Day: December 12, 2014

Perhaps a set of buttons are easier to use than a slider for changing the key speed.

    struct mybutton mybuttons[100] = {
     {"CW",         0, 1, 0, 1},
     {"CW-REV",     0, 1, 1, 2},
     {"10 wpm",     1, 2, 0, 1},
     {"15 wpm",     1, 2, 1, 2},
     {"20 wpm",     1, 2, 2, 3},
     {"25 wpm",     1, 2, 3, 4},
     {"30 wpm",     1, 2, 4, 5},
     {"35 wpm",     1, 2, 5, 6},
     {"40 wpm",     1, 2, 6, 7}
    }
    for(int i=0;i<nbutton;i++) {
      button = gtk_button_new_with_label (mybuttons[i].name);
      gtk_signal_connect (GTK_OBJECT (button), "clicked", GTK_SIGNAL_FUNC (callback),
                          (gpointer) mybuttons[i].name);
      gtk_table_attach_defaults(GTK_TABLE(table), button,
                                mybuttons[i].left_attach, mybuttons[i].right_attach,
                                mybuttons[i].top_attach,  mybuttons[i].bottom_attach);
      gtk_widget_show (button);
    }

First you define lots of buttons, their labels and locations. IF one of the buttons is “clicked”, a callback routine is called.

void callback( GtkWidget *widget, gpointer data ) {
  gint   wpm;
  if(g_str_has_suffix((char *)data, "wpm")) {
   wpm = atoi( g_strndup((char *) data, 2) );
   set_cw_speed(wpm);
  }
}

If the label of a button ends with “wpm”, we have to change the key speed according to the first two digits.

void set_cw_speed(int wpm) {
  int outputcount = 9;
  static unsigned char command1[9] = {0xfe, 0xfe, 0x80, 0xe0, 0x14, 0x0c, 0x00, 0x32, 0xfd};
  int iii, i100, i10, i1;
  if(wpm <  6) wpm =  6;
  if(wpm > 48) wpm = 48;
  iii = 255 * (wpm - 6) / (48 - 6);
  i100 = iii / 100;
  i10  = (iii - 100*i100) / 10;
  i1   = iii % 10;
  command1[6] = i100;
  command1[7] = 16*i10 + i1;
  write(fd, &command1, outputcount);
}

Conversion from “wpm” to a command parameter is necessary. See IC-7410 Keyspeed for the details.