Arduino project · Displays and counters · Easy
Digit Counter with Memory
Each press adds one to a digit display (0 to 9, then back to 0). After a power cut the same digit comes back.
What you will learn
- How to keep a display value across a power cut
- How a counter wraps around from 9 to 0
- How to use EEPROM with a 7-segment digit
How it works
The number is loaded at the start of each turn, shown, increased on a press and saved. Reset the simulator and the digit stays. 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
- Add a second button that counts down.
- Add a clear button.
- Use the memory for a lap counter.
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 counter board
The big sign shows the same number as your 7-segment display. Press the buttons in the simulator and watch it count.
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.
- 7-segment display = the big counter sign