v1.5.0 - Sub-Hz Frequency Precision & Improved GUI

What's New in v1.5.0

🎯 Sub-Hz Frequency Precision

• Frequency is now stored as double - no more 198 Hz PLL quantization visible to user
• Firmware automatically splits frequency into PLL steps + DSP complex carrier rotation
• Set any frequency like freq 2400100050.5 and it works!

🖥️ GUI Improvements

• TX ON/OFF button with green color when transmitting
• PPM slider (-2 to +2 ppm) with immediate response
• Scroll wheel tuning (50 Hz per step, toggleable with checkbox)
• QO-100 downlink frequency display (shows 10489.xxx MHz next to uplink)
• All sliders now respond immediately (no delay/debounce)

📻 New Commands

• tx 0|1 - Enable/disable TX (SSB modulation)

🔧 Optimized DSP Defaults

Updated default values for better voice quality:

Parameter	Old	New
Bandpass low	200 Hz	50 Hz
EQ low shelf	-9.5 dB	-2.0 dB
Compressor threshold	-12.5 dB	-2.5 dB
Output limit	0.312	0.940
Amp gain	4.36	2.9

📥 Installation

1. Download SX1280SDR.uf2 below
2. Hold BOOTSEL on Pico and connect USB
3. Copy UF2 to RPI-RP2 drive

Full Changelog: v1.4.1...v1.5.0