Ability to change bit order + SPI support

README.md

@@ -8,3 +8,11 @@ sr.set(1, HIGH)
 Please find the detailed **documentation** at https://timodenk.com/blog/shift-register-arduino-library/.
 
 An **example** sketch can be found in this repository at [/examples/example/example.ino](https://github.com/Simsso/ShiftRegister74HC595/blob/master/examples/example/example.ino).
+
+
+
+New:
+
+to shift data via SPI define `SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY 20000000UL` before you include ShiftRegister74HC595.h 
+
+Arduino UNO uses pin 13 for CLOCK and pin 11 for MOSI (data) - latch pin - configurable.

examples/spi_example/example.ino

@@ -0,0 +1,54 @@
+/*
+  ShiftRegister74HC595 - Library for simplified control of 74HC595 shift registers.
+  Developed and maintained by Timo Denk and contributers, since Nov 2014.
+  Additional information is available at https://timodenk.com/blog/shift-register-arduino-library/
+  Released into the public domain.
+*/
+
+// 20000000UL <- your chip speed. if arduino cant handle that, it will work at max it can. On uno up to 8mhz. 20000000UL means 20Mhz
+// MOSI to shift register DATA pin, SCLK to CLock pin, Latch pin configurable
+#define SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY 20000000UL
+#include <ShiftRegister74HC595.h>
+
+// create a global shift register object
+// parameters: <number of shift registers> (latch pin)
+ShiftRegister74HC595<1> sr(7);
+
+void setup() { 
+}
+
+void loop() {
+
+  // setting all pins at the same time to either HIGH or LOW
+  sr.setAllHigh(); // set all pins HIGH
+  delay(500);
+
+  sr.setAllLow(); // set all pins LOW
+  delay(500); 
+
+
+  // setting single pins
+  for (int i = 0; i < 8; i++) {
+
+    sr.set(i, HIGH); // set single pin HIGH
+    delay(250); 
+  }
+
+
+  // set all pins at once
+  uint8_t pinValues[] = { B10101010 }; 
+  sr.setAll(pinValues); 
+  delay(1000);
+
+
+  // read pin (zero based, i.e. 6th pin)
+  uint8_t stateOfPin5 = sr.get(5);
+  sr.set(6, stateOfPin5);
+
+
+  // set pins without immediate update
+  sr.setNoUpdate(0, HIGH);
+  sr.setNoUpdate(1, LOW);
+  // at this point of time, pin 0 and 1 did not change yet
+  sr.updateRegisters(); // update the pins to the set values
+}

library.properties

@@ -1,5 +1,5 @@
 name=ShiftRegister74HC595
-version=1.3.1
+version=1.3.2
 author=Timo Denk (timodenk.com)
 maintainer=Timo Denk (timodenk.com)
 sentence=Simplifies usage of shift registers, designed for the 74HC595.

src/ShiftRegister74HC595.cpp

@@ -7,3 +7,4 @@
 
 #include <Arduino.h>
 #include "ShiftRegister74HC595.h"
+

src/ShiftRegister74HC595.h

@@ -9,11 +9,19 @@
 
 #include <Arduino.h>
 
+#if defined(SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY)
+#include <SPI.h>
+#endif
+
 template<uint8_t Size>
 class ShiftRegister74HC595 
 {
 public:
+#if !defined(SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY)
     ShiftRegister74HC595(const uint8_t serialDataPin, const uint8_t clockPin, const uint8_t latchPin);
+#else
+    ShiftRegister74HC595(const uint8_t latchPin);
+#endif
 
     void setAll(const uint8_t * digitalValues);
 #ifdef __AVR__
@@ -26,13 +34,22 @@ class ShiftRegister74HC595
     void setAllLow();
     void setAllHigh(); 
     uint8_t get(const uint8_t pin);
+    void order(uint8_t o);
 
 private:
+    #ifdef __AVR__
+    uint8_t bo = MSBFIRST;
+    #else
+    BitOrder bo = MSBFIRST;
+    #endif
     uint8_t _clockPin;
     uint8_t _serialDataPin;
     uint8_t _latchPin;
 
     uint8_t  _digitalValues[Size];
+
+    uint8_t *_port;
+    uint8_t _pinMask;
 };
 
