-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
Roger Weichert
Sent: Thursday, August 13, 2009 9:35 AM
To: Microcontroller discussion list - Public.
Subject: Re: [PIC] Advise on replacing an obsolete micro with a PIC

Hi Jinx,

Thanks, I've been hoping it didn't sound like too unreasonable an idea.

While I dont have a huge amount of experience with PIC's, the few projects 
I've done have functioned well.

You are quite right with your comments about finding the original chip, and 
programming it ...  I had only provided the details because there were 
questions asked.

The only advantage may have been to find out the parameters for the reset 
and anything else that may have helped with understanding how it all worked.

The 'hardware questions' referred to the original post where I asked about 
the crystal eg.

I hadn't considered using the internal oscillator  ...  but after it was 
suggested I cant see why not  ... your thoughts? It's not like it needs to 
be super accurate  ...  we're just milking cows  :)

And also the supply. From the data sheets I see that 5.6 volts is too high.

I may just be showing my ignorance  ...  but if this other microcontroller 
has worked for 20 years with such a crude supply (5.6volt zener and a cap), 
is it possible that a 5 volt shunt regulator could be used  ..  (is there 
such a thing?) ... to keep it safe.

THERE ARE 5.1 volt zeners!

At present I only have two of these boards needing a new controller  ...  so

naturally I am hoping for a heap more to make it really worthwhile.


Hi Thomas,

You suggested a PIC18F1320  ...  any particular reason?

LIGHT, SWEET, in the 18F family, small number of pins, Cheap, Easy to use,
etc.


Thanks again guys,

Regards,   Roger





  *
  |  __O    Thomas C. Sefranek  WA1RHP@ARRL.NET
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