AVR-Chat

I am sending out data thru the UART of a ATmega 165p  to hyperterminal. The data looks fine when I debug using the JTAG debugger but when I program the chip for stand alone operation. I can't get any output. I made sure that the clock is what it should be and the baudrate aswell. Can someone help me figure out what could cause this problem. 

Thank you for your help


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On Jan 14, 2008 8:49 PM, Levar Man <micro_chipman@yahoo.com> wrote:
> I am sending out data thru the UART of a ATmega 165p  to hyperterminal. The data looks fine when I debug using the JTAG debugger but when I program the chip for stand alone operation. I can't get any output. I made sure that the clock is what it should be and the baudrate aswell. Can someone help me figure out what could cause this problem.

Is there a ground connection between the PC and the system when the
debugger isn't plugged in?

It might be a good idea to give some info on what crystal frequency you're 
using, what values you've initiated the UART registers with, and the 
parameters of the UART you want to use (e.g. 9600 N 8 1, etc.)

Do you have hyperterminal set up for the same parameters?

Zack

On Mon, 14 Jan 2008, Levar Man wrote:

> I am sending out data thru the UART of a ATmega 165p  to hyperterminal. The data looks fine when I debug using the JTAG debugger but when I program the chip for stand alone operation. I can't get any output. I made sure that the clock is what it should be and the baudrate aswell. Can someone help me figure out what could cause this problem.
>
> Thank you for your help
>

--- In AVR-Chat@yahoogroups.com, "David VanHorn" <microbrix@...> wrote:
>
> On Jan 14, 2008 8:49 PM, Levar Man <micro_chipman@...> wrote:
> > I am sending out data thru the UART of a ATmega 165p  to 
hyperterminal. The data looks fine when I debug using the JTAG debugger 
but when I program the chip for stand alone operation. I can't get any 
output. I made sure that the clock is what it should be and the 
baudrate aswell. Can someone help me figure out what could cause this 
problem.
> 
> Is there a ground connection between the PC and the system when the
> debugger isn't plugged in?
>
Yes it should be grounded.

> > Is there a ground connection between the PC and the system when the
> > debugger isn't plugged in?
> >
> Yes it should be grounded.


I agree that it SHOULD be, but the question was wether it IS.

In theory, there is no difference between theory and practice. :)

To Clarify -

Bidirectional RS232 requires at least 3 connections - Rx,  Tx, and  
Common or Ground. If your cable has no ground wire, it could have  
worked through the JTAG ground. Removing JTAG would then cause the  
RS232 to fail. Check your cable with an ohm meter or continuity  
checker to verify that (pin 5, I think, on DB29 cables).

Jim

On Jan 15, 2008, at 9:14 AM, David VanHorn wrote:

> > > Is there a ground connection between the PC and the system when  
> the
> > > debugger isn't plugged in?
> > >
> > Yes it should be grounded.
>
> I agree that it SHOULD be, but the question was wether it IS.
>
> In theory, there is no difference between theory and practice. :)
>
> 



[Non-text portions of this message have been removed]

That should have read DB9 cables.

Jim

On Jan 15, 2008, at 9:30 AM, James Wagner wrote:

> To Clarify -
>
> Bidirectional RS232 requires at least 3 connections - Rx, Tx, and
> Common or Ground. If your cable has no ground wire, it could have
> worked through the JTAG ground. Removing JTAG would then cause the
> RS232 to fail. Check your cable with an ohm meter or continuity
> checker to verify that (pin 5, I think, on DB29 cables).
>
> Jim
>
> On Jan 15, 2008, at 9:14 AM, David VanHorn wrote:
>
> > > > Is there a ground connection between the PC and the system when
> > the
> > > > debugger isn't plugged in?
> > > >
> > > Yes it should be grounded.
> >
> > I agree that it SHOULD be, but the question was wether it IS.
> >
> > In theory, there is no difference between theory and practice. :)
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
> 



[Non-text portions of this message have been removed]

Thanks Jim, I will check the ground connection and see if this could 
be the problem. Again Thanks

--- In AVR-Chat@yahoogroups.com, James Wagner <wagnerj@...> wrote:
>
> That should have read DB9 cables.
> 
> Jim
> 
> On Jan 15, 2008, at 9:30 AM, James Wagner wrote:
> 
> > To Clarify -
> >
> > Bidirectional RS232 requires at least 3 connections - Rx, Tx, and
> > Common or Ground. If your cable has no ground wire, it could have
> > worked through the JTAG ground. Removing JTAG would then cause the
> > RS232 to fail. Check your cable with an ohm meter or continuity
> > checker to verify that (pin 5, I think, on DB29 cables).
> >
> > Jim
> >
> > On Jan 15, 2008, at 9:14 AM, David VanHorn wrote:
> >
> > > > > Is there a ground connection between the PC and the system 
when
> > > the
> > > > > debugger isn't plugged in?
> > > > >
> > > > Yes it should be grounded.
> > >
> > > I agree that it SHOULD be, but the question was wether it IS.
> > >
> > > In theory, there is no difference between theory and 
practice. :)

> > >
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> > 
> 
> 
> 
> [Non-text portions of this message have been removed]
>