csbluechip / esp32_rtttl

RTTTL (Nokia ringtone format) player for ESP32(-S2) PWM

Play RTTTL (Nokia Ringtones)

Plays an RTTTL string via a piezo speaker using PWM.

LED will blink on/off with each note.

1. Set target : idf.py set-target esp32s2
2. Choose GPIO pins: idf.py menuconfig ...see RTTTL Configuration
3. Build demo : idf.py build
4. Flash to ESP32 : idf.py -p /dev/ttyUSB0 -b 115200 flash

Here are 10,825 example RTTTL tunes also available on archive.org

RTTTL Format Specification

RTTTL (RingTone Text Transfer Language) is the primary format used to distribute 
ringtones for Nokia phones. 

An RTTTL file is a text file, containing three colon-separated sections:
	# ringtone name
	# control section
	# comma separated sequence of tone commands
Arbitrary use of whitespace is valid.

Format
	[name]:[control[,control[,control]]]:tone[,tone[,...]]

	name    : ASCII ringtone name, max 10 characters

	control : tag=val
		tag : b = BPM*                  .. see below*      default = 63
		      d = default tone Duration .. {1,2,4,8,16,32} default = 4
		      o = default tone Octave   .. {4,5,6,7}       default = 6
			  
		* A "beat" is (generally) a "quarter note" 
		  Valid BPMs are { 25,  28,  31,  35,  40,  45,  50,  56,  63,
		                   70,  80,  90, 100, 112, 125, 140, 160, 180,
		                  200, 225, 250, 285, 320, 355, 400, 450, 500,
		                  565, 635, 715, 800, 900}

	tone     : [dur]note[oct][dot]
		dur  = note duration {1,2,4,8,16,32} .. 4=one-beat, 8=half-beat, etc.
		note = note name {a,a#,b,c,c#,d,d#,e,f,f#,g,g#,p} .. p = pause/rest
		oct  = octave {4,5,6,7} .. A4 = 440Hz*
		dot  = increase duration by 50%

		* Total note range (of Nokia 61xx) is {a4..b7} (39 notes)

	Example: 
		Simpsons : d=4,o=5,b=160 : 32p,c.6,e6,f#6,8a6,g.6,e6,c6,8a,8f#,8f#,8f#,2g

Wiring

The default code uses the onboard LED to flash when notes are played.

The only thing you need to do is add a Piezo Buzzer:

ESP32/GPIO:2 --[red]--> 220ohm resistor ----> Piezo Buzzer --[black]--> Gnd

...I'm not convinced the resistor is necessary, but probably safer that way.

Notes

I'm new to the ESP IDF, so I don't really know what most of the files are that I inherited from using the 'blink' example as a starting point ...All the real work is in main/rtttl.c