How to Build a Simple Arduino Morse Code Transmitter From Scratch

Building a simple Arduino-based Morse code transmitter from scratch is a fun electronics project that can be completed in just a few hours. With minimal components, I can make a device that allows me to transmit Morse code wirelessly using radio frequency (RF) signals.

What I Will Need

How It Works

The Arduino acts as the brains of the transmitter, reading input from the Morse code key and turning the radio transmitter on and off rapidly to produce the Morse code patterns.

The NPN transistor acts as a switch, allowing the Arduino to control the higher current draw of the transmitter module. When the Arduino sets a pin high, it allows current to flow through the transistor to the transmitter's data pin, turning it on.

The resistor is used to limit current flow and prevent damage to the Arduino or transistor. The RF transmitter module generates the 433MHz signal which can be picked up by a receiver.

Circuit Diagram

Here is a circuit diagram showing how to connect the components:

How to Build a Simple Arduino Morse Code Transmitter From Scratch

The Morse key or button connects to a digital pin on the Arduino, the transistor base to another pin, and the emitter to ground. The collector connects to the data pin on the transmitter module.

Steps to Build

1. Prepare the Components

2. Connect the Morse Key

3. Connect the Transistor

4. Connect the RF Transmitter

5. Load and Test the Code

If using a receiver module, tune it to the same 433MHz frequency and verify the transmissions. Now I have a wireless Morse code transmitter to practice sending messages!

Going Further

To take this project further:

With just a few basic components, the Arduino is a handy platform for learning Morse code and radio communication. This simple transmitter is the perfect starting point before moving on to more advanced projects! Let me know if you build your own.