More buttons with less buttons

[Rednas]

One other possibility of midibox64 is a matrix for buttons. 8x8 is implented already. 16x32 is on it's way (for organist who need a lot of buttons for 3 manuals etc.) In this way you have eight outputs times eight inputs i.e. 64 buttons. If you use push buttons to send midi messages, for example for instruments, you can use 64 buttons, but you also can use a switch that chooses between several outputs. In this way you can minimise buttons and use less than 64 for sending 64 midimessages.

More about matrices in the midification topic.  

[scoubidoo]

Very usefull for a boing 747 board too !  ;D

[pay_c]

Wait a mmt. Don´t matrix solution always implement a max number of three pushed buttons at one time (in worst case).

Imagine:

Let´s say button between 2&2 is pushed (row 2 and coloumn 2). Then 2&4. Then 4&2. Up to now every button can be identified (although a little software prob). Now, when 4&4 is pushed, it won´t be recognized, right?

Just asking myself... Greetz!

[Rednas]

It is a scanning matrix at least that's what I think, (otherwise you'll be right and this matrix is not such a good idea). This means you give a signal at one row, and then read all the columns. Then you give a signal on the next row and read the outputs.

In your example:

row 2 is scanned: signal at column 2 and 4 (2x2 and 2x4 are read positive)

next scan row 3

no signals

scan row 4

4x2 and 4x4 positive

So no problem this way.

[pay_c]

Aaaah! Cool! *Light going on in my head*

Thnx for that info!

[jimhenry]

It is a scanning matrix at least that's what I think, (otherwise you'll be right and this matrix is not such a good idea). This means you give a signal at one row, and then read all the columns. Then you give a signal on the next row and read the outputs.

In your example:

row 2 is scanned: signal at column 2 and 4 (2x2 and 2x4 are read positive)

next scan row 3

no signals

scan row 4

4x2 and 4x4 positive

So no problem this way.

Yes, this is exactly the way it works. You do need a diode for every switch to avoid some other problems and I have a writeup that I am working on for scanned matrices that explains this.