Arduino project · Displays and counters · Easy
Countdown 9 to 0 with Beeper
Press the button to start a 9 second countdown. At zero the buzzer sounds.
What you will learn
- How "wait until" starts a sequence on a button press
- How a countdown is a list of steps with 1 second gaps
- How to finish a sequence with an alarm
How it works
The program waits until the button is pressed. Then it shows 9, waits one second, shows 8, and so on down to 0. At 0 the buzzer beeps for 1.5 seconds and the program goes back to wait for the next press.
Try this next
- Change the gap to 500 ms for a faster countdown.
- Add a red LED that lights during the countdown.
- Beep a short tick every second.
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 countdown clock
The clock counts down and the buzzer beeps at the end, like a kitchen or rocket timer.
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 countdown
- Buzzer = the final beep