 
   unsigned long bpm_to_us(uint8_t bpm)
   {
-    return 6000000 / (unsigned long)bpm;
+    return 750000 / (unsigned long)bpm;
   }
 
   void display_slew_rate(int16_t x, int16_t y, uint8_t rate, DUINO_SSD1306::SSD1306Color color)


class DU_SEQ_Function : public DUINO_Function {
 public:
  DU_SEQ_Function() : DUINO_Function(0b0111110000) { }
  
  virtual void setup()
  {
    gt_attach_interrupt(GT3, clock_isr, CHANGE);
    gt_attach_interrupt(GT4, reset_isr, RISING);


 private:
  void update_clock()
  {
    Timer1.detachInterrupt();
    if(!seq_values.clock_ext)
    {
      Timer1.attachInterrupt(clock_isr, seq_values.clock_period);
    }
  }

