text: //https://github.com/niteris/ArduinoSoftSpi
  
  #include <Arduino.h>
  #ifdef __arm__
  #ifdef CORE_TEENSY
  //------------------------------------------------------------------------------
  /** read pin value
   * @param[in] pin Arduino pin number
   * @return value read
   */
  static inline __attribute__((always_inline))
  bool fastDigitalRead(uint8_t pin) {
    return *portInputRegister(pin);
  }
  //------------------------------------------------------------------------------
  /** Set pin value
   * @param[in] pin Arduino pin number
   * @param[in] level value to write
   */
  static inline __attribute__((always_inline))
  void fastDigitalWrite(uint8_t pin, bool value) {
    if (value) {
      *portSetRegister(pin) = 1;
    } else {
      *portClearRegister(pin) = 1;
    }
  }
  #else  // CORE_TEENSY
  //------------------------------------------------------------------------------
  /** read pin value
   * @param[in] pin Arduino pin number
   * @return value read
   */
  static inline __attribute__((always_inline))
  bool fastDigitalRead(uint8_t pin){
    return g_APinDescription[pin].pPort->PIO_PDSR & g_APinDescription[pin].ulPin;
  }
  //------------------------------------------------------------------------------
  /** Set pin value
   * @param[in] pin Arduino pin number
   * @param[in] level value to write
   */
  static inline __attribute__((always_inline))
  void fastDigitalWrite(uint8_t pin, bool value){
    if(value) {
      g_APinDescription[pin].pPort->PIO_SODR = g_APinDescription[pin].ulPin;
    } else {
      g_APinDescription[pin].pPort->PIO_CODR = g_APinDescription[pin].ulPin;
    }
  }
  #endif  // CORE_TEENSY
  //------------------------------------------------------------------------------
  inline void fastDigitalToggle(uint8_t pin) {
   fastDigitalWrite(pin, !fastDigitalRead(pin));
   }
  //------------------------------------------------------------------------------
  inline void fastPinMode(uint8_t pin, bool mode) {pinMode(pin, mode);}
  #else  // __arm__
  #include <avr/io.h>
  #include <util/atomic.h>
  //------------------------------------------------------------------------------
  /**
   * @class pin_map_t
   * @brief struct for mapping digital pins
   */
  struct pin_map_t {
    volatile uint8_t* ddr;   /**< address of DDR for this pin */
    volatile uint8_t* pin;   /**< address of PIN for this pin */
    volatile uint8_t* port;  /**< address of PORT for this pin */
    uint8_t bit;             /**< bit number for this pin */
  };
  //------------------------------------------------------------------------------
  #if defined(__AVR_ATmega168__)\
  ||defined(__AVR_ATmega168P__)\
  ||defined(__AVR_ATmega328P__)
  // 168 and 328 Arduinos
  const static pin_map_t pinMap[] = {
    {&DDRD, &PIND, &PORTD, 0},  // D0  0
    {&DDRD, &PIND, &PORTD, 1},  // D1  1
    {&DDRD, &PIND, &PORTD, 2},  // D2  2
    {&DDRD, &PIND, &PORTD, 3},  // D3  3
    {&DDRD, &PIND, &PORTD, 4},  // D4  4
    {&DDRD, &PIND, &PORTD, 5},  // D5  5
    {&DDRD, &PIND, &PORTD, 6},  // D6  6
    {&DDRD, &PIND, &PORTD, 7},  // D7  7
    {&DDRB, &PINB, &PORTB, 0},  // B0  8
    {&DDRB, &PINB, &PORTB, 1},  // B1  9
