Digital Radio for Raspberry Pi (DAB+ / FM + RDS)

DAB+ and FM receiver for the Raspberry Pi with the uGreen (Si4689) board: full web UI, correctly decoded RDS, MP3/WAV recording, FM scan with real station names, manual FM tuning and automatic start at boot.

An improved fork of RASPIAUDIOadmin/Digital-Radio-for-Raspberry-Pi, adapted and fixed for the uGreen DAB/FM board.

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Features

• DAB+: scan, 150+ stations, labels decoded in EBU Latin (correct names: "Radio Libertà", "#RTL102.5 napulè"...), live DLS artist/title, firmware 6.0.9 tested
• FM: scan with the real RDS station names, full RadioText, PI, PTY
• RDS decoded at the root (no heuristics): PS segment = block B bits 1-0, RT segment = block B low nibble, BLER filtering of corrupted blocks
• Manual FM tuning: type a frequency (87.5–108 MHz) right from the web UI
• MP3 or WAV recording named YYYYMMDD-HHMMSS_<mode>_<station>.mp3 with delete from the web UI
• Simultaneous listening + recording thanks to the shared ALSA device (dabdsnoop)
• Web UI: DAB and FM only (no HD/AM), per-mode metadata panel (DAB → artist/title/live text; FM → RT/PI/PTY), 4-column station layout
• One-command installation (install.sh) on a fresh Raspberry Pi OS
• Autostart at boot (systemd service)

Hardware requirements

• Raspberry Pi 3/4/5 with Raspberry Pi OS (bookworm or newer)
• uGreen DAB/FM board (Si4689), RST on GPIO 23 (original raspiaudio shield: RST on GPIO 25 and overlay adau7002-simple)
• FM/DAB antenna connected

Quick install

unzip digital-radio-pkg.zip
cd digital-radio-pkg
sudo ./install.sh
sudo reboot

After the reboot open http://<ip-of-the-pi>:8686, pick DAB or FM and press Scan stations.

The package also ships uninstall.sh and a full README.md with the configuration options (RST_PIN, OVERLAY, PORT, RECORD_FORMAT).

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What we changed

Every change was developed and verified empirically on the real hardware (uGreen board + Raspberry Pi).

RDS decoding (the main work)

Before	After
Rotated/garbled PS ("LOMBD.", "RTL1 .5")	Correct, stable PS: "RADIO 24", "RTL102.5", "LOMBARD.", "*Radio2"
Mixed-up RT ("(2009) *ORRESANGICeluono")	Clean RT: "GIGI D'ALESSIO - MEZZE VERITA'", "PAOLA & CHIARA - FESTA TOTALE"
—	PI and PTY (with type name) shown in the UI

How: the Si4689 chip already reports RDS characters as plain ASCII bytes in the blocks (no 6-bit table needed). The segment field was in the wrong place:

1. PS segment = block B bits 1-0 (verified on 120 samples: the "RT"/"L1"/"02"/".5" pairs are placed by B & 0x3 → "RTL102.5")
2. RT segment = block B low nibble (B & 0xF; the initial block-C hypothesis was a coincidence on a single station)
3. BLER filter on corrupted blocks — official kernel mapping: A=bits 7-6, B=bits 5-4, C=bits 3-2, D=bits 1-0 (our first version was inverted and let ~1 character in 40 through corrupted)
4. RadioText reset on text change (stale segments used to stay mixed in) and padding stop (all-space segments)

FM scan with real names

• During the scan every found station stays tuned ~2.5 s to capture its RDS PS → the list shows "CAPITAL", "DEEJAY", "MileniuM", "RADIO 24"...
• Plus BLER filtering and a full dwell for a stable name

Recording and audio

• MP3 recording (--record-format mp3, pipeline arecord | ffmpeg libmp3lame 128k) in addition to WAV
• Shared ALSA device dabdsnoop (/etc/asound.conf, dsnoop S16_LE 48 kHz): without it, simultaneous listening and recording failed ("Device or resource busy"); S16_LE is mandatory on the uGreen (the automatic dsnoop in S32_LE yields no data)
• Recording deletion from the web UI (DELETE /api/recordings/...)

Web UI

• Simplified modes: DAB and FM only (HD and AM removed)
• Per-mode metadata panel: DAB → Artist/Title/Live text; FM → RT, PI, PTY
• Manual FM tune (frequency input + Tune button, visible in FM mode only)
• Artwork with full text (the PS used to be truncated to 4 characters), 4-column station layout, 3-column recordings
• English labels, fixed alignments and spacing

uGreen platform

• --rst-pin 23 (the raspiaudio shield default of 25 does not reset the uGreen)
• ugreen-dabboard overlay in config.txt
• Firmware DAB 6.0.9 (tested; rom00_patch.016 identical across boards)

Autostart and distribution

• systemd service raspiaudio-radio.service with the correct command, enabled at boot (the "Start server automatically" switch in the UI shows active)
• The old dabradio project removed from autostart
• Installation package with an automated install.sh, tested on a wiped Raspberry Pi: packages, config.txt (SPI/I2S/overlay), asound.conf, project at /opt/digital-radio, service enabled

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Useful commands

# manual start (without systemd)
python3 radio.py serve --port 8686 --rst-pin 23 --i2s-master \
  --record-device dabdsnoop --record-format mp3

# service
sudo systemctl status raspiaudio-radio
sudo systemctl restart raspiaudio-radio

Acknowledgements and license

Based on RASPIAUDIOadmin/Digital-Radio-for-Raspberry-Pi (no license declared in the original repository — all rights on the original code remain with its authors). The changes in this fork are for personal/hobby use.