Adding software SPI support (works with ESP32) & added example for rotation

LedMatrix.cpp

@@ -9,6 +9,18 @@ LedMatrix::LedMatrix(byte numberOfDevices, byte slaveSelectPin) {
     myNumberOfDevices = numberOfDevices;
     mySlaveSelectPin = slaveSelectPin;
     cols = new byte[numberOfDevices * 8];
+	rotatedCols = new byte[numberOfDevices * 8];
+}
+
+LedMatrix::LedMatrix(byte numberOfDevices, int8_t sck, int8_t miso, int8_t mosi, byte slaveSelectPin) {
+    myNumberOfDevices = numberOfDevices;
+    mySlaveSelectPin = slaveSelectPin;
+    cols = new byte[numberOfDevices * 8];
+    rotatedCols = new byte[numberOfDevices * 8];
+    customSpiPins = true;
+    _sck = sck;
+    _miso = miso;
+    _mosi = mosi;
 }
 
 /**
@@ -17,8 +29,12 @@ LedMatrix::LedMatrix(byte numberOfDevices, byte slaveSelectPin) {
  */
 void LedMatrix::init() {
     pinMode(mySlaveSelectPin, OUTPUT);
-
-    SPI.begin ();
+
+    if(customSpiPins){
+      SPI.begin ( _sck,  _miso,  _mosi,  mySlaveSelectPin);
+    } else {
+      SPI.begin ();
+    }
     SPI.setDataMode(SPI_MODE0);
     SPI.setClockDivider(SPI_CLOCK_DIV128);
     for(byte device = 0; device < myNumberOfDevices; device++) {
@@ -33,7 +49,7 @@ void LedMatrix::init() {
 void LedMatrix::sendByte (const byte device, const byte reg, const byte data) {
     int offset=device;
     int maxbytes=myNumberOfDevices;
-    
+
     for(int i=0;i<maxbytes;i++) {
         spidata[i] = (byte)0;
         spiregister[i] = (byte)0;
@@ -49,7 +65,7 @@ void LedMatrix::sendByte (const byte device, const byte reg, const byte data) {
         SPI.transfer (spidata[i]);
     }
     digitalWrite (mySlaveSelectPin, HIGH);
-    
+
 }
 
 void LedMatrix::sendByte (const byte reg, const byte data) {
@@ -86,17 +102,19 @@ void LedMatrix::calculateTextAlignmentOffset() {
             myTextAlignmentOffset = - myText.length() * myCharWidth;
             break;
     }
-    
+
 }
 
 void LedMatrix::clear() {
     for (byte col = 0; col < myNumberOfDevices * 8; col++) {
         cols[col] = 0;
     }
-
 }
 
 void LedMatrix::commit() {
+	if ( rotationIsEnabled ) {
+		rotateLeft();
+	}
     for (byte col = 0; col < myNumberOfDevices * 8; col++) {
         sendByte(col / 8, col % 8 + 1, cols[col]);
     }
@@ -163,4 +181,19 @@ void LedMatrix::setColumn(int column, byte value) {
 
 void LedMatrix::setPixel(byte x, byte y) {
     bitWrite(cols[x], y, true);
-}
+}
+
+void LedMatrix::setRotation(bool enabled) {
+	rotationIsEnabled = enabled;
+}
+
+void LedMatrix::rotateLeft() {
+	for (byte deviceNum = 0; deviceNum < myNumberOfDevices; deviceNum++) {
+		for(byte posY = 0; posY < 8; posY++) {
+			for(byte posX = 0; posX < 8; posX++) {
+				bitWrite(rotatedCols[8 * (deviceNum) + posY], posX, bitRead(cols[8 * (deviceNum) + 7-posX], posY));
+			}
+		}
+	}
+	memcpy(cols, rotatedCols, myNumberOfDevices * 8);
+}

LedMatrix.h

@@ -22,114 +22,128 @@
 #define TEXT_ALIGN_RIGHT_END     3 // End of text is just outside the left side of the display
 
