(0014) // user defined beep 
(0015) // in: Frequency in 1-10 kHz and duration in ms
(0016) void buzzer_beep (unsigned char freq, unsigned int duration)  //
(0017)  {
(0018)    unsigned int ticks, i;	 	   // 0,0015ms/delay(x)
(0019)  
(0020)   //delay[ms] = (1000/f) / 2
(0021)   //delay[ticks] = ((1000/f) / 2) * 667 ticks/ms
(0022)   
(0023)    ticks = ((int)((100/freq)/2)*6); // not exactly (+5% in freq...) max=300
    03CD 2D2C      MOV	R18,R12
    03CE 2733      CLR	R19
    03CF E604      LDI	R16,0x64
    03D0 E010      LDI	R17,0
    03D1 940E18F1  CALL	div16s
    03D3 E022      LDI	R18,2
    03D4 E030      LDI	R19,0
    03D5 940E18F1  CALL	div16s
    03D7 0198      MOVW	R18,R16
    03D8 E006      LDI	R16,6
    03D9 E010      LDI	R17,0
    03DA 940E19B0  CALL	empy16s
    03DC 0168      MOVW	R12,R16
(0024)   
(0025)   // duration: 667*ticks from delay(ticks) per ms // max 5s@10kHz, 50s@1kHz
(0026)   
(0027)    i = ((long)duration*334)/ticks;  // 
    03DD 0115      MOVW	R2,R10
    03DE 2444      CLR	R4
    03DF 2455      CLR	R5
    03E0 E44E      LDI	R20,0x4E
    03E1 E051      LDI	R21,1
    03E2 E060      LDI	R22,0
    03E3 E070      LDI	R23,0
    03E4 925A      ST	R5,-Y
    03E5 924A      ST	R4,-Y
    03E6 923A      ST	R3,-Y
    03E7 922A      ST	R2,-Y
    03E8 018A      MOVW	R16,R20
    03E9 019B      MOVW	R18,R22
    03EA 940E19C0  CALL	empy32u
    03EC 0116      MOVW	R2,R12
    03ED 2444      CLR	R4
    03EE 2455      CLR	R5
    03EF 925A      ST	R5,-Y
    03F0 924A      ST	R4,-Y
    03F1 923A      ST	R3,-Y
    03F2 922A      ST	R2,-Y
    03F3 940E192D  CALL	div32s
    03F5 0158      MOVW	R10,R16
    03F6 C008      RJMP	0x03FF
(0028)   
(0029)    while (i--)  			// 1000*0,5ms = 0,5s
(0030)    {
(0031)      delay(ticks);  	  	// approx 0.25ms delay
    03F7 0186      MOVW	R16,R12
    03F8 940E06AA  CALL	_delay
(0032)      buzzer_on();
    03FA 98C1      CBI	0x18,1
(0033) 	 delay(ticks);
    03FB 0186      MOVW	R16,R12
    03FC 940E06AA  CALL	_delay
(0034) 	 buzzer_off();
    03FE 9AC1      SBI	0x18,1
    03FF 0115      MOVW	R2,R10
    0400 01C1      MOVW	R24,R2
    0401 9701      SBIW	R24,1
    0402 015C      MOVW	R10,R24
    0403 2022      TST	R2
    0404 F791      BNE	0x03F7
    0405 2033      TST	R3
    0406 F781      BNE	0x03F7
    0407 940E19F6  CALL	pop_gset4
    0409 9508      RET
(0035)    }
(0036)  }