    {&DDRB, &PINB, &PORTB, 2},  // B2 10
    {&DDRB, &PINB, &PORTB, 3},  // B3 11
    {&DDRB, &PINB, &PORTB, 4},  // B4 12
    {&DDRB, &PINB, &PORTB, 5},  // B5 13
    {&DDRC, &PINC, &PORTC, 0},  // C0 14
    {&DDRC, &PINC, &PORTC, 1},  // C1 15
    {&DDRC, &PINC, &PORTC, 2},  // C2 16
    {&DDRC, &PINC, &PORTC, 3},  // C3 17
    {&DDRC, &PINC, &PORTC, 4},  // C4 18
    {&DDRC, &PINC, &PORTC, 5}   // C5 19
  };
  //------------------------------------------------------------------------------
  #elif defined(__AVR_ATmega1280__)\
  || defined(__AVR_ATmega2560__)
  // Mega
  static const pin_map_t pinMap[] = {
    {&DDRE, &PINE, &PORTE, 0},  // E0  0
    {&DDRE, &PINE, &PORTE, 1},  // E1  1
    {&DDRE, &PINE, &PORTE, 4},  // E4  2
    {&DDRE, &PINE, &PORTE, 5},  // E5  3
    {&DDRG, &PING, &PORTG, 5},  // G5  4
    {&DDRE, &PINE, &PORTE, 3},  // E3  5
    {&DDRH, &PINH, &PORTH, 3},  // H3  6
    {&DDRH, &PINH, &PORTH, 4},  // H4  7
    {&DDRH, &PINH, &PORTH, 5},  // H5  8
    {&DDRH, &PINH, &PORTH, 6},  // H6  9
    {&DDRB, &PINB, &PORTB, 4},  // B4 10
    {&DDRB, &PINB, &PORTB, 5},  // B5 11
    {&DDRB, &PINB, &PORTB, 6},  // B6 12
    {&DDRB, &PINB, &PORTB, 7},  // B7 13
    {&DDRJ, &PINJ, &PORTJ, 1},  // J1 14
    {&DDRJ, &PINJ, &PORTJ, 0},  // J0 15
    {&DDRH, &PINH, &PORTH, 1},  // H1 16
    {&DDRH, &PINH, &PORTH, 0},  // H0 17
    {&DDRD, &PIND, &PORTD, 3},  // D3 18
    {&DDRD, &PIND, &PORTD, 2},  // D2 19
    {&DDRD, &PIND, &PORTD, 1},  // D1 20
    {&DDRD, &PIND, &PORTD, 0},  // D0 21
    {&DDRA, &PINA, &PORTA, 0},  // A0 22
    {&DDRA, &PINA, &PORTA, 1},  // A1 23
    {&DDRA, &PINA, &PORTA, 2},  // A2 24
    {&DDRA, &PINA, &PORTA, 3},  // A3 25
    {&DDRA, &PINA, &PORTA, 4},  // A4 26
    {&DDRA, &PINA, &PORTA, 5},  // A5 27
    {&DDRA, &PINA, &PORTA, 6},  // A6 28
    {&DDRA, &PINA, &PORTA, 7},  // A7 29
    {&DDRC, &PINC, &PORTC, 7},  // C7 30
    {&DDRC, &PINC, &PORTC, 6},  // C6 31
    {&DDRC, &PINC, &PORTC, 5},  // C5 32
    {&DDRC, &PINC, &PORTC, 4},  // C4 33
    {&DDRC, &PINC, &PORTC, 3},  // C3 34
    {&DDRC, &PINC, &PORTC, 2},  // C2 35
    {&DDRC, &PINC, &PORTC, 1},  // C1 36
    {&DDRC, &PINC, &PORTC, 0},  // C0 37
    {&DDRD, &PIND, &PORTD, 7},  // D7 38
    {&DDRG, &PING, &PORTG, 2},  // G2 39
    {&DDRG, &PING, &PORTG, 1},  // G1 40
    {&DDRG, &PING, &PORTG, 0},  // G0 41
    {&DDRL, &PINL, &PORTL, 7},  // L7 42
    {&DDRL, &PINL, &PORTL, 6},  // L6 43
    {&DDRL, &PINL, &PORTL, 5},  // L5 44
    {&DDRL, &PINL, &PORTL, 4},  // L4 45
    {&DDRL, &PINL, &PORTL, 3},  // L3 46
    {&DDRL, &PINL, &PORTL, 2},  // L2 47
    {&DDRL, &PINL, &PORTL, 1},  // L1 48
    {&DDRL, &PINL, &PORTL, 0},  // L0 49
    {&DDRB, &PINB, &PORTB, 3},  // B3 50
    {&DDRB, &PINB, &PORTB, 2},  // B2 51
    {&DDRB, &PINB, &PORTB, 1},  // B1 52
    {&DDRB, &PINB, &PORTB, 0},  // B0 53
    {&DDRF, &PINF, &PORTF, 0},  // F0 54
    {&DDRF, &PINF, &PORTF, 1},  // F1 55
    {&DDRF, &PINF, &PORTF, 2},  // F2 56
    {&DDRF, &PINF, &PORTF, 3},  // F3 57
    {&DDRF, &PINF, &PORTF, 4},  // F4 58
    {&DDRF, &PINF, &PORTF, 5},  // F5 59
    {&DDRF, &PINF, &PORTF, 6},  // F6 60
    {&DDRF, &PINF, &PORTF, 7},  // F7 61
