NNTP-Posting-Date: Tue, 26 Nov 2002 18:45:48 -0600
From: firstname.lastname@example.org (John Fields)
Subject: Re: circuit wanted-SQUARE PULSE GENERATOR
Date: Tue, 26 Nov 2002 23:15:10 GMT
Organization: Austin Instruments, Inc.
References: <1038144646.265208@athprx02> <email@example.com> <3DE24901.firstname.lastname@example.org>
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On Tue, 26 Nov 2002 20:55:24 GMT, Jim Thompson
>I think two buttons, plus a display, can give you an *infinite* number
I'm pretty sure you're right.
I've currently got a project where I'm using a telco formatted 3X4
keypad which, instead of presenting * and #, presents "N" and "Y".
The display is a 2X16 LCD display used to communicate with the
On power-up the LCD displays "PRESS N TO SCROLL MENU" and when you
do, the various options available are presented, with successive "N"
pressings, one at a time, in a circular array. When you get to a
selection you like you are prompted to press "Y", and then there are
various questions you are asked which you must answer with either
the "Y"(yes) or "N"(no) keys which further define what you want the
machine to do.
I'm using a 3X4 keypad because some of the menu choices require
numerical input and it would be a huge PITA to have to do it with
just the "N" and "Y" switches, but it _could_ be done, for sure.
I had a project, years ago, where I had to scroll a menu and do
numerical _and_ alpha input from a 4X4 keypad, and if you're
interested I'll post a picture of the keypad overlay to abse.
There _is_ another interesting way to do it, and that's to use a
quadrature encoder with an integral pushbutton switch as the input
device. The only real estate that's required to do it this way is a
1/4"(?) hole in the front panel, the front panel area the knob
needs, and the volume needed behind the panel for the device itself
(and the wiring, if the PCB is remote from the encoder). The
penalty is the extra code which has to be written, but once that's
done and amortized over a couple of million units it's almost like
it wasn't there at all, huh?
Professional circuit designer