; --- Piano2.asm ----
; When you press button RB0..RB3, you play a note
; on RC0:
;   RB0:  291 Hz (C4)
;   RB1:  293 Hz (D4)
;   RB2:  329 Hz (E4)
;   RB3:  349 Hz (F4)

#include <p18f4620.inc>

; Variables
CNT0 EQU 1
CNT1 EQU 2

; Program
	org 0x800
	call Init
Loop:
        movlw 0
        cpfseq PORTB	; if any button is pressed
	btg   PORTC,0
	
	btfsc PORTB,0
    call  C4
	btfsc PORTB,1
    call  D4
	btfsc PORTB,2
	call  E4
	btfsc PORTB,3
	call  F4
	
	goto Loop

; --- Subroutines ---

Init:
	clrf TRISA  	;PORTA is output
    movlw 0xFF
	movwf TRISB 	;PORTB is input
	clrf TRISC 		;PORTC is output
	clrf TRISD 		;PORTD is output
	clrf TRISE 		;PORTE is output
	movlw 15
	movwf ADCON1 	;everyone is binary
	return

C4:   ; 261Hz = 19,157 clocks
	movlw 19
	movwf CNT1
C4a:
	movlw 100
	movwf CNT0
C4b: 
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	decfsz CNT0, F
	goto C4b
	decfsz CNT1, F
	goto C4a
	return

D4:   ; 293.66Hz = 17,026 clocks
	movlw 17
	movwf CNT1
D4a:
	movlw 100
	movwf CNT0
D4b: 
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	decfsz CNT0, F
	goto D4b
	decfsz CNT1, F
	goto D4a
	return

E4:   ; 329.63Hz = 15,167 clocks
	movlw 15
	movwf CNT1
E4a:
	movlw 100
	movwf CNT0
E4b: 
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	decfsz CNT0, F
	goto E4b
	decfsz CNT1, F
	goto E4a
	return

F4:   ; 349.23Hz = 14,317 clocks
	movlw 14
	movwf CNT1
F4a:
	movlw 100
	movwf CNT0
F4b: 
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	decfsz CNT0, F
	goto F4b
	decfsz CNT1, F
	goto F4a
	return


	end