 #include "ShiftRegister74HC595.hpp"

src/ShiftRegister74HC595.hpp

@@ -5,6 +5,9 @@
   Released into the public domain.
 */
 
+
+#if !defined(SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY)
+
 // ShiftRegister74HC595 constructor
 // Size is the number of shiftregisters stacked in serial
 template<uint8_t Size>
@@ -15,6 +18,8 @@ ShiftRegister74HC595<Size>::ShiftRegister74HC595(const uint8_t serialDataPin, co
     _serialDataPin = serialDataPin;
     _latchPin = latchPin;
 
+    bo = MSBFIRST;
+
     // define pins as outputs
     pinMode(clockPin, OUTPUT);
     pinMode(serialDataPin, OUTPUT);
@@ -31,6 +36,40 @@ ShiftRegister74HC595<Size>::ShiftRegister74HC595(const uint8_t serialDataPin, co
     updateRegisters();       // reset shift register
 }
 
+#else
+
+// ShiftRegister74HC595 constructor
+// Size is the number of shiftregisters stacked in serial
+template<uint8_t Size>
+ShiftRegister74HC595<Size>::ShiftRegister74HC595(const uint8_t latchPin)
+{ 
+    _latchPin = latchPin;
+
+#ifdef __AVR__
+    _pinMask = digitalPinToBitMask(latchPin);
+    _port = portOutputRegister(digitalPinToPort(latchPin));
+#endif
+
+    bo = MSBFIRST;
+
+    // define pins as outputs
+    pinMode(latchPin, OUTPUT);
+
+    // set pins low
+    digitalWrite(latchPin, LOW);
+
+    // allocates the specified number of bytes and initializes them to zero
+    memset(_digitalValues, 0, Size * sizeof(uint8_t));
+
+    SPI.begin();
+    SPI.beginTransaction(SPISettings(SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY, bo, SPI_MODE0));
+
+    updateRegisters();       // reset shift register
+}
+
+
+#endif 
+
 // Set all pins of the shift registers at once.
 // digitalVAlues is a uint8_t array where the length is equal to the number of shift registers.
 template<uint8_t Size>
@@ -71,19 +110,38 @@ void ShiftRegister74HC595<Size>::set(const uint8_t pin, const uint8_t value)
     updateRegisters();
 }
 
+
+#if !defined(SHIFT_REGISTER_USES_SPI_WITH_FREQUENCY)
 // Updates the shift register pins to the stored output values.
 // This is the function that actually writes data into the shift registers of the 74HC595.
 template<uint8_t Size>
 void ShiftRegister74HC595<Size>::updateRegisters()
 {
     for (int i = Size - 1; i >= 0; i--) {
-        shiftOut(_serialDataPin, _clockPin, MSBFIRST, _digitalValues[i]);
+        shiftOut(_serialDataPin, _clockPin, bo, _digitalValues[i]);
     }
 
     digitalWrite(_latchPin, HIGH); 
     digitalWrite(_latchPin, LOW); 
 }
-
+#else 
+// Updates the shift register pins to the stored output values.
+// This is the function that actually writes data into the shift registers of the 74HC595.
+template<uint8_t Size>
+void ShiftRegister74HC595<Size>::updateRegisters()
+{
+    for (int i = Size - 1; i >= 0; i--) {
+        SPI.transfer(_digitalValues[i]);
+    }
+    #ifdef __AVR__
+    *_port |= _pinMask;
+    *_port &= ~_pinMask;
+    #else
+    digitalWrite(_latchPin, HIGH); 
+    digitalWrite(_latchPin, LOW); 
+    #endif
+}
+#endif 
 // Equivalent to set(int pin, uint8_t value), except the physical shift register is not updated.
 // Should be used in combination with updateRegisters().
 template<uint8_t Size>
@@ -119,3 +177,9 @@ void ShiftRegister74HC595<Size>::setAllLow()
     }
     updateRegisters();
 }
+
+template<uint8_t Size>
+void ShiftRegister74HC595<Size>::order(uint8_t o)
+{
+    bo = o;
+}