Scanning a button array

[Skirmitt]

I'm preparing a DJ midi controller project. This will have 15 potmeters, 16 buttons and 2 rotary encoders.
I will place the 16 buttons in a 4x4 array. The potmeters will be connected with 2 analog multiplexers. The rotary encoders will be on an IOC pin.

As this will be a DJ controller latency and so on has to be very good. I'm used to DJ'ing the classic way with vinyl so this has to feel very good.

If my PIC runs at 32 MHz. Will I be able to read the array and buttons all in one loop without missing one button press ? If a value has changed the MIDI command will be sent. That is all the PIC has to do. Or would it be better to put the buttons on INT pins ?

[arunb]

Interrupts would be faster.

For the Buttons you could use a I/O expander such as the MCP 23106 from Microchip, it can cater to 16 buttons, and has interrupt on change feature, thus freeing the PIC for other tasks.

thanks
a