c/ghetto-sound-system/ftdi-midi.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <alsa/asoundlib.h>
   4 #include <ftdi.h>
   5
   6
   7 #define BAUD 31250
   8
   9 static snd_rawmidi_t *midi_in, *midi_out;
  10 struct ftdi_context ftdi;
  11
  12 int main(void) {
  13
  14
  15         snd_rawmidi_open(&midi_in, &midi_out, "virtual", SND_RAWMIDI_NONBLOCK);
  16         //snd_rawmidi_open(&midi_in, &midi_out, "virtual", 0);
  17
  18
  19         if (ftdi_init( &ftdi )) {
  20                 fprintf(stderr,  "usb - init error !\n");
  21                 return 1;
  22         }
  23
  24         if (ftdi_usb_open(&ftdi, 0x0403, 0x6001)) {
  25                 fprintf(stderr,  "usb - open error (cannot find?) !\n");
  26                 fprintf(stderr, "ftdi_usb_open failed, error (%s)\n", ftdi_get_error_string(&ftdi));
  27                 ftdi_deinit( &ftdi );
  28                 return 2;
  29         }
  30
  31         if (ftdi_usb_reset( &ftdi )) {
  32                 fprintf(stderr,  "usb - reset error !\n");
  33                 ftdi_usb_close( &ftdi );
  34                 ftdi_deinit( &ftdi );
  35                 return 3;
  36         }
  37
  38         ftdi_disable_bitbang( &ftdi );
  39         ftdi_set_baudrate(&ftdi, BAUD);
  40
  41         unsigned char buf;
  42         int ret;
  43         while(1) {
  44                 //FTDI2MIDI
  45                 ret = ftdi_read_data(&ftdi,&buf,1);
  46                 if(ret < 0) break;
  47                 if(ret > 0) snd_rawmidi_write(midi_out, &buf, 1);
  48
  49                 //MIDI2FTDI
  50                 ret = snd_rawmidi_read(midi_in,&buf,1);
  51                 if(ret < 0 && ret != -EAGAIN) break;
  52                 if(ret > 0) ftdi_write_data(&ftdi, &buf, 1);
  53
  54                 usleep(1000);
  55         }
  56         exit(0);
  57 }