CrossRoads:
@liudr, Where did capacitive sensors come into play? I don't see any mention of that.I'm treating the request as the library driving 1 of 10 columns low, and reading the rows to see if any pin was pulled low by a button being closed.
Then back high and the next column low and the rows scanned, etc.
OP said touch matrix so I assumed cap sensing. Could be resistive sensing or just a casual use of word.
BTW, will there be two or more buttons pressed at the same time? That is the biggest problem for simple keypad libs.