    {&DDRK, &PINK, &PORTK, 0},  // K0 62
    {&DDRK, &PINK, &PORTK, 1},  // K1 63
    {&DDRK, &PINK, &PORTK, 2},  // K2 64
    {&DDRK, &PINK, &PORTK, 3},  // K3 65
    {&DDRK, &PINK, &PORTK, 4},  // K4 66
    {&DDRK, &PINK, &PORTK, 5},  // K5 67
    {&DDRK, &PINK, &PORTK, 6},  // K6 68
    {&DDRK, &PINK, &PORTK, 7},  // K7 69
  
  //pins_MIGHTYBOARD_REVE.h
    {&DDRG, &PING, &PORTG, 4},  // G4 70
    {&DDRG, &PING, &PORTG, 3},  // G3 71
    {&DDRJ, &PINJ, &PORTJ, 2},  // J2 72
    {&DDRJ, &PINJ, &PORTJ, 3},  // J3 73
    {&DDRJ, &PINJ, &PORTJ, 7},  // J7 74
    {&DDRJ, &PINJ, &PORTJ, 4},  // J4 75
    {&DDRJ, &PINJ, &PORTJ, 5},  // J5 76
    {&DDRJ, &PINJ, &PORTJ, 6},  // J6 77
    {&DDRE, &PINE, &PORTE, 2},  // E2 78
    {&DDRE, &PINE, &PORTE, 6}   // E6 79
  
  };
  //------------------------------------------------------------------------------
  #elif defined(__AVR_ATmega1284P__)\
  || defined(__AVR_ATmega1284__)\
  || defined(__AVR_ATmega644P__)\
  || defined(__AVR_ATmega644__)\
  || defined(__AVR_ATmega64__)\
  || defined(__AVR_ATmega32__)\
  || defined(__AVR_ATmega324__)\
  || defined(__AVR_ATmega16__)
  
  #if defined(VARIANT_MIGHTY)
  // Mighty Layout
  static const pin_map_t pinMap[] = {
    {&DDRB, &PINB, &PORTB, 0},  // B0  0
    {&DDRB, &PINB, &PORTB, 1},  // B1  1
    {&DDRB, &PINB, &PORTB, 2},  // B2  2
    {&DDRB, &PINB, &PORTB, 3},  // B3  3
    {&DDRB, &PINB, &PORTB, 4},  // B4  4
    {&DDRB, &PINB, &PORTB, 5},  // B5  5
    {&DDRB, &PINB, &PORTB, 6},  // B6  6
    {&DDRB, &PINB, &PORTB, 7},  // B7  7
    {&DDRD, &PIND, &PORTD, 0},  // D0  8
    {&DDRD, &PIND, &PORTD, 1},  // D1  9
    {&DDRD, &PIND, &PORTD, 2},  // D2 10
    {&DDRD, &PIND, &PORTD, 3},  // D3 11
    {&DDRD, &PIND, &PORTD, 4},  // D4 12
    {&DDRD, &PIND, &PORTD, 5},  // D5 13
    {&DDRD, &PIND, &PORTD, 6},  // D6 14
    {&DDRD, &PIND, &PORTD, 7},  // D7 15
    {&DDRC, &PINC, &PORTC, 0},  // C0 16
    {&DDRC, &PINC, &PORTC, 1},  // C1 17
    {&DDRC, &PINC, &PORTC, 2},  // C2 18
    {&DDRC, &PINC, &PORTC, 3},  // C3 19
    {&DDRC, &PINC, &PORTC, 4},  // C4 20
    {&DDRC, &PINC, &PORTC, 5},  // C5 21
    {&DDRC, &PINC, &PORTC, 6},  // C6 22
    {&DDRC, &PINC, &PORTC, 7},  // C7 23
    {&DDRA, &PINA, &PORTA, 0},  // A0 24
    {&DDRA, &PINA, &PORTA, 1},  // A1 25
    {&DDRA, &PINA, &PORTA, 2},  // A2 26
    {&DDRA, &PINA, &PORTA, 3},  // A3 27
    {&DDRA, &PINA, &PORTA, 4},  // A4 28
    {&DDRA, &PINA, &PORTA, 5},  // A5 29
    {&DDRA, &PINA, &PORTA, 6},  // A6 30
    {&DDRA, &PINA, &PORTA, 7}   // A7 31
  };
  #elif defined(VARIANT_BOBUINO)
  // Bobuino Layout
  static const pin_map_t pinMap[] = {
    {&DDRD, &PIND, &PORTD, 0},  // D0  0
    {&DDRD, &PIND, &PORTD, 1},  // D1  1
    {&DDRD, &PIND, &PORTD, 2},  // D2  2
    {&DDRD, &PIND, &PORTD, 3},  // D3  3
    {&DDRB, &PINB, &PORTB, 0},  // B0  4
    {&DDRB, &PINB, &PORTB, 1},  // B1  5
    {&DDRB, &PINB, &PORTB, 2},  // B2  6
    {&DDRB, &PINB, &PORTB, 3},  // B3  7
    {&DDRD, &PIND, &PORTD, 5},  // D5  8
    {&DDRD, &PIND, &PORTD, 6},  // D6  9
    {&DDRB, &PINB, &PORTB, 4},  // B4 10
    {&DDRB, &PINB, &PORTB, 5},  // B5 11
    {&DDRB, &PINB, &PORTB, 6},  // B6 12
