[Ghulam Mustafa]

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[Ghulam Mustafa]

Hello,

I have found this program and is working wel for AVR ATmega16 for ADC conversion and wanted to share

 

I found it in Avr Microcontroller’s Book by Mazidi

.INCLUDE “M16DEF.INC”

LDI R16,0xFF

OUT DDRB,R16

OUT DDRD,R16

LDI R16,0

OUT DDRA, R16

LDI R16,0x87

OUT ADCSRA,R16

LDI R16,0xC0

OUT ADMUX, R16

 

READ_ADC:

SBI ADCSRA,ADSC

KEEP_POLING:

SBIS ADCSRA,ADIF

RJMP KEEP_POLING

SBI ADCSRA,ADIF

IN R16,ADCL

OUT PORTB,R16

IN R16,ADCH

OUT PORTD,R16

RJMP READ_ADC

 

[Ghulam Mustafa]

An important observation:

When the input voltages are less than 2V this error doesnt occour!

[Ghulam Mustafa]

i think that the coder has send all the 10 bits to port b this is the reason that the port is flashing. What do you ppl think?

[Ghulam Mustafa]

I have added 4Mhz crystal now, but still facing the same error.

I have tried some other program which is running correctly.

So the problem, i think is in the code. http://www.engineersgarage.com/embedded/avr-microcontroller-projects/adc-circuit

Kindly check it and inform me, why the ports are continously blinking.

Thanks

[Ghulam Mustafa]

Thanks very much

Two thinks to ask before implementing.

1- this program was simulated on Proteus and was running well without the oscillator

2- Is there any prblem in the fuse bits

Pls reply so that i may implement it now

[Ghulam Mustafa]

Hello Amrith

Thanks for replying, i have mentioned the link which i am following to develop the circuit. Actually i doesnt contain any external oscillator.

Thanks

[Ghulam Mustafa]

wysiwyg_imageupload:5162:Hello,

I am using the following cofiguration for the atmega16 controller.

I think that the last reason may be this issue.

Kindly check and inform if this is the main issue.

Thanks

 

[Ghulam Mustafa]

I tried it all but the program is not running. Also when i simulated the circuit in Proteus it is working correctly, while not on the bread board.

Also another simple circuit has the same problem

Pls guide what migt be the problem and how it could be resolved.

Thanks

[Ghulam Mustafa]

Thanks alot,

I compiled and burn the program on the chip, i am facing a problem that the LED present at the output are continously blinking if i provide some voltage on the adc pin, otherwise if i connect this pin to VCC or GND, they are continously high or low.

Pls guide what could be the problem now.

Thanks again

[Ghulam Mustafa]

Thanks alot

I have programmed the AVR, http://www.engineersgarage.com/embedded/avr-microcontroller-projects/adc-circuit but LED’s are flashing continously, while when i switch them to Gnd all are Off, and when Vcc is supplied all are High.

While when connected to Pot, they flash with different values.

What might be the problem now?

[Author]

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