FPGA Morse Code Signal Processor

📌 Project Overview

This project is a digital logic system implemented on the Basys 3 FPGA (Artix-7) that performs real-time Morse code decoding.

Designed using Structural Verilog, the system utilizes a hierarchical modular architecture to capture asynchronous user inputs (dots/dashes), process them through a shift-register memory, and decode them into alphanumeric characters on a 7-segment display. It features a custom "Siekoo" font to ensure confusion-free character visualization.

⚙️ Logic Architecture

The design relies on a modular data flow rather than a single monolithic block.

Key Modules:

• DotOrDashDecoder: Distinguishes between short presses (<200ms) and long holds (>200ms) using a 4-bit counter for signal duration analysis.
• ShiftRegister: A 10-bit serial-in/parallel-out register that stores the incoming sequence of dots (00) and dashes (01).
• Translate: A combinational logic tree that maps the 10-bit shift register state to a unique 6-bit character code.
• SevenSeg: Custom display driver utilizing the 'Siekoo' alphabet to render 0-9 and A-Z legibly on the hardware.
• ClockDivider: Cascaded frequency dividers to step down the 100MHz system clock for human-scale timing.

🚀 Key Features

• Visual Input Verification: Uses led[4:3] to provide real-time feedback on signal registration (Dot vs. Dash) before the user releases the button.
• Deep Memory: Capable of storing and decoding sequences up to 5 inputs long.
• Safety Reset: Implements a Hold-to-Clear mechanism on BtnD to prevent accidental memory flushing.
• Visual Debugging: Maps internal states (Counter value, Shift Register content) to the on-board LED array for real-time logic verification.

🛠 Hardware Stack

• Board: Digilent Basys 3
• FPGA: Xilinx Artix-7 (XC7A35T)
• Language: Verilog (Structural/Modular)
• Toolchain: Xilinx Vivado

📖 Usage

1. Enable: Flip sw[0] HIGH to arm the system.
2. Input: Press BtnU and watch led[4:3] for feedback:
   • Dot: Release when led[3] illuminates (Short press).
   • Dash: Release when led[4] illuminates (Long press).
3. Reset: Press BtnD to clear the shift register and counter.
4. Output: The 7-segment display will update in real-time as the sequence is built.