Arduino project · Displays and counters · Medium
4-Digit Counter That Remembers (TM1637)
A 4-digit display counts from 0 to 9999. Button 1 adds one, button 2 clears it, and the number is kept in EEPROM through a power cut.
What you will learn
- How to drive a TM1637 four-digit display
- How a number up to 9999 fits in an int variable
- How to keep a counter through a power cut
How it works
The program loads the saved number, shows it, waits for a button, changes it and saves it again. Reset the simulator and the number returns. Real EEPROM survives about 100,000 writes, so a real program should save only when the number changes, as this one does.
Try this next
- Count with an IR sensor instead of a button.
- Count a production line and keep the total.
- Add a buzzer every 100 counts.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A 4-digit display board
The big board shows the same number as your 4-digit display.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- 4-digit display = the big board