PWM_ADC_2.asm

; Created: 11/27/2022 1:42:02 PM
; Author : uvind
;
;we cant get a good idea about environment light intencity by ldr connected on infront of the car
;when environment light intencity is below normal value, it ON the light according to the environment 
;light intencity.then it look for forward ldr and if light intencity on that ldr is above some value, 
;it reduce headlight value by half of present value.

sbi DDRD,6 ;set as output 
cbi DDRC,0
cbi DDRC,1
ldi R20,0x96
ldi R21,0x00
ldi R22,0xDC

ldi R18,1<<COM0A1|1<<WGM01|1<<WGM00
out TCCR0A,R18
ldi R19,1<<CS00
out TCCR0B,R19

ldi R16,0<<REFS0|0<<REFS1  ;Dissable internal vref and select analog input channel
sts ADMUX,R16   
ldi R16,1<<ADEN|1<<ADPS2|1<<ADPS1|1<<ADPS0  ;enable ADC and set pre scaler to 128
sts ADCSRA,R16
envi:
	ori R16,1<<ADSC   ;start conversion
	sts ADCSRA,R16
wait1:
	lds R16,ADCSRA   ;waiting until conersion ends
	sbrc R16,ADSC   
	rjmp wait1  ;if ADSC bit is cleared,loop ends

lds R17,ADCL ;read ADCL
lds R18,ADCH ;read ADCH

cp R20,R17
BRMI frwd
out OCR0A,R21
rjmp envi

frwd:

ldi R16,0<<REFS0|0<<REFS1|1<<MUX0  ;Dissable internal vref and select analog input channel
sts ADMUX,R16   
ldi R16,1<<ADEN|1<<ADPS2|1<<ADPS1|1<<ADPS0  ;enable ADC and set pre scaler to 128
sts ADCSRA,R16

	ori R16,1<<ADSC   ;start conversion
	sts ADCSRA,R16
wait2:
	lds R16,ADCSRA   ;waiting until conersion ends
	sbrc R16,ADSC   
	rjmp wait2  ;if ADSC bit is cleared,loop ends

lds R23,ADCL ;read ADCL
lds R18,ADCH ;read ADCH 
cp R22,R23
BRMI decrs
out OCR0A,R17
rjmp envi

decrs:
out OCR0A,R20
rjmp envi