Chapter 8 . Garbled Screen Output on 'Echo', Yet ' Reset' Program Works Fine ?

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Abraxas

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Jul 29, 2011, 9:43:52 AM7/29/11
to PIC24 Assembly-to-C Book
I'm very sorry to be back so soon with yet another problem. I put the
Echo program on the pic and my led flashes. Nothing else works though.
When I click in the black box of RealTerm and type in a character and
hit enter, the character appears on the screen followed by what looks
like the Greek alphabet. My rxd and txd status boxes flash when I do
that.Nothing prints to screen when I do any sort of reset.
Interestingly, I skipped ahead and programmed the Reset program and it
quite nicely printed out the menu on the screen as indicated in the
text. As far as I can see then, that proves my wiring and setup is
fine. I've reloaded program a few times, same problem.

Abraxas

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Jul 29, 2011, 9:58:11 AM7/29/11
to PIC24 Assembly-to-C Book
Problem fixed as follows: The hex file I downloaded from the book
website was not functioning properly. When I downloaded the project
and compiled it, everything worked fine. Sorry for the bother.

Bryan A. Jones

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Jul 29, 2011, 10:03:08 AM7/29/11
to pic24-assemb...@googlegroups.com
Glad it's working!

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Robert Reese

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Jul 5, 2012, 8:53:21 AM7/5/12
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Hi,

So, if the reset messages work, then the  PIC24 TXD > PC RXD path works as you have stated.

If the increment and echo back of characters does not work, this would indicate to me that the PC TXD > PIC24 RXD path does not work and I would check that wiring.

You also need to check that the ground wire of the USB cable is connected to the ground of your breadboard -- if the USB cable and your breadboard  do not share a common ground this can cause a problem.

 Bob


On Wednesday, July 4, 2012 10:16:32 PM UTC-5, Charlie wrote:
I took quite a vacation from this and am back at it. Again, for some strange reason , the echo.hex on the internet site doesn't work but generates garbled code. When I download the c files and headers et al and build it myself, it almost works fine in that the reset reports are printed to the RealTerm( V 2.0.0.70), the increment and echo back of characters doesn't work. In fact when I type characters, they do not appear on the screen period, just flashing cursor squares. I was wondering if I had to hit another key after typing a character or I had it set up wrong. My TxD flashes when I type but there is no RxD flashes. Seem to recollect it working many months ago but I have since reinstalled the latest Realterm. Please keep in mind that the reset messages work fine, indicating no problem in the RxD path.


On Friday, 29 July 2011 10:03:08 UTC-4, Bryan A. Jones wrote:
Glad it's working!

On Fri, Jul 29, 2011 at 8:58 AM, Abraxas wrote:
Problem fixed as follows: The hex file I downloaded from the book
website was not functioning properly. When I downloaded the project
and compiled it, everything worked fine. Sorry for the bother.

On Jul 29, 9:43 am, Abraxas  wrote:
> I'm very sorry to be back so soon with yet another problem. I put the
> Echo program on the pic and my led flashes. Nothing else works though.
> When I click in the black box of RealTerm and type in a character and
> hit enter, the character appears on the screen followed by what looks
> like the Greek alphabet. My rxd and txd status boxes flash when I do
> that.Nothing prints to screen when I do any sort of reset.
> Interestingly, I skipped ahead and programmed the Reset program and it
> quite nicely printed out the menu on the screen as indicated in the
> text. As far as I can see then, that proves my wiring and setup is
> fine. I've reloaded program a few times, same problem.

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Robert Reese

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Jul 6, 2012, 10:40:07 AM7/6/12
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I am confused about what hex file you are talking about.  Is there a hex file for echo.c in the distribution?  If so, that should not be there. The only hex files that we try to include in the distribution is the hex code for the bootloaders -- all other applications such as chap8/echo.c, chap8/reset.c etc should be rebuilt by the user as users may change target baud rates, etc.

If a pre-built hex file for echo.c is giving garbled results, then it is probably because it was built with a different default baud rate.

And you are correct, our students always rebuild the hex files for applications.


On Thursday, July 5, 2012 8:43:26 PM UTC-5, Charlie wrote:
I don't know what the Seven Wonders of the World are but I do know what the 8th one is: turning your computer off and on. Works fine but only with my own built hex. Not the hex on the book website.
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