Salah wrote:

>Hello List,
>  Anybody knows where to find some Vbasic code about how to read the RS-232
>data from the PC serial port which is connected to PIC MPU sending data in
>continous way. Any links,ideas are all welcomed.
>Regards,
>Salah.

   Hi, Salah.
   Didn't you see, all PICList heavy-weights dislike M$ software?
You mean MS VB, yeah? Most of the community are extremely
software-ascetic, being EE. Have look at postings in threads:
   "Best small windows developer platform??"
   "You Can Make it if You Try, Roman."
   Personally, I can't afford myself to be a software spartan,
since I have to make my living in any way, so what can I say:
   You are on a right way, Salah. MS VB is a good choice, sure.
As for me, the best way to handle RS-232 from VB is using
MS Comm control.
   Going this way, you absolutely need MSDN, installed on
your computer, particularly "VBREF98.CHM" book. In the chapter
"Controls reference"-"ActiveX controls" it has a lot of documentation
on "MSComm Control" with examples.
   To handle RS-232 from PIC side, if you going to start with 16F87X,
you may read:  "PICmicro MID-RANGE MCU FAMILY", DS31018A,
Section 18. USART
   In addition I'd like to mention Olin Lathrop's posting "Re: [EE]: Class AB
output stage clipping". It goes about electronics, but the idea how to choose
learning curve is the same.

>If the purpose is to learn something about electronics, then doing a project
>like this is a good idea.  However, you have to take it one step at a time.
>Stop trying to get an overall result and instead focus on undertanding every
>piece of this circuit, one stage at a time.  You will also need to learn
>more about electronics and amplifiers as you go along.  Nobody here has time
>to walk you thru a couple semesters of electronics theory, so you need to
>find a book, take a course, or whatever on your own.  In particular you seem
>to be missing the whole concept of feedback.  We can help with specific
>questions, but you have to understand enough of the theory first to make
>sense of the answer.
>The circuit you attached of the new final stage makes a lot more sense than
>the previous one.  I suggest you start with it by driving it from an opamp
>and watching the various waveforms on a scope.  Then take out the diodes and
>see what happens.  Can you partially correct for this effect using feedback?
>Is it oscillating now?  If so, why?  How do you stop it?

   Great thoughts, by the way.
      Why not to strike them on a PICList  facade wall?

   Good luck.
   Mike.

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