meguitarist
New Member
Good day everyone.
I'm a beginner in electronics & PICs even new to this Forum.
I've compiled this coding & wondering someone can point me how can I calculate the required frequency & timing for this project using internal 4MHz oscillator
I need the sound to be raise from 500Hz to 1200Hz & falling again to 500Hz repeat forever.
change the constant value it changed the tone & timing too. How I know what is the frequency that I'm playing & the timing that repeated?
;Project: Siren Sound
List P = 12F675
#include <p12F675.inc>
__CONFIG _CP_OFF & _PWRTE_ON & _WDT_OFF & _INTRC_OSC_NOCLKOUT & _MCLRE_ON & _BODEN_ON
#define OUT GPIO,0 ;port pin defined as the actual output
errorlevel -302
;VARIABLES
Cycles EQU 20H ;holds # of cycles
Steps EQU 21H ;holds # of steps
Freq EQU 22H ;holds frequency variable
Counter EQU 23H ;variable used as counter
Counter1 EQU 24H ;variable used as counter
;CONSTANTS
N_cycles EQU .5 ; number of cycles
N_steps EQU .25 ; number of steps
N_freq EQU .170 ; constant that determines frequency
;********************************************************************
ORG 0 ;This is the start of memory for the program.
Setup: CLRF GPIO ;all outputs are zeroed
MOVLW 07H ;GPIO2:0 are digital IO
MOVWF CMCON ;
BSF STATUS,RP0 ;Go to Bank 1
CLRF ANSEL ;all digital IO
CLRF TRISIO ;Make all port output
BCF STATUS,RP0 ;Go to Bank 0 - the program memory area.
Siren: MOVLW N_cycles ;Number of cycles for each tone
MOVWF Cycles ;
MOVWF Counter1 ;
MOVLW N_steps ;Number of steps
MOVWF Steps ;File 0F holds the number of steps
MOVLW N_freq ;Determines frequency
MOVWF Freq ;File 0C determines the frequency
Repeat: MOVF Freq,W ;File 0C is moved to W
MOVWF Counter ;W is moved to file 0D for decrementing
On: BSF OUT ;Length of HIGH time to Piezo
DECFSZ Counter,F
GOTO On
MOVWF Counter ;W is moved to file 0D again
Off: BCF OUT ;Length of LOW time to Piezo
DECFSZ Counter,F ;
GOTO Off
DECFSZ Counter1,F ;Number of cycles for each tone
GOTO Repeat ;Go to repeat
DECF Freq,F ;HIGH and LOW is shortened -tone rises
INCF Cycles,F ;Increase the number of cycles
MOVF Cycles,W ;File 0E to W
MOVWF Counter1 ;W to file 10h
DECFSZ Steps,F
Goto Repeat
GOTO Siren
END
I'm a beginner in electronics & PICs even new to this Forum.
I've compiled this coding & wondering someone can point me how can I calculate the required frequency & timing for this project using internal 4MHz oscillator
I need the sound to be raise from 500Hz to 1200Hz & falling again to 500Hz repeat forever.
change the constant value it changed the tone & timing too. How I know what is the frequency that I'm playing & the timing that repeated?
;Project: Siren Sound
List P = 12F675
#include <p12F675.inc>
__CONFIG _CP_OFF & _PWRTE_ON & _WDT_OFF & _INTRC_OSC_NOCLKOUT & _MCLRE_ON & _BODEN_ON
#define OUT GPIO,0 ;port pin defined as the actual output
errorlevel -302
;VARIABLES
Cycles EQU 20H ;holds # of cycles
Steps EQU 21H ;holds # of steps
Freq EQU 22H ;holds frequency variable
Counter EQU 23H ;variable used as counter
Counter1 EQU 24H ;variable used as counter
;CONSTANTS
N_cycles EQU .5 ; number of cycles
N_steps EQU .25 ; number of steps
N_freq EQU .170 ; constant that determines frequency
;********************************************************************
ORG 0 ;This is the start of memory for the program.
Setup: CLRF GPIO ;all outputs are zeroed
MOVLW 07H ;GPIO2:0 are digital IO
MOVWF CMCON ;
BSF STATUS,RP0 ;Go to Bank 1
CLRF ANSEL ;all digital IO
CLRF TRISIO ;Make all port output
BCF STATUS,RP0 ;Go to Bank 0 - the program memory area.
Siren: MOVLW N_cycles ;Number of cycles for each tone
MOVWF Cycles ;
MOVWF Counter1 ;
MOVLW N_steps ;Number of steps
MOVWF Steps ;File 0F holds the number of steps
MOVLW N_freq ;Determines frequency
MOVWF Freq ;File 0C determines the frequency
Repeat: MOVF Freq,W ;File 0C is moved to W
MOVWF Counter ;W is moved to file 0D for decrementing
On: BSF OUT ;Length of HIGH time to Piezo
DECFSZ Counter,F
GOTO On
MOVWF Counter ;W is moved to file 0D again
Off: BCF OUT ;Length of LOW time to Piezo
DECFSZ Counter,F ;
GOTO Off
DECFSZ Counter1,F ;Number of cycles for each tone
GOTO Repeat ;Go to repeat
DECF Freq,F ;HIGH and LOW is shortened -tone rises
INCF Cycles,F ;Increase the number of cycles
MOVF Cycles,W ;File 0E to W
MOVWF Counter1 ;W to file 10h
DECFSZ Steps,F
Goto Repeat
GOTO Siren
END
