Arduino project · Buttons and switches · Medium
433 MHz Transmitter with Two Buttons
Two buttons send key A and key B by radio. The green LED shows that a key was pressed.
What you will learn
- How to make your own remote control
- How a transmitter sends a number
- How key fobs work inside
How it works
Pressing Button1 sends 1 and Button2 sends 2. The Link monitor under the circuit shows each transmission.
Try this next
- Add keys C and D.
- Use a coin cell to make it portable.
- Build the receiver on a second Arduino.
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 radio key fob
Press a button on the fob. A radio message goes to the receiver, whose lamp lights.
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.
- Two buttons = the fob buttons
- Green LED = message sent