Laser-Harp

FluidSynth_Test_02_GPIO_INPUT_SINGLE_NOTE.c

 // FluidSynth_Test_02_GPIO_INPUT_SINGLE_NOTE.c

 // http://fluidsynth.sourceforge.net/api/
 // http://www.i-programmer.info/programming/hardware/8744-exploring-edison-mraa-gpio.html?start=3
 // http://www.malinov.com/Home/sergey-s-blog/inteledison-simplei2saudiosetup

 // Compile with this
 // gcc FluidSynth_Test_02_GPIO_INPUT_SINGLE_NOTE.c -o FluidSynth_Test_02_GPIO_INPUT_SINGLE_NOTE -lmraa -L/usr/local/lib -lfluidsynth

 #include "mraa.h"
 #include <stdio.h>
 #include <unistd.h>
 #include <time.h>
 #include <fluidsynth.h>

 #define INPUT_PIN 4
 #define BILLION 1000000000L

 struct timespec btime, etime;__time_t i;

 // MRAA_GPIO_EDGE_NONE = 0,
 // MRAA_GPIO_EDGE_BOTH = 1,
 // MRAA_GPIO_EDGE_RISING = 2,
 // MRAA_GPIO_EDGE_FALLING = 3

 fluid_synth_t* synth;
 fluid_audio_driver_t* adriver;

 // function prototypes
 void switchPressed(void* pin);
 void createsynth();
 void deletesynth();
 void loadsoundfont();

 int main(int argc, char** argv) {
   mraa_init();
   mraa_gpio_context inputPin = mraa_gpio_init(INPUT_PIN);
   mraa_gpio_dir(inputPin, MRAA_GPIO_IN);
   mraa_gpio_isr(inputPin, MRAA_GPIO_EDGE_BOTH, &switchPressed, inputPin);

   createsynth();
   loadsoundfont();

   for (;;) {}

   deletesynth();

   return MRAA_SUCCESS;
 }

 void switchPressed(void* pin) {
   struct timespec ttime;

   clock_gettime(CLOCK_REALTIME, &ttime);
   usleep(500);

   int s = mraa_gpio_read((mraa_gpio_context) pin);

   if (s == 0) {
     btime = ttime;

     /* Release the note on key 60 */
     fluid_synth_noteoff(synth, 0, 60);
     printf("time = %f (s)\n", btime);
     printf("fluid_synth_noteoff(synth, 0, 60);\t/* Release the note on key 60 */\n");
   }
   else {
     double nseconds = (double)((ttime.tv_sec - btime.tv_sec) * BILLION) + (double) (ttime.tv_nsec - btime.tv_nsec) ;
     printf("time = %f (s)\n", nseconds / BILLION);
     /* Play a note on key 60 with velocity 100 on MIDI channel 0 */
     printf("fluid_synth_noteon(synth, 0, 60, 100);\t/* Play a note on key 60 with velocity 100 on MIDI channel 0 */\n");
     fluid_synth_noteon(synth, 0, 60, 100);
   }
 }

 void createsynth() {
   fluid_settings_t* settings;
   settings = new_fluid_settings();
   fluid_settings_setstr(settings, "synth.reverb.active", "yes");
   fluid_settings_setstr(settings, "synth.chorus.active", "no");
   fluid_settings_setint(settings, "audio.period-size", 384);
   fluid_settings_setnum(settings, "synth.sample-rate", 48000);
   synth = new_fluid_synth(settings);
   adriver = new_fluid_audio_driver(settings, synth);
 }

 void deletesynth() {
   delete_fluid_audio_driver(adriver);
   delete_fluid_synth(synth);
 }

 void loadsoundfont() {
   fluid_synth_sfload(synth, "/home/root/audio/audio_files/FluidR3_GM2-2.SF2", 1);
 }