Arduino project · LEDs and lights · Medium
Lucky Draw: One of Four LEDs
Press the button and a random LED lights up to pick the winner.
What you will learn
- How one random number chooses between many outputs
- How to compare a variable with several values
- How games pick a random player
How it works
"pick" becomes 0, 1, 2 or 3 at random. Four "If variable" steps each light one LED when the number matches and turn it off otherwise.
Try this next
- Add a fanfare buzzer.
- Use a servo pointer instead of LEDs.
- Add a button to choose how many players.
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 game of chance
Press the button. The bulbs light up at random, like a game show wheel.
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.
- Button = your try
- LEDs = the result