Interfacing a 16-key keypad with the BX24

Started by November 14, 2004

Hello,

This is my very first post on this forum and am a newbie to the ways
of electronics and I'm looking for a solution to a problem that I've
come across in my very first project.
I'm using a BX-24 and a Matrix Orbital LCD display and have interfaced
a 16-key keypad to this setup. Is there anyway I can use this keypad
to get to enter the entire alphabet(A-Z) and the numbers (0-9)? I
guess I could use a function to check if the a key is being pressed
repeatedly in a given time frame to enter multiple characters using
one key. Besides this method is there any other ways to go about doing
this.
Thanks very much for all your input.

-Madusha




Hey,
I have used the BasicX with the Matrix Orbital and a keypad before but I
only used the 12 key version.
1) I think one way you could accomplish your goal is to designate one
of the keys on your keyboard as a switch key. When your controller detects
that the switch key has been hit the program would generate an alternate set
of values for the keys being pressed. You will need to switch or scroll
through three sets of alternate values in order to get all the alphabet and
the 0-9. If it were me I would send something back to the LCD indicating
which of the three sets of values the keyboard is currently sending.(You
could select between as many value sets as you want).
2) Another way would be to use two of the inputs on the basicX to set
the values. (You could select between 4 value sets).
3) One final idea is to use one of the analog inputs and a selector
switch tied to a resistor divider network. As you switch between points on
the resistor network you get different voltages(at the analog input) and
have your program change the value set for the keyboard based on the voltage
level.(You could select between as many value sets as you want but I would
think 9 is the practical limit).
You could use lookup tables in any case for the different value sets.
Hope this helps
Harry

-----Original Message-----
From: M G [mailto:]
Sent: Sunday, November 14, 2004 3:29 AM
To:
Subject: [BasicX] Interfacing a 16-key keypad with the BX24
Hello,

This is my very first post on this forum and am a newbie to the ways of
electronics and I'm looking for a solution to a problem that I've come
across in my very first project.
I'm using a BX-24 and a Matrix Orbital LCD display and have interfaced a
16-key keypad to this setup. Is there anyway I can use this keypad to get to
enter the entire alphabet(A-Z) and the numbers (0-9)? I guess I could use a
function to check if the a key is being pressed repeatedly in a given time
frame to enter multiple characters using one key. Besides this method is
there any other ways to go about doing this.
Thanks very much for all your input.

-Madusha ------------------------ Yahoo! Groups Sponsor --------------------~-->
$9.95 domain names from Yahoo!. Register anything.
http://us.click.yahoo.com/J8kdrA/y20IAA/yQLSAA/dN_tlB/TM
--------------------------------~- Yahoo! Groups Links



Hi

I have used the 16 keys keypad before but for a
different purpose. For yours, you could try encoding
it like a normal telephone. (ie pressing 2 would cycle
through A, B, C and 2 and pressing 3 would cycle
through D,E, F and 3 and so on). For this you would
only require 10 keys (0-9) and the rest you can used
for other functions.

HTH
VIdya
--- M G <> wrote:

>
> Hello,
>
> This is my very first post on this forum and am a
> newbie to the ways
> of electronics and I'm looking for a solution to a
> problem that I've
> come across in my very first project.
> I'm using a BX-24 and a Matrix Orbital LCD display
> and have interfaced
> a 16-key keypad to this setup. Is there anyway I can
> use this keypad
> to get to enter the entire alphabet(A-Z) and the
> numbers (0-9)? I
> guess I could use a function to check if the a key
> is being pressed
> repeatedly in a given time frame to enter multiple
> characters using
> one key. Besides this method is there any other ways
> to go about doing
> this.
> Thanks very much for all your input.
>
> -Madusha >
>

__________________________________