Fareed Mohmed← All projects

Arduino project · Displays and counters · Easy

Countdown Ring Timer

Press the button and the ring counts down eight seconds, one pixel at a time.

What you will learn

  • How to make a visual timer
  • How a ring shows the time left
  • How to end a timer with a sound

How it works

After the button press the ring starts full and loses one pixel every second. At zero the buzzer sounds.

Try this next

  • Make the timer 16 seconds with two seconds per pixel.
  • Use a knob to set the time.
  • Change the colour as time runs out.

The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.

1Choose your Arduino board
2Build the circuit
Parts: sensors and actuators (tap to show or hide)

Try the inputs (virtual sensors)

Pins (you can change them)

PartArduino 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.

#ColourFrom (part and leg)To
3Define the sequence

Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.

4Arduino code

5Parts list and where to buy

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.

#ItemQtySearch termBuy / compare
6Export

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.

7Learn: do’s, don’ts, cautions and tips

In the real world

A glowing ring of lights

The ring lights as many pixels as your program asks for, from green to red.

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.