jim hamblen / Mbed 2 deprecated flash_audio_player

Plays audio samples from an array stored in flash. Values are from an audio *.wav file that was automatically converted to a C array data source file.

Dependencies:   mbed

See https://os.mbed.com/users/4180_1/notebook/using-flash-to-play-audio-clips/ for instructions

main.cpp@0:e4f991474a45, 2017-10-21 (annotated)

Committer:
4180_1
Date:
Sat Oct 21 20:53:36 2017 +0000
Revision:
0:e4f991474a45
ver 1.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
4180_1 0:e4f991474a45 1 #include "mbed.h"
4180_1 0:e4f991474a45 2 AnalogOut speaker(p18);
4180_1 0:e4f991474a45 3 Ticker sampletick;
4180_1 0:e4f991474a45 4 DigitalOut myled(LED1);
4180_1 0:e4f991474a45 5 //Plays Audio Clip using Array in Flash
4180_1 0:e4f991474a45 6 //
4180_1 0:e4f991474a45 7 //setup const array in flash with audio values
4180_1 0:e4f991474a45 8 //from free wav file conversion tool at
4180_1 0:e4f991474a45 9 //http://ccgi.cjseymour.plus.com/wavtocode/wavtocode.htm
4180_1 0:e4f991474a45 10 //see https://os.mbed.com/users/4180_1/notebook/using-flash-to-play-audio-clips/
4180_1 0:e4f991474a45 11 #include "cylonbyc.h"
4180_1 0:e4f991474a45 12
4180_1 0:e4f991474a45 13 #define sample_freq 11025.0
4180_1 0:e4f991474a45 14 //get and set the frequency from wav conversion tool GUI
4180_1 0:e4f991474a45 15 int i=0;
4180_1 0:e4f991474a45 16
4180_1 0:e4f991474a45 17 //interrupt routine to play next audio sample from array in flash
4180_1 0:e4f991474a45 18 void audio_sample ()
4180_1 0:e4f991474a45 19 {
4180_1 0:e4f991474a45 20 speaker.write_u16(sound_data[i]);
4180_1 0:e4f991474a45 21 i++;
4180_1 0:e4f991474a45 22 if (i>= NUM_ELEMENTS) {
4180_1 0:e4f991474a45 23 i = 0;
4180_1 0:e4f991474a45 24 sampletick.detach();
4180_1 0:e4f991474a45 25 myled = 0;
4180_1 0:e4f991474a45 26 }
4180_1 0:e4f991474a45 27 }
4180_1 0:e4f991474a45 28 int main()
4180_1 0:e4f991474a45 29 {
4180_1 0:e4f991474a45 30 while(1) {
4180_1 0:e4f991474a45 31 myled = 1;
4180_1 0:e4f991474a45 32 //use a ticker to play send next audio sample value to D/A
4180_1 0:e4f991474a45 33 sampletick.attach(&audio_sample, 1.0 / sample_freq);
4180_1 0:e4f991474a45 34 //can do other things while audio plays with timer interrupts
4180_1 0:e4f991474a45 35 wait(10.0);
4180_1 0:e4f991474a45 36 }
4180_1 0:e4f991474a45 37 }