Add software spi support for max6675

Marlin/softspi.h

@@ -0,0 +1,770 @@
+//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__)
+
+#ifdef 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));
+    }
+  }
+  //----------------------------------------------------------------------------
+};
+
+

Marlin/spi.h

@@ -0,0 +1,68 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef __SPI_H__
+#define __SPI_H__
+
+#include <stdint.h>
+#include "softspi.h"
+
+template<uint8_t MisoPin, uint8_t MosiPin, uint8_t SckPin>
+class Spi {
+  static SoftSPI<MisoPin, MosiPin, SckPin> softSpi;
+  public:
+    inline __attribute__((always_inline))
+    static void init() {
+        softSpi.begin();
+    }
+    inline __attribute__((always_inline))
+    static void send(uint8_t data) {
+        softSpi.send(data);
+    }
+    inline __attribute__((always_inline))
+    static uint8_t receive() {
+        return softSpi.receive();
+    }
+};
+
+
+//hardware spi
+template<>
+class Spi<MISO_PIN, MOSI_PIN, SCK_PIN> {
+  public:
+    inline __attribute__((always_inline))
+    static void init() {
+        OUT_WRITE(SCK_PIN, LOW);
+        OUT_WRITE(MOSI_PIN, HIGH);
+        SET_INPUT(MISO_PIN);
+        WRITE(MISO_PIN, HIGH);
+    }
+    inline __attribute__((always_inline))
+    static uint8_t receive() {
+      SPDR = 0;
+      for (;!TEST(SPSR, SPIF););
+      return SPDR;
+    }
+
+};
+
+#endif

Marlin/temperature.cpp

@@ -31,6 +31,7 @@
 #include "temperature.h"
 #include "thermistortables.h"
 #include "language.h"
+#include "spi.h"
 #if ENABLED(BABYSTEPPING)
   #include "stepper.h"
 #endif
@@ -942,6 +943,15 @@ void Temperature::updateTemperaturesFromRawValues() {
 
 #endif
 
+#if ENABLED(HEATER_0_USES_MAX6675)
+  #ifndef MAX6675_SCK_PIN
+    #define MAX6675_SCK_PIN SCK_PIN
+  #endif
+  #ifndef MAX6675_DO_PIN
+    #define MAX6675_DO_PIN MISO_PIN
+  #endif
+  Spi<MAX6675_DO_PIN, MOSI_PIN, MAX6675_SCK_PIN> max6675_spi;
+#endif
 
 /**
  * Initialize the temperature manager
@@ -1007,11 +1017,13 @@ void Temperature::init() {
     OUT_WRITE(SCK_PIN, LOW);
     OUT_WRITE(MOSI_PIN, HIGH);
     SET_INPUT_PULLUP(MISO_PIN);
-    OUT_WRITE(SS_PIN, HIGH);
 
+    max6675_spi.init();
+
+    OUT_WRITE(SS_PIN, HIGH);
     OUT_WRITE(MAX6675_SS, HIGH);
 
-  #endif //HEATER_0_USES_MAX6675
+  #endif // HEATER_0_USES_MAX6675
 
   #ifdef DIDR2
     #define ANALOG_SELECT(pin) do{ if (pin < 8) SBI(DIDR0, pin); else SBI(DIDR2, pin - 8); }while(0)
@@ -1356,9 +1368,7 @@ void Temperature::disable_all_heaters() {
     // Read a big-endian temperature value
     max6675_temp = 0;
     for (uint8_t i = sizeof(max6675_temp); i--;) {
-      SPDR = 0;
-      for (;!TEST(SPSR, SPIF););
-      max6675_temp |= SPDR;
+      max6675_temp |= max6675_spi.receive();
       if (i > 0) max6675_temp <<= 8; // shift left if not the last byte
     }