gnupic: DIY USB programmer ?
Subject:
Re: DIY USB programmer ?
From:
Manuel Bessler ####@####.####
Date:
7 Jan 2005 16:49:13 +0000
Message-Id: <20050107174556.B1120@betazed3.varxec.de>
On Thu, Jan 06, 2005 at 04:44:27PM -0500, Byron A Jeff wrote:
> > Thats why I said that I already have that. Olimex has a schematic after
> > which I did the layout. And I checked if those pin assignments are
> > half-way sane, and I believe they are (maybe not for a production
> > programmer, but ok for a prototype programmer).
>
> You missed my point. Your user will still have to solder the sockets. ICSP
> keeps it simple.
Soldering is no problem. My users are "Home Cockpit *Builders*'... they
like to build. Some don't even fly as they have so much fun building :)
And as I said before, not all my boards have ICSP capability. (I didn't
want to figure out all the issues with isolating the ICSP pins from the
rest of the circuit.
An idea would be to build a purely ICSP programmer, and then offer a
small pcb layout for IC sockets. This socket-board could then just
plug into the ICSP header on the programmer.
> > So, what about requiring a 9..15V power supply, a 555 charge pump for
> > upping the power to 15V, then a 7812 and 7805. That makes sure that
> > sufficient power is available.
>
> Better to just require a 12-20V supply and regulate it down.
That'd be fine too.
> I see I'm going to have to keep you on point. It's only going to be used
Yes I know. I keep "straying" from my original ideas.
While I need a simple programmer for my users, a more complete programmer
for frequent use (for me and advanced users) is something that I'd personally
like to have for my own development work.
Like a half-intelligent USB 18F2550 based one proposed here.
Maybe we should split the ideas into
1. USB, cheap, simple, non-intelligent, few compontents ICSP programmer
and
2. USB, still cheap, (half-)intelligent, PIC-based development programmer
(maybe even with more than one voltage, isn't that what makes a
programmer a 'production programmer' ?)
> a handful of times. Keep it as simple as possible. A 12V wall wart will work
> for any flash PIC. Don't complicate it. 7805 and the 12V zener should be
> fine.
> > Another homecockpit interface solution (not opensource, and
> > Win+MS FlightSim only) uses something like that. See here:
> > http://fsbus.de/img/FSCOM.GIF
> > This solution has the advantage that the PIC burning is built-in.
> > The user just has to jumper the to-be-burned board to 'program mode'.
> > Of course he has to write the programming algorithms into his flightsim
> > interface software. The hexfiles are also compiled into that program.
>
> However his solution uses the modem control signals. I think you may find
> failures using a USB to serial cable depending on the USB chipset.
Well, maybe, I don't have experience with these cables.
Manuel
PS: Keep those ideas coming. This topic seems to be something that a lot
of folks are interested in.
--
Opensource/Free Software: No Gates, No Windows
