Keypad controller

Hi all, I want to implement a 6x6 matrix keypad controller(scanner) in CPLD.I have implemented it for detcting a single key press. I wanted to know , hoe to go about the design for detecting multiple keys pressed at the same time. Thanks in advance, Praveen

Asked By: praveen_n
On: May 31, 2005 2:51:46 AM

Comments(2)

hi rskurane, Thanks for your comments. What i am planning to do is , i will scan the rows (6 of them sequentially) , when all the 6 rows are scanned i will send the 36 bit output(each bit corresponds to each individual key '0' indicates pressed)to the controller.The scan rate for each row is approximately 32 msec , so every 32x6=192 msec i will be sending a code to controller(HCS12). I want your comments on this implementation. Regards, Praveen

Comment By: praveen_n
On: Jun 2, 2005 11:49:33 PM

well basically you have to do multiple scans for detecting the row and the column to detect. When you do press a key, what you are doing is selecting a rwo, so in your code have a case statement that checks for each row and in there check for the column pressed.

Comment By: rskurane
On: Jun 2, 2005 3:00:12 PM

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