    {&DDRB, &PINB, &PORTB, 7},  // B7 13
    {&DDRA, &PINA, &PORTA, 7},  // A7 14
    {&DDRA, &PINA, &PORTA, 6},  // A6 15
    {&DDRA, &PINA, &PORTA, 5},  // A5 16
    {&DDRA, &PINA, &PORTA, 4},  // A4 17
    {&DDRA, &PINA, &PORTA, 3},  // A3 18
    {&DDRA, &PINA, &PORTA, 2},  // A2 19
    {&DDRA, &PINA, &PORTA, 1},  // A1 20
    {&DDRA, &PINA, &PORTA, 0},  // A0 21
    {&DDRC, &PINC, &PORTC, 0},  // C0 22
    {&DDRC, &PINC, &PORTC, 1},  // C1 23
    {&DDRC, &PINC, &PORTC, 2},  // C2 24
    {&DDRC, &PINC, &PORTC, 3},  // C3 25
    {&DDRC, &PINC, &PORTC, 4},  // C4 26
    {&DDRC, &PINC, &PORTC, 5},  // C5 27
    {&DDRC, &PINC, &PORTC, 6},  // C6 28
    {&DDRC, &PINC, &PORTC, 7},  // C7 29
    {&DDRD, &PIND, &PORTD, 4},  // D4 30
    {&DDRD, &PIND, &PORTD, 7}   // D7 31
  };
  #elif defined(VARIANT_STANDARD)
  // Standard Layout
  static const pin_map_t pinMap[] = {
    {&DDRB, &PINB, &PORTB, 0},  // B0  0
    {&DDRB, &PINB, &PORTB, 1},  // B1  1
    {&DDRB, &PINB, &PORTB, 2},  // B2  2
    {&DDRB, &PINB, &PORTB, 3},  // B3  3
    {&DDRB, &PINB, &PORTB, 4},  // B4  4
    {&DDRB, &PINB, &PORTB, 5},  // B5  5
    {&DDRB, &PINB, &PORTB, 6},  // B6  6
    {&DDRB, &PINB, &PORTB, 7},  // B7  7
    {&DDRD, &PIND, &PORTD, 0},  // D0  8
    {&DDRD, &PIND, &PORTD, 1},  // D1  9
    {&DDRD, &PIND, &PORTD, 2},  // D2 10
    {&DDRD, &PIND, &PORTD, 3},  // D3 11
    {&DDRD, &PIND, &PORTD, 4},  // D4 12
    {&DDRD, &PIND, &PORTD, 5},  // D5 13
    {&DDRD, &PIND, &PORTD, 6},  // D6 14
    {&DDRD, &PIND, &PORTD, 7},  // D7 15
    {&DDRC, &PINC, &PORTC, 0},  // C0 16
    {&DDRC, &PINC, &PORTC, 1},  // C1 17
    {&DDRC, &PINC, &PORTC, 2},  // C2 18
    {&DDRC, &PINC, &PORTC, 3},  // C3 19
    {&DDRC, &PINC, &PORTC, 4},  // C4 20
    {&DDRC, &PINC, &PORTC, 5},  // C5 21
    {&DDRC, &PINC, &PORTC, 6},  // C6 22
    {&DDRC, &PINC, &PORTC, 7},  // C7 23
    {&DDRA, &PINA, &PORTA, 7},  // A7 24
    {&DDRA, &PINA, &PORTA, 6},  // A6 25
    {&DDRA, &PINA, &PORTA, 5},  // A5 26
    {&DDRA, &PINA, &PORTA, 4},  // A4 27
    {&DDRA, &PINA, &PORTA, 3},  // A3 28
    {&DDRA, &PINA, &PORTA, 2},  // A2 29
    {&DDRA, &PINA, &PORTA, 1},  // A1 30
    {&DDRA, &PINA, &PORTA, 0}   // A0 31
  };
  #else  // VARIANT_MIGHTY
  #error Undefined variant 1284, 644, 324, 64, 32
  #endif  // VARIANT_MIGHTY
  //------------------------------------------------------------------------------
  #elif defined(__AVR_ATmega32U4__)
  #ifdef CORE_TEENSY
  // Teensy 2.0
  static const pin_map_t pinMap[] = {
    {&DDRB, &PINB, &PORTB, 0},  // B0  0
    {&DDRB, &PINB, &PORTB, 1},  // B1  1
    {&DDRB, &PINB, &PORTB, 2},  // B2  2
    {&DDRB, &PINB, &PORTB, 3},  // B3  3
    {&DDRB, &PINB, &PORTB, 7},  // B7  4
    {&DDRD, &PIND, &PORTD, 0},  // D0  5
    {&DDRD, &PIND, &PORTD, 1},  // D1  6
    {&DDRD, &PIND, &PORTD, 2},  // D2  7
    {&DDRD, &PIND, &PORTD, 3},  // D3  8
    {&DDRC, &PINC, &PORTC, 6},  // C6  9
    {&DDRC, &PINC, &PORTC, 7},  // C7 10
    {&DDRD, &PIND, &PORTD, 6},  // D6 11
    {&DDRD, &PIND, &PORTD, 7},  // D7 12
    {&DDRB, &PINB, &PORTB, 4},  // B4 13
    {&DDRB, &PINB, &PORTB, 5},  // B5 14
    {&DDRB, &PINB, &PORTB, 6},  // B6 15
    {&DDRF, &PINF, &PORTF, 7},  // F7 16
