Parallax 4X4 matrix keypad
Archiver
Posts: 46,084
In a message dated 6/17/2004 2:59:06 PM Eastern Daylight Time,
CHRIS@R... writes:
> Has anyone used the Parallax (actually Grayhill) 4X4 matrix keypad.
> If so, can you tell me how many pins I would need to interface it to
> the BS2? Are there any sample programs out there? Is there a
> different kind of keypad that only uses one wire for communication
> instead of a bunch like this one may use?
>
Depends on what you want the matrix to do. Just to light LEDs it would take
8 I/O lines. For something heavier duty you might want to use a 595 shift
register or maybe a TPIC6595. Both take 3 I/O lines, I think.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
CHRIS@R... writes:
> Has anyone used the Parallax (actually Grayhill) 4X4 matrix keypad.
> If so, can you tell me how many pins I would need to interface it to
> the BS2? Are there any sample programs out there? Is there a
> different kind of keypad that only uses one wire for communication
> instead of a bunch like this one may use?
>
Depends on what you want the matrix to do. Just to light LEDs it would take
8 I/O lines. For something heavier duty you might want to use a 595 shift
register or maybe a TPIC6595. Both take 3 I/O lines, I think.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
Has anyone used the Parallax (actually Grayhill) 4X4 matrix keypad.
If so, can you tell me how many pins I would need to interface it to
the BS2? Are there any sample programs out there? Is there a
different kind of keypad that only uses one wire for communication
instead of a bunch like this one may use?
Thanks,
Chris
Yes, check the Nuts & Volts section of our web site.
<Jon's Standard Reminder Off>
There are at least a couple articles on keypad scanning.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: christopher41877 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=kIVm8o8PwWcfTdU1rEUgCHQiKFbQtPBxUF23t4LGvLGuVs84rBJ4w4yqdZwSrPArJUlP1pyuVXu2ucIKJz4Iniy0Wt5D-Qc]CHRIS@R...[/url
Sent: Thursday, June 17, 2004 1:19 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Parallax 4X4 matrix keypad
Hi,
Has anyone used the Parallax (actually Grayhill) 4X4 matrix keypad.
If so, can you tell me how many pins I would need to interface it to
the BS2? Are there any sample programs out there? Is there a
different kind of keypad that only uses one wire for communication
instead of a bunch like this one may use?
Thanks,
Chris
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject
and Body of the message will be ignored.
Yahoo! Groups Links
This message has been scanned by WebShield. Please report SPAM to
abuse@p....
I have a same question before. You can use MM74C922 as keypad encoder.
You can go to
http://www.geocities.com/SiliconValley/Orchard/6633/projects.html
for the code and schematic.
It is good, cheap and very easy solutions. The only drawback is that it will
take 5 I/O pins (comparing with RS232 keypad encoder that uses less pins).
Regards,
Bronson Alex
Original Message
From: "christopher41877" <CHRIS@R...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, June 18, 2004 1:19 AM
Subject: [noparse][[/noparse]basicstamps] Parallax 4X4 matrix keypad
> Hi,
>
> Has anyone used the Parallax (actually Grayhill) 4X4 matrix keypad.
> If so, can you tell me how many pins I would need to interface it to
> the BS2? Are there any sample programs out there? Is there a
> different kind of keypad that only uses one wire for communication
> instead of a bunch like this one may use?
>
> Thanks,
>
> Chris
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
> In a message dated 6/17/2004 2:59:06 PM Eastern Daylight Time,
> CHRIS@R... writes:
>
>
> > Has anyone used the Parallax (actually Grayhill) 4X4 matrix
keypad.
> > If so, can you tell me how many pins I would need to interface it
to
> > the BS2? Are there any sample programs out there? Is there a
> > different kind of keypad that only uses one wire for
communication
> > instead of a bunch like this one may use?
> >
>
> Depends on what you want the matrix to do. Just to light LEDs it
would take
> 8 I/O lines. For something heavier duty you might want to use a
595 shift
> register or maybe a TPIC6595. Both take 3 I/O lines, I think.
>
> Sid
Keypad = input = 74HC165 and 3 lines
2 units would handle 16 inputs (4 x 4=16 butttons on the keypad) so
a pair of 165's *could* handle a 4x4 keypad. I don't have the code
and have not tried to use these, but I just wanted to review the
possibility.
Dave
I used 5 BS2 pins to control '595 and '165 shift registers.
I only used 4 output and 4 input, so I still have 4 output and 4
inputs left over. Typically, this would have taken 8 pins (4 output
and 4 input) if done in classical textbook approach.
Below is the code I used.
'{$STAMP BS2}
'{$PBASIC 2.0}
CLK CON 0 'pin 11 of 595, pin 2 of 165 orange
D595 CON 1 'pin 14 of 595 purple
CS595 CON 2 'pin 12 of 595 brown
D165 CON 3 'pin 9 of 165 grey
CS165 CON 4 'pin 1 of 165 white/red
db VAR Bit
press VAR Bit
press = 0
key VAR Nib
keys VAR Byte
Row VAR Nib
Col VAR Nib
pattern VAR Byte
switches VAR Byte
LOW CS595
HIGH CS165
Again:
pattern = %00000001
GOSUB Keyscan
IF press = 0 THEN Again
DEBUG "Key pressed = ", DEC Keys & %00001111, CR
press = 0
GOTO Again
Keyscan:
FOR row = 0 TO 3
SHIFTOUT D595, Clk, MSBFIRST, [noparse][[/noparse]pattern]
PULSOUT CS595, 1
PULSOUT CS165, 1
SHIFTIN D165, Clk, MSBPRE, [noparse][[/noparse]col]
key = NCD col
IF key <> 0 THEN push
pattern = pattern << 1
NEXT
db = 0
RETURN
Push:
IF db = 1 THEN Done
db = 1
press = 1
keys = (row*4) + (key-1)
LOOKUP keys, [noparse][[/noparse]1,2,3,10,4,5,6,11,7,8,9,12,14,0,15,13], keys
Done:
RETURN
--- In basicstamps@yahoogroups.com, "christopher41877" <CHRIS@R...>
wrote:
> Hi,
>
> Has anyone used the Parallax (actually Grayhill) 4X4 matrix
keypad.
> If so, can you tell me how many pins I would need to interface it
to
> the BS2? Are there any sample programs out there? Is there a
> different kind of keypad that only uses one wire for communication
> instead of a bunch like this one may use?
>
> Thanks,
>
> Chris