2] = DIYables_4Digit7Segment_TM1637::DEGREE;
buf[3] = 'C';
buf[4] = '\0';
display.print(buf); // Same as printTemperature(25, 'C')
Serial.println("Displaying: 25 degrees C (via print)");
delay(2000);
}
Steps to Upload
- Wire the module as described above.
- Upload and open the Serial Monitor.
The display shows "HELP", "Hi", "COOL", "done", then "25°C" and "72°F".
API at a Glance
| Method | Effect | Sample Call |
|---|---|---|
| print(const char*) | Shows text (up to 4 characters) | display.print("HELP") |
| printTemperature(int, char) | Shows temperature with degree/unit | display.printTemperature(25, 'C') |
| DEGREE | Degree symbol for strings | display.DEGREE |
Example - Display Time with Colon
Shows time in HH:MM format with the colon blinking every 500ms.
/*
* This Arduino Mega code was developed by newbiely.com
*
* This Arduino Mega code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-mega/arduino-mega-tm1637-4-digit-7-segment-display
*/
/*
* DIYables_4Digit7Segment_TM1637 - Time Example
*
* Displays time in HH:MM format with blinking colon separator
* on a 4-digit 7-segment display with TM1637 driver.
*
* Tutorial: https://diyables.io/products/4-digit-7-segment-display-led-tm1637-with-colon
*
* TESTED HARDWARE:
* - Arduino Uno R3
* - Arduino Uno R4 WiFi
* - Arduino Uno R4 Minima
* - Arduino Mega
* - Arduino Due
* - Arduino Giga
* - DIYables STEM V3: https://diyables.io/stem-v3
* - DIYables STEM V4 IoT: https://diyables.io/stem-v4-iot
* - DIYables STEM V4B IoT: https://diyables.io/stem-v4b-iot
* - DIYables STEM V4B Edu: https://diyables.io/stem-v4-edu
* - DIYables MEGA2560 R3: https://diyables.io/atmega2560-board
* - DIYables Nano R3: https://diyables.io/nano-board
* - DIYables ESP32 Board: https://diyables.io/esp32-board
* - DIYables ESP32 S3, Uno-form factor: https://diyables.io/esp32-s3-uno
* - It is expected to work with other boards
*/
#include <DIYables_4Digit7Segment_TM1637.h>
// Pin configuration - change to match your wiring
#define CLK_PIN 9 // The Arduino pin connected to the CLK pin of TM1637 4-digit 7-segment display
#define DIO_PIN 10 // The Arduino pin connected to the DIO pin of TM1637 4-digit 7-segment display
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
int hours = 12;
int minutes = 30;
bool colonOn = true;
void setup() {
Serial.begin(9600);
display.begin();
Serial.println("TM1637 Time Example");
Serial.println("Displaying 12:30 with blinking colon");
}
void loop() {
display.printTime(hours, minutes, colonOn);
delay(500); // Toggle colon every 500ms for blinking effect
colonOn = !colonOn;
}
Steps to Upload
- Wire the module and upload the sketch.
- The display shows "12:30" with a blinking colon.
API at a Glance
| Method | Effect | Sample Call | |
|---|---|---|---|
| printTime(int, int) | Displays HH | MM with colon | display.printTime(12, 30) |
| printTime(int, int, bool) | Controls colon on/off | display.printTime(12, 30, false) |
Example - Blink the Display
Uses off() and on() to blink the entire display while keeping its content.
/*
* This Arduino Mega code was developed by newbiely.com
*
* This Arduino Mega code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-mega/arduino-mega-tm1637-4-digit-7-segment-display
*/
/*
* DIYables_4Digit7Segment_TM1637 - Blink Example
*
* Blinks integer and text on a 4-digit 7-segment display
* using off() and on() to toggle the display.
*
* Tutorial: https://diyables.io/products/4-digit-7-segment-display-led-tm1637-with-colon
*
* TESTED HARDWARE:
* - Arduino Uno R3
* - Arduino Uno R4 WiFi
* - Arduino Uno R4 Minima
* - Arduino Mega
* - Arduino Due
* - Arduino Giga
* - DIYables STEM V3: https://diyables.io/stem-v3
* - DIYables STEM V4 IoT: https://diyables.io/stem-v4-iot
* - DIYables STEM V4B IoT: https://diyables.io/stem-v4b-iot
* - DIYables STEM V4B Edu: https://diyables.io/stem-v4-edu
* - DIYables MEGA2560 R3: https://diyables.io/atmega2560-board
* - DIYables Nano R3: https://diyables.io/nano-board
* - DIYables ESP32 Board: https://diyables.io/esp32-board
* - DIYables ESP32 S3, Uno-form factor: https://diyables.io/esp32-s3-uno
* - It is expected to work with other boards
*/
#include <DIYables_4Digit7Segment_TM1637.h>
// Pin configuration - change to match your wiring
#define CLK_PIN 9 // The Arduino pin connected to the CLK pin of TM1637 4-digit 7-segment display
#define DIO_PIN 10 // The Arduino pin connected to the DIO pin of TM1637 4-digit 7-segment display
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
void setup() {
Serial.begin(9600);
display.begin();
Serial.println("TM1637 Blink Example");
}
void loop() {
// Blink an integer
display.print(1234);
Serial.println("Blinking: 1234");
for (int i = 0; i < 5; i++) {
display.off();
delay(300);
display.on();
delay(300);
}
delay(1000);
// Blink text
display.print("HELP");
Serial.println("Blinking: HELP");
for (int i = 0; i < 5; i++) {
display.off();
delay(300);
display.on();
delay(300);
}
delay(1000);
}
Steps to Upload
- Upload the code. Watch "1234" blink five times, then "HELP" blinks five times.