    {&DDRF, &PINF, &PORTF, 6},  // F6 17
    {&DDRF, &PINF, &PORTF, 5},  // F5 18
    {&DDRF, &PINF, &PORTF, 4},  // F4 19
    {&DDRF, &PINF, &PORTF, 1},  // F1 20
    {&DDRF, &PINF, &PORTF, 0},  // F0 21
    {&DDRD, &PIND, &PORTD, 4},  // D4 22
    {&DDRD, &PIND, &PORTD, 5},  // D5 23
    {&DDRE, &PINE, &PORTE, 6}   // E6 24
  };
  //------------------------------------------------------------------------------
  #else  // CORE_TEENSY
  // Leonardo
  static const pin_map_t pinMap[] = {
    {&DDRD, &PIND, &PORTD, 2},  // D2  0
    {&DDRD, &PIND, &PORTD, 3},  // D3  1
    {&DDRD, &PIND, &PORTD, 1},  // D1  2
    {&DDRD, &PIND, &PORTD, 0},  // D0  3
    {&DDRD, &PIND, &PORTD, 4},  // D4  4
    {&DDRC, &PINC, &PORTC, 6},  // C6  5
    {&DDRD, &PIND, &PORTD, 7},  // D7  6
    {&DDRE, &PINE, &PORTE, 6},  // E6  7
    {&DDRB, &PINB, &PORTB, 4},  // B4  8
    {&DDRB, &PINB, &PORTB, 5},  // B5  9
    {&DDRB, &PINB, &PORTB, 6},  // B6 10
    {&DDRB, &PINB, &PORTB, 7},  // B7 11
    {&DDRD, &PIND, &PORTD, 6},  // D6 12
    {&DDRC, &PINC, &PORTC, 7},  // C7 13
    {&DDRB, &PINB, &PORTB, 3},  // B3 14
    {&DDRB, &PINB, &PORTB, 1},  // B1 15
    {&DDRB, &PINB, &PORTB, 2},  // B2 16
    {&DDRB, &PINB, &PORTB, 0},  // B0 17
    {&DDRF, &PINF, &PORTF, 7},  // F7 18
    {&DDRF, &PINF, &PORTF, 6},  // F6 19
    {&DDRF, &PINF, &PORTF, 5},  // F5 20
    {&DDRF, &PINF, &PORTF, 4},  // F4 21
    {&DDRF, &PINF, &PORTF, 1},  // F1 22
    {&DDRF, &PINF, &PORTF, 0},  // F0 23
    {&DDRD, &PIND, &PORTD, 4},  // D4 24
    {&DDRD, &PIND, &PORTD, 7},  // D7 25
    {&DDRB, &PINB, &PORTB, 4},  // B4 26
    {&DDRB, &PINB, &PORTB, 5},  // B5 27
    {&DDRB, &PINB, &PORTB, 6},  // B6 28
    {&DDRD, &PIND, &PORTD, 6}   // D6 29
  };
  #endif  // CORE_TEENSY
  //------------------------------------------------------------------------------
  #elif defined(__AVR_AT90USB646__)\
  || defined(__AVR_AT90USB1286__)
  // Teensy++ 1.0 & 2.0
  static const pin_map_t pinMap[] = {
    {&DDRD, &PIND, &PORTD, 0},  // D0  0
    {&DDRD, &PIND, &PORTD, 1},  // D1  1
    {&DDRD, &PIND, &PORTD, 2},  // D2  2
    {&DDRD, &PIND, &PORTD, 3},  // D3  3
    {&DDRD, &PIND, &PORTD, 4},  // D4  4
    {&DDRD, &PIND, &PORTD, 5},  // D5  5
    {&DDRD, &PIND, &PORTD, 6},  // D6  6
    {&DDRD, &PIND, &PORTD, 7},  // D7  7
    {&DDRE, &PINE, &PORTE, 0},  // E0  8
    {&DDRE, &PINE, &PORTE, 1},  // E1  9
    {&DDRC, &PINC, &PORTC, 0},  // C0 10
    {&DDRC, &PINC, &PORTC, 1},  // C1 11
    {&DDRC, &PINC, &PORTC, 2},  // C2 12
    {&DDRC, &PINC, &PORTC, 3},  // C3 13
    {&DDRC, &PINC, &PORTC, 4},  // C4 14
    {&DDRC, &PINC, &PORTC, 5},  // C5 15
    {&DDRC, &PINC, &PORTC, 6},  // C6 16
    {&DDRC, &PINC, &PORTC, 7},  // C7 17
    {&DDRE, &PINE, &PORTE, 6},  // E6 18
    {&DDRE, &PINE, &PORTE, 7},  // E7 19
    {&DDRB, &PINB, &PORTB, 0},  // B0 20
    {&DDRB, &PINB, &PORTB, 1},  // B1 21
    {&DDRB, &PINB, &PORTB, 2},  // B2 22
    {&DDRB, &PINB, &PORTB, 3},  // B3 23
    {&DDRB, &PINB, &PORTB, 4},  // B4 24
    {&DDRB, &PINB, &PORTB, 5},  // B5 25
    {&DDRB, &PINB, &PORTB, 6},  // B6 26
    {&DDRB, &PINB, &PORTB, 7},  // B7 27
    {&DDRA, &PINA, &PORTA, 0},  // A0 28
