title: Arduino keypad matrix example? ( teensyduino )
body: <p>I'm a beginner using Arduino with a Teensy 3.2 board and programming it as a usb keyboard.
  I have two 4 button membrane switches. Their button contacts are on pins 1-8, and the 9th pin holds a soldered together wire of both membrane switches' "ground" line or whatever it's true name is; the line that completes the circuit. </p>
  
  <p>Basically when you press the buttons they are supposed to simply type "a, b, c..." respectively. I've been told I need to use a matrix for this.</p>
  
  <p>I'm looking for an example of how to code a keyboard matrix that effectively supports a one row/9 column line (or vice versa?) I've been unable to find that solution online.</p>
  
  <p>All I have so far is this code which, when the button on the second pin is pressed, sends tons of "AAAAAAAAAAAAAAAA" keystrokes. </p>
  
  <pre><code>void setup() {
    // make pin 2 an input and turn on the 
    // pullup resistor so it goes high unless
    // connected to ground:
    pinMode(2, INPUT_PULLUP);
    Keyboard.begin();
  }
  
  void loop() {
    //if the button is pressed
    if(digitalRead(2)==LOW){
      //Send an ASCII 'A', 
      Keyboard.write(65);
    }
  }
  </code></pre>
  
  <p>Would anyone be able to help?</p>