#567 Random Code Practice

A simple Morse code practice generator that prints the character and sounds the dit-dahs to a speaker. Based on a project by Glen Popiel KW5GP.

Here’s a quick demo..

Notes

Glen Popiel’s Arduino for Ham Radio is a great little collection of ham radio-adjacent projects that not only provides some good project inspiration but also presents them in a way that is easy to follow no matter one’s level of Arduino experience.

This project is an adaptation/enhancement of a simple Morse code practice generator:

• it selects a random character
• displays the character on an LCD
• and sounds the Morse code to a piezo speaker
• the speed can be adjusted with a variable resistor

I’ve extended and revised the code to add some new features:

• a switch to select between all character / alpha only / numbers only
• display the actual dit-dah Morse representation on the screen as well as the character being sounded

Construction

A SPDT Centre Off switch is used as a tri-state toggle for the character select:

• ON: pulled high (alpha only)
• CENTRE: VCC/2 voltage divider (all characters)
• OFF: pulled low (numbers only)

First testing the circuit on a breadboard:

Code & Libraries

• Arduino Wire library
• LiquidCrystal_I2C - LCD over I²C
• Morse - Morse encoding by Erik Linder SM0RVV and Mark VandeWettering K6HX.
  • I cannot find a link to the original source (Version 0.2), so it is included in the project folder.
  • Includes Glen Popiel KW5GP’s fixes for Morse encoding
  • extended by me to allow dynamic speed adjustment

Putting it in a Box

For a final build, I switched the Uno for an Arduino Nano and mounted it all in a suitably sized chocolate box.

Credits and References

• Arduino for Ham Radio - goodreads
• Arduino for Ham Radio - ARRL support page (book sources available)
• Morse code - wikipedia
• fun with morse code - presentation on learning CW by Anthony Luscre K8ZT