TM1637 4-digit display with ESP32-C3 SuperMini

The TM1637 module is the cheapest clock-style display: four 7-segment digits with a colon, driven over two wires. It suits a SuperMini kitchen timer or an NTP clock.

Wire CLK to GPIO6 and DIO to GPIO7 and power it from 3V3. The sketch shows uptime as MM:SS and blinks the colon every second — swap in NTP time once Wi-Fi is set up.

Wiring

Every connection
ESP32-C3 SuperMini	TM1637 4-digit 7-segment display	Wire	Notes
3V3	VCC	red	Bright enough indoors; the module’s pull-ups then sit at 3.3 V.
GND	GND	black
6	CLK	yellow
7	DIO	blue

3.3–5 V part, 3.3 V board. Works from 3.3 V or 5 V — power it from your board’s logic voltage so CLK/DIO stay in range. At 3.3 V the digits are a little dimmer.

Board quirks

CLK/DIO are not I2C even though they look like it — any two GPIOs work. GPIO6/7 avoid the strapping pins (2/8/9) and the UART pins (20/21).
Powered from 3V3 the module’s pull-ups go to 3.3 V, so nothing above 3.3 V reaches the C3. If you power it from 5V for more brightness, the pull-ups put 5 V on CLK/DIO — then add a level shifter.
Brightness 4 of 7 is plenty indoors and keeps the current (up to ~80 mA at full) off the SuperMini’s small regulator.

Code

tm1637-esp32c3.inoArduino C++Open in Playground Flash

// TM1637 4-digit 7-segment display on an ESP32-C3 SuperMini — shows uptime as MM:SS.
// VCC → 3V3, GND → GND, CLK → GPIO6, DIO → GPIO7.
// At 3V3 the module's pull-ups go to 3.3 V, so no level shifting is needed.
#include <TM1637Display.h>

constexpr uint8_t CLK_PIN = 6;
constexpr uint8_t DIO_PIN = 7;
TM1637Display display(CLK_PIN, DIO_PIN);

void setup() {
  Serial.begin(115200);
  delay(1500);  // let the native USB serial port enumerate
  display.setBrightness(4);  // 0–7
  display.clear();
  Serial.println("TM1637: CLK GPIO6, DIO GPIO7 — showing uptime MM:SS");
}

void loop() {
  uint32_t s = millis() / 1000;
  int mmss = (s / 60 % 100) * 100 + s % 60;
  bool colon = s % 2 == 0;  // blink the colon once a second
  display.showNumberDecEx(mmss, colon ? 0b01000000 : 0, true);
  static uint32_t last = 0;
  if (s != last) {
    last = s;
    Serial.printf("%02d:%02d\n", mmss / 100, mmss % 100);
  }
  delay(100);
}

// TM1637 4-digit 7-segment display on an ESP32-C3 SuperMini — shows uptime as MM:SS.
// VCC → 3V3, GND → GND, CLK → GPIO6, DIO → GPIO7.
// At 3V3 the module's pull-ups go to 3.3 V, so no level shifting is needed.
#include <TM1637Display.h>

constexpr uint8_t CLK_PIN = 6;
constexpr uint8_t DIO_PIN = 7;
TM1637Display display(CLK_PIN, DIO_PIN);

void setup() {
  Serial.begin(115200);
  delay(1500);  // let the native USB serial port enumerate
  display.setBrightness(4);  // 0–7
  display.clear();
  Serial.println("TM1637: CLK GPIO6, DIO GPIO7 — showing uptime MM:SS");
}

void loop() {
  uint32_t s = millis() / 1000;
  int mmss = (s / 60 % 100) * 100 + s % 60;
  bool colon = s % 2 == 0;  // blink the colon once a second
  display.showNumberDecEx(mmss, colon ? 0b01000000 : 0, true);
  static uint32_t last = 0;
  if (s != last) {
    last = s;
    Serial.printf("%02d:%02d\n", mmss / 100, mmss % 100);
  }
  delay(100);
}

Library: TM1637 (Avishay Orpaz) — compiled with TM1637 1.2.0.

Expected serial output

Serial Monitor · 115200Output

TM1637: CLK GPIO6, DIO GPIO7 — showing uptime MM:SS
00:01
00:02
00:03

TM1637: CLK GPIO6, DIO GPIO7 — showing uptime MM:SS
00:01
00:02
00:03

Common errors

Display stays blank

CLK and DIO swapped, or VCC/GND reversed on the 4-pin header. Swap the two signal pins in the code first.

Random segments flicker

Long jumper wires. Keep them under 20 cm.