Web Control + Signal Visualization fork

[gorucommit]

Been playing a bit with the firmware fork so just wanted to show off some changes I've made:

1. Web Control on Wi-Fi

Features:

• Control main radio functions
• 1 minute long signal history
• Carry out full band scan, leaves selectable markers on the band display. (Needs more work)
• Broadcast and amateur areas of the band distinguished by coloured horizontal lines.
• Responsive design, renders well on desktop & phone. Max concurrent clients: 3.

Technical side:

• REST API for commands (POST endpoints)
• Server-Sent Events (SSE) for real-time status updates. State diffing + throttling + JSON caching for responsiveness & efficiency
• Thread-safe command queue pattern
• Async web server runs in its own task
• State-change detection + throttling to reduce CPU-usage for web-ui tasks
• HTML Build system: minified → gzipped → C header → PROGMEM

Web control quick demo: https://www.youtube.com/watch?v=930TWz-X-wo

2. Signal scale UI: Third UI layout option

• Signal strength bars drawn on bottom frequency scale after band scan
• Uses both SNR and 'RSSI-above-baseline' for more accurate representation (still needs some work)
• Only appears when scan data is available
• Horizontal lines to mark broadcast ranges and amateur ranges in MW & SW

3. General Improvements:

• MW band markers respect user's step selection (Europe 9kHz vs US 10kHz)
• Startup improvements: parallelized SI4732 + display init, slightly deferred WiFi/BLE connection, immediate splash display (I prefer a screen to give me the illusion of faster start-up times)
• Timer overflow safety
• Code deduplication in draw and across all layouts

4. Things I will continue working on:

• Figuring out a better algorithm and better way to display and use markers. Ultimately, I might create a unified marker system provoked by band scan and by seek. Will probably change more things on the UI of seek and band scan. ETM-style scan limited to key parts of the band when on a non-SSB band? Maybe, maybe not.
• Making the web control UI signal meters more useful.
• Adding found frequencies from band scan / seek into an easily navigable list on the web-ui (on the radio too, eventually). Integrating Eibi and RDS to such list.
• I might start messing with the encoder controls to make the things I use most often simpler to access: mute, seek, save/recall from memory.
• Focusing on the SSB side on the web-ui (not touched yet)