Teensy 2.0 Pinout Diagram
 -------------------------
USB is on top in the diagram.
Inner columns are pin numbers, outer columns are port+bit pin name.
```
ground  GND      USB      VCC   +5v power
        B0 0            21 F0
        B1 1            20 F1
        B2 2            19 F4
        B3 3            18 F5
        B7 4            17 F6
SCL     D0 5            16 F7
SDA     D1 6            15 B6
        D2 7            14 B5
        D3 8            13 B4
        C6 9            12 D7
        C7 10           11 D6   Do not use pin D6 for scanning keyboard matrix
                                LED on pin D6 pulls voltage down and will always return low

BOTTOM (USB on top, left to right)
PIN#    port+bit        function
23      D5
        VCC             5v power
        GND             ground
        RST             reset
22      D4

MID (below USB, left to right)
PIN#    port+bit        function
24      E6
Ref
```

Teensy pin out with port names is on http://www.pjrc.com/teensy/td_digital.html
Identifying and naming ports is useful when instantiating RowPorts and ColPorts.
Keybrd library was tested on Teensy 2.0