Make: Volume 87

void setup() {

for (int i = 0; i < numRows; i++) {

pinMode(rows[i], INPUT_PULLUP);

}

for (int i = 0; i < numCols; i++) {

pinMode(col s[i], IN PU T);

}

Serial.begin(960 0);

}

This is where the code gets a bit tricky. We’re

going to fill every element in the second array by

cycling through rows and then columns. We can

see what column we’re in because we’ve set it to

OUTPUT, and then cycle through all the rows inside

of it. This way we don’t need as many pins, because

we are isolating each row.

Upload this code (Figure

J

) to your Arduino and

test it out! Have a look in the serial monitor to see

the output.

3. TEST YOUR PRESSURE TOUCH

MATRIX