FmRadioStreamer

Raspberry Pi based FM streamer with OLED, buttons and LEDs support.

Building

Clone this repository, run go get and then go build. Of course, you have to install Go first.

If you want to build for other device (e.g. build on Windows and run on RaspberyPi), use cross-compilation!

Environmental variables for RPi Zero: GOOS=linux;GOARCH=arm;GOARM=5. For other RPis, GOARM may be unnecessary.

Installation

Build or copy binary from releases tab. Copy install.sh to your directory, type chmod +x install.sh, then sudo ./install.sh.

WARNING! This script will install some unnecessary dependencies like Python for youtube-dl. If you already have working youtube-dl instance, edit the script (comment line #6).

Copy config.json.example, rename to config.json aned edit. Here you can get your YouTube API Key. Also, you have to add gpu_freq=250 in /boot/config.txt.

Running

Rename config.json.example to config.json. Then type sudo node index.js. You can change RDS in config.json file. Go to API Docs section for more.

Functions

• RDS and other options rendering on screen
• LEDs blinking when everything is OK
• Yellow LED blinking if frequency is out of limits
• Blue LED blinking if music is being processed (downloading, converting)
• Downloading music from YouTube
• Changing frequency with buttons
• Web dashboard

API docs

None. Please reverse-engineer pkg/dashboard for that. :(

Dependencies note

This project uses PiFmAdv, FFmpeg, libsndfile1-dev, youtube-dl and other stuff listed in go.mod.

Optional hardware

SSD1306 screen, 4 THT buttons, ~400 Ohm resistors, ~20k Ohm resistors, LEDs, female-male and male-male wires. Tested on Raspberry Pi Zero W Rev 1.1.

What if I don't have that hardware?

The minimum requirement is the RaspberryPi. FmRadioStreamer SHOULD work without any other peripherals.

Gallery

In the docs directory there are pictures of first version of this project. Watch on your own risk!

GPIO

• 1 - 3V3 Power
• 3 - GPIO 2 - screen
• 5 - GPIO 3 - screen
• 6 - GND - for screen
• 7 - GPIO 4 - antenna
• 26 - GPIO 7 - blue LED (audio conversion in progress)
• 29 - GPIO 5 - yellow LED (frequency out of limits)
• 31 - GPIO 6 - green LED
• 32 - GPIO 12 - button (screen color inversion)
• 33 - GPIO 13 - green LED
• 35 - GPIO 19 - green LED
• 36 - GPIO 16 - button (frequency multiplier switch)
• 37 - GPIO 26 - green LED
• 38 - GPIO 20 - button (frequency up)
• 39 - GND - for LEDs
• 40 - GPIO 21 - button (frequency down)

Which format should I chose?

Downloading and converting benchmark:

• Song URL: https://www.youtube.com/watch?v=SaoBbCC66I4
• Results:

Format	First run time	Second run time	File size
MP3	6:17	6:21	12 431 KB
WAV	4:20 hehe	4:17	6 499 KB
Opus	3:32	3:38	69 891 KB

For pretty good audio quality, low file size and best conversion time, use Opus. If for some reason you can't use Opus format and have outdated libsndfile1-dev package, use WAV. Use MP3 if you don't want to re-encode your existing music library.

MP3 support

1. Update your RPi (optional, but recommended).

sudo bash -c 'for i in update {,dist-}upgrade auto{remove,clean}; do apt-get $i -y; done'

2. Edit /etc/apt/sources.list file using your favourite editor, for example sudo vim /etc/apt/sources.list. In my case, the file looks like this:

deb http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
# Uncomment line below then 'apt-get update' to enable 'apt-get source'
#deb-src http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi

Replace bullseye with bookworm.

deb http://raspbian.raspberrypi.org/raspbian/ bookworm main contrib non-free rpi

3. Run sudo apt update. It wil say that 69420 packages can be updated - ignore that.
4. Run sudo apt install libsndfile1-dev. It will update only this package and its dependencies.
5. Confirm that libsndfile1-dev is now version 1.1.0 or later. Run sudo apt-cache policy libsndfile1-dev. My output:

libsndfile1-dev:
  Installed: 1.1.0-2 
(...)

5. Repeat step 1, but now revert bookworm to bullseye. Done. 🎉

JSON settings

Option	Description	Type (additional info)	Default	Notes
freq	Frequency in MHz	number (float64)	108.0
format	Audio format for saved files	string	opus	limited to libsndfile1-dev: "wav" available, "mp3" only if it is upgraded to 1.1.0+
multiplier	Frequency multiplier (used when using physical buttons)	number (float64)	0.1
PS	RDS station name	string (len: 8)	FmRadStr
RT	RDS station text	string (len: 64)	RPi based radio streamer. It is working!
PI	RDS station ID	string (len: 4, hex)	FFFF
TP	RDS traffic programme	string	(empty string)	I don't know the type of this setting.
PTY	RDS programme type	number (uint)	0	Warning: different meaning in EU and US! Range: 0-31.
ytApiKey	YouTube API V3 Key	string	(empty string)
port	Web dashboard port	number (uint16)	80
power	RaspberryPi output power	number (uint8)	5	Refer to PiFmAdv for more info.
mpx	Mpx output power ("volume")	number (uint)	30	See above.
preemph	pre-emphasis	string	eu	Possible values: "eu", "us".
antennaGPIO	GPIO antenna header	number (uint8)	4	Possible values: 4, 20, 32, 34
ssd1306	OLED screen type SSD1306 enabled	bool	true
dynamicRT	Switching RT between that saved in config and current playing audio filename	bool	true
dynamicRTInterval	Dynamic RT switching interval in seconds	number (uint)	20
verbose	Additional logs in console	bool	false