Help in PWM

[hero_o_2010]

I want to generate a PWM to make fade in or out ( by led ) with atmega 32

" in C language "

thanks

 

[c36041254]

Hi there, Welcome to electro-tech
I'm not using atmega ,never did and also not using C, I;m a PIC guy and use assembly language but, I recently made a code to control brightness of an LED connected at PORTC, pin 0 of 16f690, Let me put the code and that may help you to develop your own........

 	List p=16f690
	#include<p16f690.inc>
	__CONFIG _MCLRE_ON & _CP_OFF & _WDT_OFF & _INTRC_OSC_NOCLKOUT
	ERRORLEVEL-302
;***********************************************************************
	cblock 0x20
		temp
		d1
		d2
		dis
	endc
;************************************************************************
	org 0x0
	goto main
;************************************************************************
main:
portset:
	bsf STATUS,RP0		;all output
	clrf TRISA
	clrf TRISB
	clrf TRISC
	bcf STATUS,RP0
PWMset:
	movlw b'00000001'
	movwf PORTC
	call bright1		;call delay for that much time LED to be bright
	movlw b'00000000'
	movwf PORTC
	call bright2		; call delay for an LED to remain off
	goto PWMset
bright1:
	movlw d'200'		; select on time delay
	movwf d1
delayon:
	decfsz d1
	goto delayon
	return
bright2:
	movlw d'56'			;select off time delay
	movwf d2
delayoff:
	decfsz d2
	goto delayoff
	return
	end

note that total of on and off delay should be 256 for an 8 bit processor.