gnupic: DIY USB programmer ?
Subject:
Re: DIY USB programmer ?
From:
Byron A Jeff ####@####.####
Date:
13 Jan 2005 13:50:18 +0000
Message-Id: <20050113135014.GC3300@cleon.cc.gatech.edu>
A list management question before I get started. Does anyone know if it's
possible to get the list to set the Reply-To field in the mail header?
I've noticed that my replies go back to the author with the list being CCed
instead of just going to the list. Since we are all on the list, there's
really no need to be sending extra copies.
On Wed, Jan 12, 2005 at 02:47:09PM -0500, David Willmore wrote:
> > > Now, the only question/decision is to decide if we want to make this
> > > design to be a 'bootstrap whatever PIC' or 'bootstrap *a* PIC to make
> > > a *real* programmer for *your* PIC'. The software is a lot easier
> > > for the latter, but the hardware is a little bit more complex--you
> > > need a design that is both a bootstrap programmer and a real programmer.
> >
> > For the latter, you mean that it should be a programmer that
> > * has the ability to 'bootstrap itself', ie. program the PIC for the
> > intelligent part of the programmer using a non-intelligent "do it
> > once" approach like what Byron is working on.
> > * once bootstrapped can be used as a USB based general purpose hobby
> > PIC programmer (maybe even as a production programmer if its not too
> > much extra work)
>
> Exactly. The 556 can be used in two places in the circuit--once for the
> bootstrapper and once in a HV power supply switcher. That keeps the
> micro from having to walk, chew gum, pat its head and rub its belly all
> at once. ;)
You'll have to change up some parts to get it going as I'm sure that the
frequency for the HV will have to be higher than the delays for the
monostables.
>
> > > For my part, I'm willing to make my code for a USB/RS-232 based semi-
> > > intelligent programmer available. The 18F2550 should be available
> > > for a few years and we'll see about porting it to whatever successor
> > > it has when/if it goes away.
> >
> > I have a AN851 variant bootloader and Linux code for it. (A windows port
> > is in progress.)
> > As I'm currently working on that as part of my project, the code is
> > maintained and could be used for the programmer if wanted.
>
> A simple bootstrap programmer would be great. Once Byron comes up with
> a final hardware design, I'll look into adding support for it to Pikdev--
> I'll have to look into how to add a new backend so that the programmer
> can be used in 'semi-intelligent' mode.
I took a 5 minute look at Pikdev. It'll require adding a new type of programmer
separate from the parallel and serial programmers defined now. Fortunately
the class only has a handful of definitions. I didn't see how to connect the
type to the class though. It should be too difficult to pull off.
I think I'm going to adopt pikdev for my programmers since it has 18F support
and works with the Trivial programmers.
>
> > > I'd like to see a design that will last a few years--maybe until the
> > > time that USB phases out. :)
> >
> > Sounds good to me :)
>
> :) Well, for my part, I'm going to try to finish up some Pikdev chip
> support code (sorry Alain) and watch Byron work his magic! :)
I hope to get a chance to work on it some more between now and the weekend.
I'm continuing to think on the verify problem that I outlined in my
preliminary results post. I realize that I need to isolate the PIC Program
Data pin from both the incoming TX circuit (which I was going to do anyway)
and the outgoing RX circuit. So it'll take a couple more transistors.
I'm starting to think that a modular design may be possible without too
much effort. That way you can build the design with or without verification.
BAJ