API at a Glance
| Method | Effect | Sample Call |
|---|---|---|
| off() | Turns display off (data stays) | display.off() |
| on() | Turns display back on | display.on() |
| setBrightness(int) | Sets brightness 0-7 | display.setBrightness(4) |
Example - Individual Digit Control
Sets each digit independently with numbers, characters, and colon.
/*
* This Arduino Mega code was developed by newbiely.com
*
* This Arduino Mega code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-mega/arduino-mega-tm1637-4-digit-7-segment-display
*/
/*
* DIYables_4Digit7Segment_TM1637 - IndividualDigits Example
*
* Sets individual digits, characters, and colon on a 4-digit
* 7-segment display with TM1637 driver.
*
* Tutorial: https://diyables.io/products/4-digit-7-segment-display-led-tm1637-with-colon
*
* TESTED HARDWARE:
* - Arduino Uno R3
* - Arduino Uno R4 WiFi
* - Arduino Uno R4 Minima
* - Arduino Mega
* - Arduino Due
* - Arduino Giga
* - DIYables STEM V3: https://diyables.io/stem-v3
* - DIYables STEM V4 IoT: https://diyables.io/stem-v4-iot
* - DIYables STEM V4B IoT: https://diyables.io/stem-v4b-iot
* - DIYables STEM V4B Edu: https://diyables.io/stem-v4-edu
* - DIYables MEGA2560 R3: https://diyables.io/atmega2560-board
* - DIYables Nano R3: https://diyables.io/nano-board
* - DIYables ESP32 Board: https://diyables.io/esp32-board
* - DIYables ESP32 S3, Uno-form factor: https://diyables.io/esp32-s3-uno
* - It is expected to work with other boards
*/
#include <DIYables_4Digit7Segment_TM1637.h>
// Pin configuration - change to match your wiring
#define CLK_PIN 9 // The Arduino pin connected to the CLK pin of TM1637 4-digit 7-segment display
#define DIO_PIN 10 // The Arduino pin connected to the DIO pin of TM1637 4-digit 7-segment display
DIYables_4Digit7Segment_TM1637 display(CLK_PIN, DIO_PIN);
void setup() {
Serial.begin(9600);
display.begin();
Serial.println("TM1637 Individual Digits Example");
}
void loop() {
// Set individual numbers on each digit position
display.clear();
display.setNumber(0, 1);
display.setNumber(1, 2);
display.setNumber(2, 3);
display.setNumber(3, 4);
Serial.println("Displaying: 1234");
delay(2000);
// Turn colon on
display.setColon(true);
Serial.println("Displaying: 12:34");
delay(2000);
// Turn colon off
display.setColon(false);
Serial.println("Displaying: 1234");
delay(2000);
// Set individual characters
display.clear();
display.setChar(0, 'H');
display.setChar(1, 'E');
display.setChar(2, 'L');
display.setChar(3, 'P');
Serial.println("Displaying: HELP");
delay(2000);
// Mix characters and numbers with colon
display.clear();
display.setChar(0, 'A');
display.setNumber(1, 3);
display.setChar(2, 'b');
display.setNumber(3, 7);
display.setColon(true);
Serial.println("Displaying: A3:b7");
delay(2000);
// Blinking colon effect
display.clear();
display.setNumber(0, 1);
display.setNumber(1, 2);
display.setNumber(2, 3);
display.setNumber(3, 0);
Serial.println("Blinking colon: 12:30");
for (int i = 0; i < 5; i++) {
display.setColon(true);
delay(500);
display.setColon(false);
delay(500);
}
delay(1000);
}
Steps to Upload
- Upload and observe the different digit combinations.
API at a Glance
| Method | Effect | Sample Call |
|---|---|---|
| setNumber(int, int) | Sets a digit 0-9 at a position | display.setNumber(0, 1) |
| setChar(int, char) | Sets a character at a position | display.setChar(0, 'H') |
| setColon(bool) | Controls the colon | display.setColon(true) |
| setSegments(int, uint8_t) | Sets raw segment bits | display.setSegments(0, 0x76) |
Common Problems and Fixes
| Symptom | Likely Cause | Fix |
|---|---|---|
| Display is blank | Wrong wiring or pins | Verify CLK/DIO connections match code |
| Wrong characters appear | CLK and DIO swapped | Swap the two wires |
| Display too dim | Low brightness setting | Call setBrightness(7) |
| Compile error | Library missing | Install DIYables_4Digit7Segment_TM1637 from Library Manager |
Platform Support
Built entirely on Arduino standard APIs - compatible with every Arduino-supported architecture.