[En-Nut-Discussion] Problem connecting analog sound on port F

Vincent Timmerman vincenttimmerman at gmail.com
Thu Mar 13 13:23:17 CET 2008


I don't use JTAG for anything, so I disabled the JTAG fuse (set to 1).
My problem is now partially solved. But when I connect the audiosignal to
portf, it still gets very noisy. Already a bit less, but still too much. Is
there maybe a wrong connection made? I connected the output of the amplifier
circuit (check my first post) to the adc0 pin, and the ground of that board
to a ground pin on the analog expansion port.

I really want the noise gone, what can I try?

Vincent

On Thu, Mar 13, 2008 at 3:10 AM, Henrik Maier <hmlists at focus-sw.com> wrote:

> If you have a device which can only be programmed with JTAG then you must
> not touch the JTAG fuse bit as it renders the device not being
> programmable
> afterwards. You turned off the programming feature forever. This is not
> desirable in most situations.
>
> If your device is programmed using SPI/ISP, then the JTAG can be disabled
> safely using the fuse bit.
>
> More info can be found in the ATMega128 data sheet which I recommend to
> consult always before changing any fuse bits. It always a good idea to
> learn
> about the consequences of sometimes irreversible actions.
>
> Henrik
> http://www.proconx.com
>
> > -----Original Message-----
> > From: en-nut-discussion-bounces at egnite.de [mailto:en-nut-discussion-
> > bounces at egnite.de] On Behalf Of jakub nowak
> > Sent: Wednesday, 12 March 2008 11:00 PM
> > To: Ethernut User Chat (English)
> > Subject: Re: [En-Nut-Discussion] Problem connecting analog sound on port
> F
> >
> > For me there is no difference to change a fuse bit or registry. I
> > don't have any JTAG, I don't use debug, I want to use atmega128 as
> > atmega128 I don't need compatibility with atmega103. I know that if
> > You have JTAG better will be to change this by software but try by
> > hardware(manualy fusebits). I think that only risk changing fuse bits
> > is when You program with JTAG and You will turn him off or when You
> > change to wrong values fuses connected with oscilator.
> >
> > 2008/3/12, Vincent Timmerman <vincenttimmerman at gmail.com>:
> > > I tried it out with a disabled JTAG fuse, and it works. There is still
> > much
> > >  noise on my audio, but at least i hear it. I'll check the noise
> > reduction
> > >  first to see if there's room for improvement.
> > >
> > >  Thanks for the tip!
> > >
> > >
> > >  Vincent
> > >
>
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>



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