    {&DDRA, &PINA, &PORTA, 1},  // A1 29
    {&DDRA, &PINA, &PORTA, 2},  // A2 30
    {&DDRA, &PINA, &PORTA, 3},  // A3 31
    {&DDRA, &PINA, &PORTA, 4},  // A4 32
    {&DDRA, &PINA, &PORTA, 5},  // A5 33
    {&DDRA, &PINA, &PORTA, 6},  // A6 34
    {&DDRA, &PINA, &PORTA, 7},  // A7 35
    {&DDRE, &PINE, &PORTE, 4},  // E4 36
    {&DDRE, &PINE, &PORTE, 5},  // E5 37
    {&DDRF, &PINF, &PORTF, 0},  // F0 38
    {&DDRF, &PINF, &PORTF, 1},  // F1 39
    {&DDRF, &PINF, &PORTF, 2},  // F2 40
    {&DDRF, &PINF, &PORTF, 3},  // F3 41
    {&DDRF, &PINF, &PORTF, 4},  // F4 42
    {&DDRF, &PINF, &PORTF, 5},  // F5 43
    {&DDRF, &PINF, &PORTF, 6},  // F6 44
    {&DDRF, &PINF, &PORTF, 7}   // F7 45
  };
  //------------------------------------------------------------------------------
  #else  // CPU type
  #error unknown CPU type
  #endif  // CPU type
  //------------------------------------------------------------------------------
  /** count of pins */
  static const uint8_t digitalPinCount = sizeof(pinMap)/sizeof(pin_map_t);
  //==============================================================================
  /** generate bad pin number error */
  void badPinNumber(void)
    __attribute__((error("Pin number is too large or not a constant")));
  //------------------------------------------------------------------------------
  /** Check for valid pin number
   * @param[in] pin Number of pin to be checked.
   */
  static inline __attribute__((always_inline))
  void badPinCheck(uint8_t pin) {
    if (!__builtin_constant_p(pin) || pin >= digitalPinCount) {
       badPinNumber();
    }
  }
  //------------------------------------------------------------------------------
  /** fast write helper
   * @param[in] address I/O register address
   * @param[in] bit bit number to write
   * @param[in] level value for bit
   */
  static inline __attribute__((always_inline))
  void fastBitWriteSafe(volatile uint8_t* address, uint8_t bit, bool level) {
    uint8_t oldSREG;
    if (address > (uint8_t*)0X5F) {
      oldSREG = SREG;
      cli();
    }
    if (level) {
      *address |= 1 << bit;
    } else {
      *address &= ~(1 << bit);
    }
    if (address > (uint8_t*)0X5F) {
      SREG = oldSREG;
    }
  }
  //------------------------------------------------------------------------------
  /** read pin value
   * @param[in] pin Arduino pin number
   * @return value read
   */
  static inline __attribute__((always_inline))
  bool fastDigitalRead(uint8_t pin) {
    badPinCheck(pin);
    return (*pinMap[pin].pin >> pinMap[pin].bit) & 1;
  }
  //------------------------------------------------------------------------------
  /** toggle a pin
   * @param[in] pin Arduino pin number
   *
   * If the pin is in output mode toggle the pin level.
   * If the pin is in input mode toggle the state of the 20K pullup.
   */
  static inline __attribute__((always_inline))
  void fastDigitalToggle(uint8_t pin) {
    badPinCheck(pin);
      if (pinMap[pin].pin > (uint8_t*)0X5F) {
        // must write bit to high address port
        *pinMap[pin].pin = 1 << pinMap[pin].bit;
      } else {
        // will compile to sbi and PIN register will not be read.
