Hi
I am designing a digital code lock and using a 4*3 keypad (http://docs-europe.electrocomponents.com/webdocs/0033/0900766b800338ed.pdf)
How can I found out which connections are the rows and columns as it is not specified on the datasheet.
Thanks very much.

 

Hi
I am designing a digital code lock and using a 4*3 keypad (http://docs-europe.electrocomponents.com/webdocs/0033/0900766b800338ed.pdf)
How can I found out which connections are the rows and columns as it is not specified on the datasheet.
Thanks very much.

Ohmmeter...

 

Yes my lecturer was saying that but I didn't fully understand what I am meant to do. what exactly do I do?

 

Yes my lecturer was saying that but I didn't fully understand what I am meant to do. what exactly do I do?

I'm assuming you're trying to figure which pins relate to which rows and columns with respect to the keyboard, yes?

Well, think about what a key (switch) does in relation to those rows and columns. Then use an ohmmeter to identify which key is represented by which row and which column.

 

It is shown on page 6 of the datasheet.
For a 4x4 keypad there are 8 pins, 4 rows x 4 columns.
For a 4x3 keypad there are 7 pins, 3 columns x 4 rows as shown on the datasheet.

 

It is shown on page 6 of the datasheet.
For a 4x4 keypad there are 8 pins, 4 rows x 4 columns.
For a 4x3 keypad there are 7 pins, 3 columns x 4 rows as shown on the datasheet.

Ha...I didn't even realize he posted one. You shouldn't have told him...he would have learned more the hard way.

 

The information is on the datasheet page 6.

X1 connects to 1,4,7 & *, etc.

Y1 connects to 1,2 & 3, etc.

Still not sure?

 

Never even saw that to be honest. Thanks for that cheers.

 

But do you know whether you have a matrix or a common point keypad? Count the number of pins and compare to the data sheet.

 

Though I had it wired up correctly but looks like I dont. The way I connected it was the row 1,2 & 3 are X1,X2 & X3 respectively. And the columns are Y1,Y2,Y3 & Y4.

 

Though I had it wired up correctly but looks like I dont. The way I connected it was the row 1,2 & 3 are X1,X2 & X3 respectively. And the columns are Y1,Y2,Y3 & Y4.

Have you tried an ohmmeter yet?