Make: Volume 87

In order to find the lowest value, we can use the

ndActiveButton(); function (Figure

L

) . This

function cycles through all the incoming values

and determines which is the lowest. If any of them

are under 100, then it’s likely a button is being

pressed. If you made your own touch matrix, it’s

possible these numbers are different. You can

use a calibration function to determine a baseline

value (see Volume 86, pages 96–97), or just

check manually what the values tend to be when

something is pressed.

If you’re getting erratic readings, it’s possible

that your resistive material isn’t fully separating

your conductive rows and columns, or that ...