gnupic: Re: [gnupic] RE: [PIC] [gnupic] noob's 1st ques
Subject:
Re: [gnupic] RE: [PIC] [gnupic] noob's 1st ques
From:
Byron A Jeff ####@####.####
Date:
28 Jan 2006 18:36:32 +0000
Message-Id: <20060128183627.GA20601@cleon.cc.gatech.edu>
On Fri, Jan 27, 2006 at 02:33:20PM -0800, James Newton, Host wrote:
>
> > The real question in today's environment is what to do in the
> > face of the ever disappearing parallel port? My current
> > laptop doesn't have one. Serial ports are marginal from a
> > voltage standpoint and USB to Serial converters makes no
> > guarantees about modem control signals. It's fast getting to
> > the point where one needs a programmable part simply to
> > wiggle some pins.
>
> There is a nice long page of programmers available at
> http://www.piclist.com/techref/microchip/devprogs.htm that might help our
> O.P. find a programmer that works for him/her.
I need to get my Trivial Programmer on this list.
> But you raise an interesting question in my mind, regarding the fading away
> of the parallel port, poor quality serial ports and, most important, the
> need for software to "wiggle pins" on the port. Keep in mind, this is in the
> context of "bootstrapping" or starting with PIC's for the beginner who likes
> to do things for his/her self.
That's the area I work in.
> A long time ago, Tony Nixon designed a programmer that would work on even a
> low quality serial port (and it has been tested by other people with USB to
> serial adapters) without ANY software! And it is very simple:
>
> <http://www.piclist.com/techref/com/picnpoke/www/http/projects/prog.html>
> You just jumper the handshaking signals on the serial port so that the data
> flys out the end at 1200n7 and supply the programming voltage yourself.
That programmer is the inspriation for my Trivial BootStrap 555 programmer.
Same concept implemented with 555 timers. You can find it here:
http://www.finitesite.com/d3jsys/tbs555
It's not a finished work. The TX data/clock latching works. However, I'm still
working on getting the receiver to work so that the PIC can send back verification
information.
I'm thinking I should finalize the TX only version (code named "Black Hole" ;-)
just to get the project off the ground.
> I really like that the minimum commands required to tell the PIC to load
> this data are documented on that page. This removes the "magic" of the PIC
> device programmer and allows the true hacker (in the true sense of that
> word) to see exactly what is happening.
Very true. However, I'm not sure that deep understanding is the point. As a
bootloader based developer, a simple bootstrap programmer that can get a chip
bootloaders installed is a boon. My belief system in that the programmer is only
an instrument that gets in the way of doing to real work. The simpler and more
out of the way it is, the better off I am as a developer.
> The trick is that although no software is actually needed, translating the
> hex file into the data stream that needs to be sent out the serial port is
> something that a program should be used to do, and the only program that has
> ever been written to do it is closed source (source lost) and for the
> windows environment.
Not hard to duplicate. As my page points out I'm planning on adding a module to
Alain Gibaud's pikdev programmer to drive the beast.
Maybe I should task one of my interns to write some Perl/Python code that will
do the hex file conversion.
> I'm really curious about two things:
>
> A) is there another programmer that is basically the same as this one?
> Serial port, a few basic components and no PIC, just taking a datastream and
> not a program...
See above.
> B) does anyone see any value in writing some open source software to
> translate hex files into the datastream needed for the programmer?
Yup.
> If someone writes the program, I will try to host it at piclist.com so it
> would be a truly host independent programming solution... Just past your hex
> file into a form on the web page, push the button, download the result and
> copy it out your serial port.
I think I'll put my students to the task. Maybe even better would be a java applet
so that anyone could run it in a web browser.
BAJ
