problem in serial communication with hardware of ATMEGA32...

[ismbn]

Hi all...

I am using ATmega32. I have done this coding

int main(void)
{

	uart_init(103);  // set 9600 baud rate
	DDRA=0xFF;
	DDRB=0xFF;
	DDRC=0xFF;

	while(1)
	{
		PORTA=PORTB=PORTC=0xFF;
		_delay_ms(100);
		PORTA=PORTB=PORTC=0x00;
		_delay_ms(100);
		print('A');  // send 'A' via usart
	}
}

and burned (using USBasp for burning)it with Fuse setting for external ceramic resonator...
LOW Fuse = 0xCE;
HIGH Fuse = 0xC9;
But i am getting the correct communication on 600 Baud rate not on 9600 Baud rate...
I not understanding where i am wrong... please help me...
I have checked the same hardware before 3-4 week, It was working fine....
Please Help Its Urgent

Ismail

 

[ismbn]

I am using serial Port communication via RS232..
On TXDpin i am getting 6.40V
And on RXD pin I am getting 7.79V

is there any problem with this

Ismail

 

[alexan_e]

What is the ceramic resonator frequency?
Did you previously use the same hardware with the same resonator?

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I hope you have connected a MAX232 between the PC and AVR

 

[ismbn]

thank you

What is the ceramic resonator frequency?

i have connected 16MHz crystal with 22pF cap...

Did you previously use the same hardware with the same resonator?

yes i have used it... this that kit only for which we have communicated in
https://www.edaboard.com/threads/265009/


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I hope you have connected a MAX232 between the PC and AVR

yes i have connected that MAX232... why Sir?

Ismail

 

[alexan_e]

You said that you measure 7v in the rx/tx pins and this is wrong , you mean the AVR pins right?

 

[ismbn]

You said that you measure 7v in the rx/tx pins and this is wrong , you mean the AVR pins right?

yes i have measured it.. but don't know that is it right or no?

yah this is the avr pin only

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will you believe me if i will tell you i am getting 8.09 V form USBasp.. which i am using to burn the Hex

ismail

 

[jjeevan007]

check whether MAX232 is working properly or not..........
or change MAX232 ic and see.........

 

[ismbn]

Hi jjeevan007..
Thanks for the reply...
But as i told i am getting 8V from the USB... and more i am getting the correct output at 600 baud rate, if i am setting it to 9600...
after this is there is need to change the MAX... what do you think... :roll:
Ismail

 

[jjeevan007]

i think the multimeter which you are using is not working properly, because u cant get USB voltage more than 5v,

so change the battery of multimeter and try to measure the voltage.........


jeevan

 

[ismbn]

yes i think you are right.... i doing that only

ismail

 

[jjeevan007]

tell me whats the core clock frequency................

 

[ismbn]

tell me whats the core clock frequency................

i am sorry which freq.??????

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i am sorry my meter was not working i am getting 5 V on txd/rxd pin...

Ismail

 

[nandhu015]

Post your schematic, Most probably the problem is with hardware.

The fuse setting for oscillator may be problem.

 

[jjeevan007]

try this.........

uart_init(47);

 

[ismbn]

Post your schematic, Most probably the problem is with hardware.

The fuse setting for oscillator may be problem.

Yes i also think the problem is with hardware only... because in simulation its working gr8.
this is a ready made kit... i have just this that i am attaching...

and the fuse bits are

Lower fuse = 0xCE;
Higher fuse =0xC9;

CKSEL0=1
CKSEL1=1
CKSEL2=1
CKSEL3=1

SUT0 = 1
SUT1 = 0

CKOPT =0

this setting is for
using external ceramic resonator.
frq. range is 1MHz and above full R/R swing in clk option
startup time = 0 ms additional delay after reset
Oscillator option= full R/R Swing


ismail

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try this.........

uart_init(47);

i made

uart_init(47);

still its giving the output on 600 bps only....

but how it is possible....

ismail

 

[ismbn]

Hay I have done it....it is working fine.... I am not sure but.. there is some problem in AVR studio 6 I think. I will put some screen shots tomorrow

 

[ismbn]

please see the images which cause the problem



Ismail