TouchRTTY v1.72 Stable

🚀 Release: TouchRTTY v1.72 (Stable)

This release marks the successful completion of Phase 3 — delivering a professional, standalone RTTY (Radioteletype) DSP decoder powered by the Raspberry Pi Pico 2 (RP2350).

The demodulator mathematics have been refined to match desktop SDR software standards (like fldigi), ensuring highly stable reception even under severe selective fading and noise.

📡 DSP Engine Highlights (Core 0)

• Absolute Timing (Anti-Jitter): Strict 10,000 Hz (+100 µs) sample rate enforcement, entirely eliminating phase drift.
• Continuous DPLL: A full Proportional-Integral (PI) loop with an integrated frequency error memory. Flawless reception of tight 1.0 stop-bit streams.
• Digital AGC: Automatic amplification of weak signals (up to 46 dB / x200 gain) before filtering.
• Logarithmic Squelch (dB): Intelligent hysteresis squelch calculating the true SNR. Opens only on valid signals (> 12 dB above noise).
• LSB Standard: Strict adherence to the Lower Sideband standard (Mark = lower frequency).

🖥️ User Interface & System (Core 1)

• True Lissajous Figures: The SCOPE mode renders crossed phase ellipses for Mark and Space.
• Safe Flash Storage: All settings are saved to internal Flash using multicore_lockout to prevent CPU stalls.
• Professional Refactoring: Display driver renamed to ili9488_driver for architectural clarity.
• Factory Reset: Supports both software menu reset and hardware reset (GPIO 4).

💾 Installation

1. Download the attached TouchRTTY_v1.72.uf2 file.
2. Hold BOOTSEL on your Pico 2, connect to PC, and drop the file onto the RP2350 drive.