Push Button Key Matrix

[wordizlife]

Hey guys,

I am making a 4 button key matrix for my project. The matrix will be directly connected to 5 pins on the microcontroller. Below is a link to an image of my schematic.

http://imageshack.us/photo/my-images/195/buttonschem.png/

Is there anything any of you would suggest I watch out for? Missing diodes for example?

Thanks!

[asmboy]

as drawn this is not a matrix
it is just 4 switches with a common

BTW: I'm always eager to learn a new trick,
but is there any reason you are using two poles to switch??

[wordizlife]

If I am not mistaken that is a key matrix.

Maybe this schematic will be clearer:

http://imageshack.us/photo/my-images/7/screenshot20120418at809.png/

I am only using two poles in this schematic because my push button has 4 connections and the pattern for this component fit perfectly.

[asmboy]

OK have it your way
Though, for at least the last 4o years or so of my professional practice,
I thought a matrix involved rows ( plural ) and columns that were interconnected ...

SO, if i were wiring a matrix of 4 switches i would use
ONLY 4 wires TOTAL.

You seem to have 5 - so i still will not call it a matrix.

Sorry but IMB, its just a garden variety 1 of 4 selector.

[Mike Walne]

OK. So you could call it a 1*4 matrix.

The general idea with a switching matrix is to reduce the number of external WIRES to a MINIMUM.

This is achieved by making the matrix as near square as possible.

In your case that's 2*2.

Mike

[wordizlife]

Yes that makes sense. Thanks. So I'm guessing that there is nothing more to it then that?
As long as there is nothing that I should watch out for that could damage my PIC or give me unwanted errors I am good to go.