        *pinMap[pin].pin |= 1 << pinMap[pin].bit;
      }
  }
  //------------------------------------------------------------------------------
  /** Set pin value
   * @param[in] pin Arduino pin number
   * @param[in] level value to write
   */
  static inline __attribute__((always_inline))
  void fastDigitalWrite(uint8_t pin, bool level) {
    badPinCheck(pin);
    fastBitWriteSafe(pinMap[pin].port, pinMap[pin].bit, level);
  }
  //------------------------------------------------------------------------------
  /** set pin mode
   * @param[in] pin Arduino pin number
   * @param[in] mode if true set output mode else input mode
   *
   * fastPinMode does not enable or disable the 20K pullup for input mode.
   */
  static inline __attribute__((always_inline))
  void fastPinMode(uint8_t pin, bool mode) {
    badPinCheck(pin);
    fastBitWriteSafe(pinMap[pin].ddr, pinMap[pin].bit, mode);
  }
  
  #endif  // __arm__
  //------------------------------------------------------------------------------
  /** set pin configuration
   * @param[in] pin Arduino pin number
   * @param[in] mode If true set output mode else input mode
   * @param[in] level If mode is output, set level high/low.
   *                  If mode is input, enable or disable the pin's 20K pullup.
   */
  static inline __attribute__((always_inline))
  void fastPinConfig(uint8_t pin, bool mode, bool level) {
    fastPinMode(pin, mode);
    fastDigitalWrite(pin, level);
  }
  //==============================================================================
  /**
   * @class DigitalPin
   * @brief Fast digital port I/O
   */
  template<uint8_t PinNumber>
  class DigitalPin {
   public:
    //----------------------------------------------------------------------------
    /** Constructor */
    DigitalPin() {}
    //----------------------------------------------------------------------------
    /** Constructor
     * @param[in] pinMode if true set output mode else input mode.
     */
    explicit DigitalPin(bool pinMode) {
      mode(pinMode);
    }
    //----------------------------------------------------------------------------
    /** Constructor
     * @param[in] mode If true set output mode else input mode
     * @param[in] level If mode is output, set level high/low.
     *                  If mode is input, enable or disable the pin's 20K pullup.
     */
    DigitalPin(bool mode, bool level) {
      config(mode, level);
    }
    //----------------------------------------------------------------------------
    /** Asignment operator
     * @param[in] value If true set the pin's level high else set the
     *  pin's level low.
     *
     * @return This DigitalPin instance.
     */
    inline DigitalPin & operator = (bool value) __attribute__((always_inline)) {
      write(value);
      return *this;
    }
    //----------------------------------------------------------------------------
    /** Parenthesis operator
     * @return Pin's level
     */
    inline operator bool () const __attribute__((always_inline)) {
      return read();
    }
    //----------------------------------------------------------------------------
    /** set pin configuration
     * @param[in] mode If true set output mode else input mode
     * @param[in] level If mode is output, set level high/low.
     *                  If mode is input, enable or disable the pin's 20K pullup.
     */
    inline __attribute__((always_inline))
    void config(bool mode, bool level) {
      fastPinConfig(PinNumber, mode, level);
    }
    //----------------------------------------------------------------------------
    /**
     * Set pin level high if output mode or enable 20K pullup if input mode.
     */
    inline __attribute__((always_inline))
    void high() {write(true);}
    //----------------------------------------------------------------------------
    /**
     * Set pin level low if output mode or disable 20K pullup if input mode.
     */
    inline __attribute__((always_inline))
    void low() {write(false);}
    //----------------------------------------------------------------------------
    /**
     * Set pin mode
     * @param[in] pinMode if true set output mode else input mode.
     *
     * mode() does not enable or disable the 20K pullup for input mode.
     */
    inline __attribute__((always_inline))
    void mode(bool pinMode) {
      fastPinMode(PinNumber, pinMode);
    }
    //----------------------------------------------------------------------------
    /** @return Pin's level */
    inline __attribute__((always_inline))
    bool read() const {
      return fastDigitalRead(PinNumber);
    }
    //----------------------------------------------------------------------------
    /** toggle a pin
     *
     * If the pin is in output mode toggle the pin's level.
     * If the pin is in input mode toggle the state of the 20K pullup.
     */
    inline __attribute__((always_inline))
    void toggle() {
      fastDigitalToggle(PinNumber);
    }
    //----------------------------------------------------------------------------
    /** Write the pin's level.
     * @param[in] value If true set the pin's level high else set the
     *  pin's level low.
