;
; AssemblerApplication1.asm
;
; Created: 2025-11-19 09:45:59
; Author : alvka474
;
; Replace with your application code

	ldi r16, HIGH(RAMEND)
	out SPH, r16
	ldi r16, LOW(RAMEND)
	out SPL, r16

	.equ T = 40

	call MORSE

;;;;;;;;;;;;;;;;;

NOBEEP: ; set r18 to 1 to signal no beep
	ldi r18, 1
	call BEEP
	ldi r18, 0
	ret
BEEP: ; beep i r16*T tidsenheter
	push r17
BEEP_OUTER:
	ldi r17, T
BEEP_INNER:
	cpi r18, 1 ; om r18 == 1
	breq SKIP_BEEP
	sbi PORTD, 7
SKIP_BEEP:
	call DELAY
	cbi PORTD, 7
	call DELAY
	dec r17
	brne BEEP_INNER
	dec r16
	brne BEEP_OUTER
	pop r17
	ret

;;;;,;;;;;;;;;;;;;;;

FANGA:
rjmp FANGA

;;;;;;;;;;;;;;;;;;;;;

GET_CHAR: ; get next ASCII char to r16
	lpm r16, Z+
	cpi r16, 0
	breq FANGA
	ret

;;;;;;;;;;;;

MORSE:
	call INIT
	call GET_CHAR
	call SEND_IT

;;;;;;;;;;;;;

SEND_IT:
	call ONE_CHAR
	rjmp SEND_IT


;;;;;;;;;;;;;;;;
ONE_CHAR:
	call BEEP_CHAR
	call GET_CHAR
	ret


;;;;;;;;;;;;;;;;;;;;;;;;;;;
BEEP_CHAR:
	call MELLANSLAG
	ldi r16, 2
	call NOBEEP

	breq END
	rjmp BEEP_CHAR
END:
	ret

;;;;;;;;;
BEEP_LETTER:
	call LOOKUP
	mov r20, r16
	call SEND
	ret

	
;;;;;;;;;;;

MELLANSLAG:
	cpi r16, $20
	breq JA ; vi har mellansla
	brne NO ; inte mellanslag

NO:
	rjmp BEEP_LETTER

JA:
	push r16
	ldi r16, 7
	call NOBEEP
	pop r16
	ret

;;;;;;;;;;;;;;;;;;;;;;;;;

SEND:
	call GET_BIT
	call SEND_BITS
	ret
	
;;;;;;;;;;;;;

SEND_BITS:
	call BIT
	brne SEND_BITS
	ret

;;;;;;;;;;;;;

BIT:
	ldi r16, 3
	brcs MAKE_LONG
	ldi r16, 1
MAKE_LONG:
	call BEEP
	ldi r16, 1
	call NOBEEP
	call GET_BIT
	ret
	
;;;;;;;;;;;;;;;;;;
GET_BIT: ; set flags for sending
	lsl r20
	ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;

DELAY: ; 1000 us
	push r18
	ldi r19, 10

DELAY_YTTRE:
	ldi r18,$1f
DELAY_INRE:
	dec r18
	brne DELAY_INRE
	dec r19
	brne DELAY_YTTRE
	pop r18
	ret
;;;;;;;;;;;;;;;;;;;;;;;;;;



;;;;;;;;;;;;;;;;;;;;;;;;

LOOKUP: ; r16 är ASCII returnera morse

	push ZH
	push ZL
	push r17

	ldi ZH, HIGH(MORSE_TABLE*2)
	ldi ZL, LOW(MORSE_TABLE*2)
	ldi r17, $41

	sub r16, r17; subtract A from ASCII to get indexing hex
	
	ADD ZL, r16
	ADC ZH, zero

	lpm r16, Z

	pop r17

	pop ZL
	pop ZH
	ret
;;;;;;;;;;;;;;



INIT:
	ldi r18, 0 ; set r18 to zero to allow beeping
	ldi ZH, HIGH(MESSAGE*2)
	ldi ZL, LOW(MESSAGE*2)
	.def zero = r2
	clr r2

INIT_HARDWARE:
	ldi r16, $ff
	out DDRD, r16
	ret

;;;;;;;;;;;;;;;

MESSAGE: .db "SOS", $00
MORSE_TABLE: .db $60,$88,$A8,$90,$40,$28,$D0,$08,$20,$78,$B0,$48,$E0,$A0,$F0,$68,$D8,$50,$10,$C0,$30,$18,$70,$98,$B8