gnupic: DIY USB programmer ?
Subject:
Re: DIY USB programmer ?
From:
David Willmore ####@####.####
Date:
14 Jan 2005 01:15:45 +0000
Message-Id: <200501140101.j0E11oAx013658@localhost.localdomain>
> > For those who just want to build the think from digikey parts,
>
> Radio Shack David. The US gold standard is parts from the RatShack parts
> drawers as expensive as they may be.
Hmmm, this is where we're going to have an issue. You can't get a PIC
at radio shack. Nor can you get the PCB. What parts of this programmer
do you want to put that restriction on? Just the bootstrap portion?
> > > I took a 5 minute look at Pikdev. It'll require adding a new type of
> > > programmer
>
> Port, not programmer.
Hmmm, we have dumb parallel, dumb serial, bootstrap serial, and 'smart' serial.
We'll probably need to come up with a new term. "interface"?
> > > 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.
>
> I found it. A new port is instantiated in hardware.cc. I got a failure of
> pkp when I set the type=555 in .pkprc. So it's just a line of code.
Does this include the work to add a new GUI pannel for configuring the
port?
> > I thought it would fit in pretty easily. You'd need to make a new
> > programmer
> > dialog for it, but it would only have to have a pulldown for serial port
> > as an
> > option--maybe we'd need some calibration stuff in there too, huh?
>
> I'll leave that up to Alain to decide the interface. I'll do all of my
> testing using pkp and the .pkprc file from the command line.
Good idea. I only use the GUI, so I hadn't thought about that. It would
probably be a good debugging too to do it with pkp.
> > I've been using it for use with your THVP for a while now and I've had great
> > luck. For those PICs that it didn't support, I found that it wasn't that
> > hard to add it. Of course, I have to finish submitting that... Sorry
> > Alain...
>
> I happy to find out that it works. Is there a Windows port for pikdev. I
> didn't see anything for it in the download section.
Not to my knowledge. It's a KDE app, so you need Qt--which is commercial
for the Windows platform. So, we might need a professional developer for
that port. Or integrate the backend into some other program. pkp might
run there more easily.
> > NPNs if they don't have any special requirements are damn near free, so don't
> > feel bad. Just follow these kit building guidelines: If you have to use an
> > expensive part, use it. If you can avoid it by using a few common parts,
> > do so. If you've already used a part using it again is fine.
>
> Then I'm in pretty good shape.
I buy them by the pound. :) I'd love to have some use for more of them--say
if one of the clubs I work with would offer to kit this.
> > Having 'kitted' a few hundred kits, can safely say that the worst kits to
> > prepare are the analog ones where you have *one* of this odd value, *one*
> > of that, *one* of some other identical value, but 1% tolerance, etc. I love
> > digital designs that are like "C1-C50 .1uF momo cap, R1-R18 10K 5% 1/8W,
> > R19-R40 1K 5% 1/8W" Woooo Hooo! That's three parts as I count them. :)
>
> Understood. I think I'll need 3 resistor values along with the pots.
> There are two cap values. I'll have to have the zener and a regular
> signal diode. And of course the sprinking of NPNs along with the 556 itself
> which could be implemented with 2 555s in a pinch.
>
> But it's a handful of cheap plentiful parts.
Wonderful! ;)
> > I'm always leary of capacitors as they have the largest tolerance specs of
> > any common electrical part. Resistors you can get in any arbitrary tolerance.
> > Inductors tend to be available in better than 10% tolerances. But caps,
> > sheesh. Common 'lytics are +70%/-20% tolerance! Do a timing circuit with
> > them, not without calibration. Now, expensive mylar caps can be 1%, but
> > they're hard to find and they're not cheap.
>
> That's why I planned on having the pots for tuning the timers.
>
> What's the typical tolerances on tantulums?
That I'm not sure. Probably no better than +/- 10%. If you need a pot, you
need a pot, they're not big issue.
> > Keep up the good work, Byron!
>
> I'm very interested now because I can see the light at the end of the tunnel.
> The bootstrapper will serve all of my immediate needs because once it's
> coupled with pikdev I'll be able to program all the 18F chips that I've
> been sampling along with the 12F parts that I've been drooling over. I'll
> finally retire Brian Lane's picprog that I've been helping limp along for
> the last few years.
I think that's two wins. :) It removes the need to support picprog--which
is probably already dead with TLVP/THVP with pkp. It also may increase the
interest in Pikdev which helps us all.
Cheers,
David
