Morse Code Interpreter

The morse code interpreter.

The Challenge: The assignment was to create a telegraph key to be used to communicate with a partner across the room. I took this several steps further, and challenged myself to create a machine that would interpret my partner’s Morse Code message and display it on a screen.

Technical Approach: The heart of my device was a small computer-on-a-chip produced by a company called Parallax. I taught myself how to program this computer to listen for the telegraph key to be pressed, and then to interpret the signal as a dot or a dash depending on how long the key was held down. The chip then converted the series of dots and dashes into characters by looking up the Morse Code letters in a table. The computer then displayed this information on a screen.

Selected Design Features: To maximize usability, I included a switch which allows the user to plug the unit into a wall outlet through a power adapter, or to get power from internal batteries. I also mounted red and yellow LEDs on the front panel, allowing the user to visually identify dots and dashes as they are interpreted by the onboard computer. To improve visibility, I decided to use an inverse yellow and black display, allowing the yellow letters to shine through the black background.

The Startup Splash Screen The Device Opened
The startup splash screen. With the rear panel removed.
Internal View of Casing The Back Panel
An internal view of the front panel. The circuit board mounted to the rear panel.
The PCB The rear panel
The heart of the machine... powered by a Parallax BS2SX. Dry-transfer decals and an acrylic stand.