     */
    inline __attribute__((always_inline))
    void write(bool value) {
      fastDigitalWrite(PinNumber, value);
    }
  };
  
  //------------------------------------------------------------------------------
  /** Nop for timing. */
  #define nop asm volatile ("nop\n\t")
  //------------------------------------------------------------------------------
  /** Pin Mode for MISO is input.*/
  const bool MISO_MODE  = false;
  /** Pullups disabled for MISO are disabled. */
  const bool MISO_LEVEL = false;
  /** Pin Mode for MOSI is output.*/
  const bool MOSI_MODE  = true;
  /** Pin Mode for SCK is output. */
  const bool SCK_MODE   = true;
  //------------------------------------------------------------------------------
  /**
   * @class SoftSPI
   * @brief Fast software SPI.
   */
  template<uint8_t MisoPin, uint8_t MosiPin, uint8_t SckPin, uint8_t Mode = 0>
  class SoftSPI {
   public:
    //----------------------------------------------------------------------------
    /** Initialize SoftSPI pins. */
    void begin() {
      fastPinConfig(MisoPin, MISO_MODE, MISO_LEVEL);
      fastPinConfig(MosiPin, MOSI_MODE, !MODE_CPHA(Mode));
      fastPinConfig(SckPin, SCK_MODE, MODE_CPOL(Mode));
    }
    //----------------------------------------------------------------------------
    /** Soft SPI receive byte.
     * @return Data byte received.
     */
    inline __attribute__((always_inline))
    uint8_t receive() {
      uint8_t data = 0;
      receiveBit(7, &data);
      receiveBit(6, &data);
      receiveBit(5, &data);
      receiveBit(4, &data);
      receiveBit(3, &data);
      receiveBit(2, &data);
      receiveBit(1, &data);
      receiveBit(0, &data);
      return data;
    }
    //----------------------------------------------------------------------------
    /** Soft SPI send byte.
     * @param[in] data Data byte to send.
     */
    inline __attribute__((always_inline))
    void send(uint8_t data) {
      sendBit(7, data);
      sendBit(6, data);
      sendBit(5, data);
      sendBit(4, data);
      sendBit(3, data);
      sendBit(2, data);
      sendBit(1, data);
      sendBit(0, data);
    }
    //----------------------------------------------------------------------------
    /** Soft SPI transfer byte.
     * @param[in] txData Data byte to send.
     * @return Data byte received.
     */
    inline __attribute__((always_inline))
    uint8_t transfer(uint8_t txData) {
      uint8_t rxData = 0;
      transferBit(7, &rxData, txData);
      transferBit(6, &rxData, txData);
      transferBit(5, &rxData, txData);
      transferBit(4, &rxData, txData);
      transferBit(3, &rxData, txData);
      transferBit(2, &rxData, txData);
      transferBit(1, &rxData, txData);
      transferBit(0, &rxData, txData);
      return rxData;
    }
  
   private:
    //----------------------------------------------------------------------------
    inline __attribute__((always_inline))
    bool MODE_CPHA(uint8_t mode) {return (mode & 1) != 0;}
    inline __attribute__((always_inline))
    bool MODE_CPOL(uint8_t mode) {return (mode & 2) != 0;}
    inline __attribute__((always_inline))
    void receiveBit(uint8_t bit, uint8_t* data) {
      if (MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, !MODE_CPOL(Mode));
      }
      nop;
      nop;
      fastDigitalWrite(SckPin,
        MODE_CPHA(Mode) ? MODE_CPOL(Mode) : !MODE_CPOL(Mode));
      if (fastDigitalRead(MisoPin)) *data |= 1 << bit;
      if (!MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, MODE_CPOL(Mode));
      }
    }
    //----------------------------------------------------------------------------
    inline __attribute__((always_inline))
    void sendBit(uint8_t bit, uint8_t data) {
      if (MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, !MODE_CPOL(Mode));
      }
      fastDigitalWrite(MosiPin, data & (1 << bit));
      fastDigitalWrite(SckPin,
        MODE_CPHA(Mode) ? MODE_CPOL(Mode) : !MODE_CPOL(Mode));
      nop;
      nop;
      if (!MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, MODE_CPOL(Mode));
      }
    }
    //----------------------------------------------------------------------------
    inline __attribute__((always_inline))
    void transferBit(uint8_t bit, uint8_t* rxData, uint8_t txData) {
      if (MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, !MODE_CPOL(Mode));
      }
      fastDigitalWrite(MosiPin, txData & (1 << bit));
      fastDigitalWrite(SckPin,
        MODE_CPHA(Mode) ? MODE_CPOL(Mode) : !MODE_CPOL(Mode));
      if (fastDigitalRead(MisoPin)) *rxData |= 1 << bit;
      if (!MODE_CPHA(Mode)) {
        fastDigitalWrite(SckPin, MODE_CPOL(Mode));
      }
    }
    //----------------------------------------------------------------------------
  };
  
  
  