AVR-Chat

Hello,




  I looked at the code and I couldn't find anything wrong.  Situations 
like these are why I bought an ICE200 emulator.  It becomes easy to 
try lots of little variations in order to find what the one little 
thing is that is preventing success.




  Anyway, I reformatted the code to make it a little more readable.  
Maybe the different format will be interesting as an alternative to 
'magic numbers'.




  I would be interested in finding out why this doesn't work.




Alan Probandt


Portland, OR




****** code below***




.def 	temp = r16 ;define register 16 as TEMP


.def 	ADCRESULT = r17 ;define register 17 to hold ADC value


.equ 	volt1 = 0x33 ;1 volt threshold value(51 bits/volt)


.equ 	volt2 = 0x66 ;2 volt threshold value


.equ 	volt3 = 0x99 ;3 volt threshold value


.equ 	volt4 = 0xCC ;4 volt threshold value


.equ 	volt5 = 0xFF ;5 volt threshold value      


.equ	LED5v = 4 ; PortB 4  


.equ	LED4v = 3 ; PortB 3  


.equ	LED3v = 2 ; PortB 2  


.equ	LED2v = 1 ; PortB 1  


.equ	LED1v = 0 ; PortB 0  


.equ	LEDon = 0


.equ	LEDoff = 1




.org 0x0000


	rjmp 	RESET ;jump to reset over vector space






RESET:


	ldi 	temp, 0b00011111 ;Value to set port B pins 0,1,2,3,4


	out 	DDRB, temp ;to be outputs, 5 to be ADC input


	    	


	ldi 	temp, 0b00011111 ;value to turn LEDs on port B pins 0-4 
off. 


	out 	PORTB, temp ;load value to port B


	    	


	ldi 	temp, (1 << ADLAR) | (0<<MUX2) | (0<<MUX1) | (0<<MUX0) 
;0b00100000 ;0x20 ;Value to set ADC to: Vcc reference,


	out 	ADMUX, temp ;left adjust result,input to PB5 (AD0)


	    	


	ldi 	temp, (1 << ADEN) | (1 << ADPS1) | (1<< ADPS0); 
0b10000011 ; 0x83 ;Value to set up ADC: set to single mode,


	out 	ADCSR, temp ;enable ADC, set ADC prescaler to clk/8, 
disable ADC interrupt


	


	ldi 	temp, (1 << PUD) ;0x40 ;value to set the PUD bit in the 
MCUCR to disable


	out 	MCUCR, temp ;pullup resistors on i/o pins, and load it 
to MCUCR


	    	


	    	


	rjmp	MAIN ;jump to main program


	


	


MAIN:	sbi 	ADCSR, ADSC ;set flag to start AD conversion  sbi 
0-31, 0-7




LOOP:	sbis 	ADCSR, ADIF ;test if conversion is done. if done


;skip next line and continue, else loop


;back and test again




	rjmp 	LOOP ;repeat until conversion is done




	cbi 	ADCSR,ADIF ;clear "conversion complete" flag




	in 	ADCRESULT, ADCH ;load ADC result to register






	ldi 	temp, (LEDoff << LED5v) | (LEDoff << LED4v) | (LEDoff << 
LED3v) | (LEDoff << LED2v) | (LEDoff << LED1v) ; 0x1F ;value to turn 
LEDs off (on port B pins 0-4).


	out 	PORTB, temp ;load value to port B


	


	


	cpi 	ADCRESULT, volt5 ;check if ADC reading is 5 volt or more


	brsh 	VOUT5 ;if 5 volts or greater, jump to subroutine to


	;turn on LEDs on port B, pins 0-4


	


	cpi 	ADCRESULT, volt4 ;check if 4 volts or more, if so, turn 
on LED


	brsh 	VOUT4 ;port B pins 0-3






	cpi 	ADCRESULT, volt3 ;check if 3 volts or more, if so, turn 
on LED


	brsh 	VOUT3 ;on port B pins 0-2


	


	


	cpi 	ADCRESULT, volt2 ;check if 2 volts or greater, if so, 
turn on LED


	brsh 	VOUT2 ;on port B pins 0-1


	


	


	cpi 	ADCRESULT, volt1 ;check if 1 volt or greater, if so, 
turn on LED


	brsh 	VOUT1 ;on port B pin 0


	


	


	ldi 	temp,(LEDoff << LED5v) | (LEDoff << LED4v) | (LEDoff << 
LED3v) | (LEDoff << LED2v) | (LEDoff << LED1v) ;0x1F ;all above tests 
are false, turn off all LEDS


	


	rjmp 	MAIN ;return for another sample


	


	


	


	VOUT5:


	ldi 	temp, (LEDon << LED5v) | (LEDon << LED4v) | (LEDon << 
LED3v) | (LEDon << LED2v) | (LEDon << LED1v) ;0x00 ;value to turn on 
all LEDs


	out 	PORTB, temp ;turn on LEDs


	rjmp 	MAIN ;return for another sample


	


	VOUT4:


	ldi 	temp, (LEDoff << LED5v) | (LEDon << LED4v) | (LEDon << 
LED3v) | (LEDon << LED2v) | (LEDon << LED1v) ;0x10 ;value to turn on 
LEDs on port B 0-3


	out 	PORTB, temp ;turn on LEDs


	rjmp	 MAIN ;return for another sample


	


	VOUT3:


	ldi 	temp,(LEDoff << LED5v) | (LEDoff << LED4v) | (LEDon << 
LED3v) | (LEDon << LED2v) | (LEDon << LED1v) ; 0x18 ;value to turn on 
LEDs on port B 0-2


	out 	PORTB, temp ;turn on LEDs


	rjmp	 MAIN ;return for another sample


	


	VOUT2:


	ldi 	temp, (LEDoff << LED5v) | (LEDoff << LED4v) | (LEDoff << 
LED3v) | (LEDon << LED2v) | (LEDon << LED1v) ; 0x1C ;value to turn on 
LEDs on port B 0-1


	out 	PORTB, temp ;turn on LEDs


	rjmp	 MAIN ;return for another sample


	


	VOUT1:


	ldi 	temp, (LEDoff << LED5v) | (LEDoff << LED4v) | (LEDoff << 
LED3v) | (LEDoff << LED2v) | (LEDon << LED1v) ;0x1E ;value to turn on 
LEDs on port B 0


	out 	PORTB, temp ;turn on LEDs


	rjmp	 MAIN ;return for another sample