#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.

Build

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

Designed with Fritzing: see RandomCodePractice.fzz.

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)

schematic

First testing the circuit on a breadboard:

bb_build

Code & Libraries

Main sketch: RandomCodePractice.ino

Libraries:

Arduino Wire library
LiquidCrystal_I2C - LCD over I²C
Morse.h / Morse.cpp
- 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

In the first version of the build, I switched the Uno for an Arduino Nano and mounted it all in a suitably sized chocolate box. This version didn’t have the output jack.

internal_build