GPIO pins

From GPIO.h

// Definition of tPin. Pins are named `PIN_XY' 
// where X is the port letter and Y is the pin number
typedef enum {
    PIN_A0, PIN_A1, PIN_A2, PIN_A3, PIN_A4, PIN_A5, PIN_A6, PIN_A7,
    PIN_B0, PIN_B1, PIN_B2, PIN_B3, PIN_B4, PIN_B5, PIN_B6, PIN_B7,
    PIN_C0, PIN_C1, PIN_C2, PIN_C3, PIN_C4, PIN_C5, PIN_C6, PIN_C7,
    PIN_D0, PIN_D1, PIN_D2, PIN_D3, PIN_D4, PIN_D5, PIN_D6, PIN_D7,
    PIN_E0, PIN_E1, PIN_E2, PIN_E3, PIN_E4, PIN_E5, PIN_E6, PIN_E7,
    PIN_F0, PIN_F1, PIN_F2, PIN_F3, PIN_F4, PIN_F5, PIN_F6, PIN_F7,
    PIN_COUNT, PORT_COUNT = PIN_COUNT / 8,
} tPin;