Subject:
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Re: Pic16c84 programming with Handyboard
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Tue, 5 Nov 1996 18:11:52 GMT
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Original-From:
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Fred G. Martin <fredm@^stopspammers^media.mit.edu>
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Viewed:
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2442 times
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David --
The MAX662 chip I used on the last beta rev was not the magic bullet I
hoped. Not only is there possibly the rise time problem you mention,
but when the thing turns off, it outputs 5v. The PIC needs a swing
from 0v to 12v to enter program mode. So I ended up with a transistor
switch also. Thus the program ckt is the MAX662 plus two transistors
(needed to let a 0-5v logic signal turn on and off a 12v level).
I am scheduled with my publisher to work on the Expansion Board over
the Dec holidays. Right now I haven't been planning to include the
PIC programmer on the Expansion Board, but I could be convinced
otherwise.
I guess the main reason to include a PIC pgm circuit on the Exp Bd
would be to encourage cross-platform use of PICs. There seem to be a
lot of readily available and cheap designs for building PC-parallel
port PIC programmers. But maybe there is nothing out there for Mac
users? David, is your PIC programmer code written in IC?
Enclosed is a copy of my last public message regarding my Exp Bd
plans. Comments and discussion are still welcome. Especially if you
want that PIC circuit, now is the time to argue for it!
-Fred
To: handyboard
Subject: status of the expansion board
Date: Wed, 10 Jul 96 20:18:06 -0400
From: "Fred G. Martin" <fredm>
X-Mts: smtp
Hi all,
Many people are asking about the Expansion Board. It has been on the
"back burner" because my publisher is demanding text, not technology.
But I do plan to release another rev this summer. My ideas about what
should go on it have evolved, due to feedback from many of you,
licensing concerns, and other issues.
Right now, this is the planned feature set:
* 4 LEGO sensor inputs (shaft encoder & reflectance sensor)
* 4 high-impedance sensor inputs
* 8 or 16 additional analog inputs
* 4 servo motor outputs
* 2 or 3 high-current digital outputs (for relays, LEDs, etc.)
* Polaroid ranging sensor connector & support circuitry
* prototyping area
The main changes from the design published on the web site are the
removal of the PIC circuit (takes up too much room; people can still
connect PICs as they wish to an HB with just a few wires) and the
addition of LEGO sensor circuitry (LEGO agreed to allow me to
officially support their sensors!) and digital outputs (most requested
feature).
I am not promising a release date on this b/c writing is the #1
priority, but as I have said, I expect it will happen this summer.
Public/private comments welcome.
-Fred
> Fred, While working on this project I looked at your schematic for creating
> the 12V programming voltage on the expansion board. You used a MAX chip if
> memory serves. I looked up the spec sheet for the MAX part and noticed
> that the rise time of the 12V is much larger than that required for getting
> the pi16c84 into program/verify mode. I am no analog genius, so I need
> some way to do this quickly. I modified my board so that I could
> disconnect my batteries, so I should have 12V on my board already from the
> wall transformer (as long as I put the charger into Zap mode). Right now I
> am using a simple transistor switch to control the programming voltage, but
> if anyone has a better suggestion, I am up for it.
>
> Also, since I am just getting into PICs myself, if anyone has any simple
> 16c84 code that I could use to test my programmer with, it would be great.
> I already have a simple LED flasher going, but some other tests would be
> nice.
>
>
> -Dave Negro
> dln2@cornell.edu
>
>
> > I have got a little question about the expansion board: at the HB
> > home page, I
> > could read that the exp. board was not yet finished and that the
> > programming of the
> > PIC16C84 is impossible. In fact, I did not found any layout of the two
> > layers of the PCB,
> > without silkscreen. Can anybody help me?
>
>
>
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Message is in Reply To:
 | | Re: Pic16c84 programming with Handyboard
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| David, Althuogh I don't have an expansion board either, I am in the middle of testing some code that I wrote to program pi16c84s. Everything seems to be working well, I just want to keep on testiong it before releasing it. I wrote it such that it (...) (28 years ago, 5-Nov-96, to lugnet.robotics.handyboard)
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