jRadio

An All-in-One Embedded Audio Station

jRadio transforms an ESP32-S3 module into a feature-packed audio workstation. Rather than requiring specialized single-purpose commercial hardware or multi-board setups, jRadio consolidates internet radio streaming, FM radio reception, network audio streaming (DLNA and Yandex Music), and local music playback from USB flash drives or microSD cards into a single cohesive player.

Designed to be built using readily available off-the-shelf components, jRadio is fully controllable via hardware rotary encoders, pushbuttons, infrared remotes, or directly through a web browser on a phone or desktop within the local network.

Playback Sources and Format Support

jRadio supports a wide array of multimedia inputs and container formats:

• Internet Radio: Manages up to 99 customizable radio stations with ICY stream metadata, album art parsing, and automatic reconnection on dropped connections over HTTP and HTTPS.
• Local File Playback: Reads audio files from USB Mass Storage (via USB Host) and microSD cards formatted in FAT16/FAT32. It supports .m3u, .m3u8, and .pls playlists as virtual folders, alongside .cue sheet splitting for single-file album rips.
• Audio Codecs: Plays MP3, AAC (ADTS streams), FLAC (including 24-bit streams), Ogg (FLAC, Vorbis, or Opus containers), and 16-bit uncompressed WAV files.
• Network Media & Cloud: Features integrated DLNA client capabilities with SSDP/SOAP discovery to browse local media servers, as well as native integration with Yandex Music (including personalized streams like “My Wave” and track feedback).
• FM Tuner Support: Supports RDA5807FP (I2S audio) and RDA5807M FM tuner modules with RDS station identification, radiotext display, frequency scanning, and preset management.
• Bluetooth Link: Integrates with an auxiliary ESP32 Bluetooth module running companion firmware for bidirectional audio (streaming from phones with track metadata and outputting to wireless speakers or headphones).

Hardware and Display Architecture

The firmware is targeted at the ESP32-S3 with 16 MB of Flash and 8 MB of octal PSRAM. Audio rendering is driven via I2S to external high-fidelity DACs such as the PCM5102, outputting 16-bit stereo audio with optional hardware amplifier mute control.

Visuals and user interaction are powered by LVGL v9, allowing high-performance UI rendering on SPI displays with orientation adaptability (portrait or landscape). Supported controller chips include:

• ILI9341 and ST7789 (320×240)
• ILI9488 and ST7796S (480×320)
• ST7789 ultra-wide displays (320×170, 1.9” modules)

jRadio allocates dedicated PSRAM memory pools (lvgl_pool) to keep graphics rendering smooth while maintaining enough dynamic headroom for network buffers, SSL handshakes, and audio decoders.

Software Design and Key Technologies

Developed under the ESP-IDF framework (v5.5.x) on top of FreeRTOS, jRadio uses a highly modular component architecture:

• FreeRTOS & lwIP: Manages concurrent networking, web socket communication, audio stream fetching, and GUI tasks without audio stutter.
• LittleFS & NVS: Stores configuration parameters, station metadata, Wi-Fi credentials, and learned IR codes in non-volatile flash memory.
• Embedded Web Server: Hosts a complete web UI providing real-time player controls, station list management with Radio Browser catalog search, icon fetching, system backup/restore, and remote control training.
• Everyday Utility Features: Includes clock synchronization via NTP or RTC hardware (DS3231/DS1307), weather reporting (Open-Meteo, wttr.in, or OpenWeatherMap), screensavers, deep-sleep standby, sleep timers, and weekday alarms that automatically wake the unit.

Web-Based Flashing and Provisioning

jRadio offers browser-based installation and configuration without requiring local toolchains. Users can select their display type, pinouts, and optional peripheral modules through a web tool using Web Serial to flash the firmware directly to the ESP32-S3 and configure initial Wi-Fi credentials via Improv Wi-Fi serial provisioning. For developers, standard ESP-IDF compilation and custom board configurations are maintained through dedicated CMake components and header definitions.