AVR Freaks

.include  "m48def.inc"

.def	Temp	=r16
.def	Temp1	=r17
.def	Delay	=r18
.def	Delay2	=r19

.equ	xclk	=PD6			;OC0A pin
.org	$000
	rjmp	RESET

RESET:							;Setup Stack
	ldi		Temp,high(RAMEND)
	out		SPL,Temp
	ldi		Temp,low(RAMEND)
	out		SPL,Temp

REGINIT:
	ldi		Temp,0b01000000		;setup PD6 as out
	out		DDRD,Temp
ADCINIT:						;setup	ADC
	ldi		TEMP,0b00000000
	sts		ADMUX,Temp
	ldi		Temp,0b11101111
	sts		ADCSRA,Temp

START:
	rcall 	RS232INIT
	rcall 	MESSAGE
	rcall	CTCSET 				;start up with ctc
;	rcall	PWMSET				;uncomment for different
;	rcall	PCPWMSET			;startup	
LOOP:
	rcall	dly
	rcall	RS232in				;get keypress from terminal

	cpi		Temp,'m'			;if m then send message
	brne	LPBY1
	rcall 	MESSAGE
	rjmp	LOOP
LPBY1:							;if a then read adc
	cpi		Temp,'a'
	brne	LPBY2
	rcall	ADCREAD
	rjmp	LOOP
LPBY2:							;if i then increment OCR0A
	cpi		Temp,'i'
	brne	LPBY3
	rcall	INCR1
	rjmp	LOOP
LPBY3:							;if d then decrement OCR0A
	cpi		Temp,'d'
	brne	LPBY4
	rcall	DECR1
	rjmp	LOOP
LPBY4:							;if f then set fast PWM
	cpi		Temp,'f'
	brne	LPBY5
	rcall 	PWMSET
	rjmp	LOOP

LPBY5:
	cpi		Temp,'t'			;if t then set ctc mode
	brne	LPBY6
	rcall 	CTCSET
	rjmp	LOOP

LPBY6:
	cpi		Temp,'p' 			;if p then phase correct 
	brne	LPBY7
	rcall	PCPWMSET
	rjmp	LOOP

LPBY7:
	cpi		Temp,'s'			;if s then set WGM02 bit
	brne	LPBY8
	rcall 	SETWGM02
	rjmp	LOOP
	
LPBY8:
	cpi		Temp,'c'			;if c then clear WGM02 bit
	brne	LPBY9
	rcall	CLRWGM02
	rjmp	LOOP

LPBY9:
tby1:							;print back to terminal

	rcall 	RS232OUT

	rjmp 	LOOP


RS232INIT:				;setup for 9600 baud at 14.7456 MHz
	ldi		Temp1,0
	ldi		Temp,95
	sts		UBRR0H,Temp1
	sts 	UBRR0L,Temp
	ldi		Temp, (1<<RXEN0)| (1<<TXEN0)
	sts		UCSR0B,Temp
	ldi		Temp, (1<<USBS0) | (3<<UCSZ00)
	sts		UCSR0C,Temp
	ret
							;
RS232in:					;Must use Regs - No sbis
	lds	    Temp,UCSR0A     ;Check Flag
	sbrs	Temp,RXC0
	rjmp 	RS232in
	lds		Temp,UDR0	    ;Load Data
	ret

RS232OUT:					;Must use Regs - No sbis

	lds		TEMP1,UCSR0A 	;Check Flag
	sbrs	TEMP1,UDRE0
	rjmp 	RS232OUT
	sts		UDR0,Temp		;Send Data
	ret
INCR1:						;this increments OCR0A
	in		Temp,OCR0A
	dec 	Temp
	out		OCR0A,Temp
;	rcall 	RS232OUT		;display to terminal
	ret

DECR1:						;this decrements OCR0A
	in		Temp,OCR0A
	inc 	Temp
	out		OCR0A,Temp
;	rcall 	RS232OUT		;display to terminal
	ret


ADCREAD:						;this code from avrfreaks 
								;beginners area for reading 
								;adc and formatting to 8bits
	lds		Temp,ADCL
	lds		Temp1,ADCH
	lsr		Temp1
	ror		Temp
	lsr		Temp1
	ror		Temp
	out		OCR0A,Temp		;update OCR0A 
	rcall	RS232OUT		;send out to terminal
	ret

PWMSET:						;this sets up fast pwm on OC0A
							;clock /1024
							;clear OC0A on match
							;mode 3 top is 0xFF but
							;OCR0A seems to vary it
							;setting WGM02 bit turns on
							;mode 7- but no output is seen

	ldi		Temp,(1<<COM0A1)|(1<<WGM00)|(1<<WGM01)
	out		TCCR0A,Temp
	ldi		Temp,(1<<CS00)|(1<<CS02)
	out		TCCR0B,Temp
	ldi		Temp,156
	out		OCR0A,Temp
	ret


CTCSET:					;setup timer0 for CTC mode
						;clock/1024
						;toggle OC0A
						;WGM02 seems to have no difference

	ldi		Temp,(1<<COM0A0)|(1<<WGM01)
	out		TCCR0A,Temp
	ldi		Temp,(1<<CS00)|(1<<CS02)
	out		TCCR0B,Temp
	ldi		Temp,128		;set ocr0a at midpoint
	out		OCR0A,Temp
	ret

PCPWMSET:				;setup timer for phase correct pwm
						;clock/1024
						;clear	OC0A on match
						;mode 1 top should be 0xFF
						;but OCRA  seems to 
						;have an effect
						;setting WGM02 makes mode 5

	ldi		Temp,(1<<COM0A1)|(1<<WGM00)
	out 	TCCR0A,Temp
	ldi		Temp,(1<<CS00)|(1<<CS02)
	out		TCCR0B,Temp
	ldi		Temp,128
	out		OCR0A,Temp
	ret

SETWGM02:
	in		Temp,TCCR0B
	sbr		Temp,1<<WGM02
	out 	TCCR0B,Temp
	ret

CLRWGM02:
	in		Temp,TCCR0B
	cbr		Temp,1<<WGM02
	out 	TCCR0B,Temp
	ret

STEPTEST: 				;send out 200 clocks to stepper
	ldi		Temp,200
STPINDX:
	sbi		PORTB,xclk	;clock active high
	ldi		Temp1,200
STPBY1:
	dec		Temp1		;hold line high for awhile
	brne	STPBY1
	cbi		PORTB,xclk
	rcall 	dly1
	dec		Temp
	brne	STPINDX
	ret

DLY:						;just a delay 

	dec		Delay
	brne	DLY
	dec		Delay2
	brne	DLY
	ret
DLY1:
	ldi		Delay2,45
	
DLY1A:
	ldi		Delay,250
DLY1B:
	dec		Delay
	brne	DLY1B
	dec		Delay2
	brne	DLY1A
	ret

MESSAGE:
	ldi 	ZL,low(2*msg)
	ldi 	ZH,high(2*msg)
Strout:
	lpm		Temp,Z+
	tst		Temp
	breq 	sext
	rcall 	rs232out
	rjmp 	Strout
SEXT:
	ret

MSG:

	.db "Hello World here I am " ,10,13
	.db "This is just a test of ny typing  skills ",10,13,0