On Thu, Feb 28, 2002 at 03:12:55PM +0100, Peter Meleschko wrote:
> Hi,
>
> I'm trying to program a 16F872 using LVP and so far only failed.
> I have searched the net and read MC docs (eg. ds39025e) but clearly i'm
> missing something.
> I have been using a  VERY simple programmer Ludipipo style (whatever
> that means) with which I have programmed 16F84 lots of times. I thought
> that with some slight mods. this could be used to program the 87X.
>
> So far i have used PonyProg as PC programming sw.
> Can anybody direct me to schematics of a simple serial(PC) ICSP
> programmer or anything else that could help me going again.

Take a look at my Trivial LVP programmer here:

http://www.finitesite.com/d3jsys

I've gotten new reports of it working with David Tait's new FPP programming
software.

A couple of caveats if you have problems:

1) Keep the programming cable short. It's TTL, not RS-232. 2-3 meter parallel
port cables will probably give you fits.

2) You can experiment with the resistor value. Increasing it will give more
drive from the PIC back to the parallel port input.

It's simple. It's cheap. It can be build from $5 of RadioShack (RadioSpares?)
parts.

I also have a question. Does anyone know of a free parallel port monitor
for Windows. I'd like to point folks to an application where they can
set/reset parallel port output bits and view the incoming bits. I use
picprg2.3b programmer for Linux which has this functionality built into
the programmer configuration page. But since I don't do Windows on a regular
basis, and it doesn't seem that FPP or Nigel Goodwin's picprg877 has that
functionality, I'd like to be able to point folks to something that they can
test the TLVP programmer out with.

Over the last few weeks I had one gentleman who's testing strategy was to
fiddle with the board (sometimes dangerously by shorting outputs together)
and testing to see if it programmed. I'd like to give TLVP developers something
a bit more systematic to test with.

I hope that TLVP can be helpful even if only in a temporary capacity. As I
point out on my page, I developed it as a throwaway/temporary programmer so
that I can load bootloaders into 16F87X parts. I find that bootloaders are
generally more flexible than programmers, even ICSP ones.

BAJ

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