 class LedMatrix {
-    
+
 public:
-    
+
     /**
      * Constructor.
      * numberOfDisplays: number of connected devices
      * slaveSelectPin: CS (or SS) pin connected to your ESP8266
      */
     LedMatrix(byte numberOfDisplays, byte slaveSelectPin);
-
+
+    LedMatrix(byte numberOfDevices, int8_t sck, int8_t miso, int8_t mosi, byte slaveSelectPin);
+
     /**
      * Initializes the SPI interface
      */
     void init();
-    
+
     /**
      * Sets the intensity on all devices.
      * intensity: 0-15
      */
     void setIntensity(byte intensity);
-    
+
     /**
      * Sets the width in pixels for one character.
      * Default is 7.
      */
     void setCharWidth(byte charWidth);
-    
+
     /**
      * Sets the text alignment.
      * Default is TEXT_ALIGN_LEFT_END.
      *
      */
     void setTextAlignment(byte textAlignment);
-    
+
     /**
      * Send a byte to a specific device.
      */
     void sendByte (const byte device, const byte reg, const byte data);
-    
+
     /**
      * Send a byte to all devices (convenience method).
      */
     void sendByte (const byte reg, const byte data);
-    
+
     /**
      * Turn on pixel at position (x,y).
      */
     void setPixel(byte x, byte y);
-    
+
     /**
      * Clear the frame buffer.
      */
     void clear();
-    
+
     /**
      * Draw the currently set text at the current offset.
      */
     void drawText();
-    
+
     /**
      * Set the current text.
      */
     void setText(String text);
-    
+
     /**
      * Set the text that will replace the current text after a complete scroll
      * cycle.
      */
     void setNextText(String nextText);
-    
+
     /**
      * Set a specific column with a byte value to the framebuffer.
      */
     void setColumn(int column, byte value);
-    
+
     /**
      * Writes the framebuffer to the displays.
      */
     void commit();
-    
+
     /**
      * Scroll the text to the right.
      */
     void scrollTextRight();
-    
+
     /**
      * Scroll the text to the left.
      */
     void scrollTextLeft();
-    
+
     /**
      * Oscilate the text between the two limits.
      */
     void oscillateText();
-
+
+	/**
+     * Enables 90° rotation for each 8x8 matrix.
+     */
+	void setRotation(bool enabled);
+
 private:
-    byte* cols;
-    byte spiregister[8];
-    byte spidata[8];
-    String myText;
-    String myNextText;
-    int myTextOffset = 1;
-    int myTextAlignmentOffset = 0;
-    int increment = -1;
-    byte myNumberOfDevices = 0;
-    byte mySlaveSelectPin = 0;
-    byte myCharWidth = 7;
-    byte myTextAlignment = 1;
-
+  byte* cols;
+	byte* rotatedCols;
+  byte spiregister[8];
+  byte spidata[8];
+  String myText;
+  String myNextText;
+  int myTextOffset = 1;
+  int myTextAlignmentOffset = 0;
+  int increment = -1;
+  byte myNumberOfDevices = 0;
+  byte mySlaveSelectPin = 0;
+  byte myCharWidth = 7;
+  byte myTextAlignment = 1;
+  bool rotationIsEnabled = false;
+  bool customSpiPins = false;
+  int8_t _sck;
+  int8_t _miso;
+  int8_t _mosi;
+
     void calculateTextAlignmentOffset();
-};
+	void rotateLeft();
+};

README.md

@@ -1,19 +1,20 @@
 # MAX7219LedMatrix
-Library for the ESP8266 on Arduino IDE displaying text on one or multiple MAX7219 8x8 led matrices.
+Library for the ESP8266 & ESP32 on Arduino IDE displaying text on one or multiple MAX7219 8x8 led matrices.
 
 This library displays text and sets specific pixels on one or multiple 8x8 led matrices with a MAX7219 driver chip controlled through the SPI interface.
 These modules are relatively cheep and can be daisy chained which makes it easy to get a led text bar up and running
 You can find modules e.g. with [Banggood](http://www.banggood.com/2Pcs-MAX7219-Dot-Matrix-MCU-LED-Display-Control-Module-Kit-For-Arduino-p-945280.html?p=0P21061109440201501M) (<-affiliate link).
 
-For details about the MAX7219 theory, wiring, schematic, etc. there's a great post by Nick Gammon: http://www.gammon.com.au/forum/?id=11516 
-  
+For details about the MAX7219 theory, wiring, schematic, etc. there's a great post by Nick Gammon: http://www.gammon.com.au/forum/?id=11516
+
 Currently this library supports the following operations:
 
-- set pixels
-- write text with a simple font
-- scroll text left or right 
-- oscillate text between the two ends
-
+- Set pixels
+- Write text with a simple font
+- Scroll text left or right
+- Oscillate text between the two ends
+- Rotate pixels (works with the 4 displays in one module)
+
 You're welcome to [read in my blog](http://blog.squix.ch/2015/04/esp8266arduino-max7219-8x8-led-matrix.html) how this library came about.
 
 ## Example
@@ -25,6 +26,8 @@ You're welcome to [read in my blog](http://blog.squix.ch/2015/04/esp8266arduino-
 #define NUMBER_OF_DEVICES 1
 #define CS_PIN 2
 LedMatrix ledMatrix = LedMatrix(NUMBER_OF_DEVICES, CS_PIN);
+// Can also use software SPI
+// LedMatrix ledMatrix = LedMatrix(NUMBER_OF_DEVICES, CLK_PIN, MISO_PIN, MOSI_PIN, CS_PIN);
 
 void setup() {
   Serial.begin(115200); // For debugging output

examples/RotateTextAndSoftwareSpi/RotateTextAndSoftwareSpi.ino

@@ -0,0 +1,35 @@
+#include <SPI.h>
+#include "LedMatrix.h"
+
+
+#define NUMBER_OF_DEVICES 4
+
+// Wiring that works with ESP32
+#define CS_PIN 15
+#define CLK_PIN 14
+#define MISO_PIN 2 //we do not use this pin just fill to match constructor
+#define MOSI_PIN 12
+
+LedMatrix ledMatrix = LedMatrix(NUMBER_OF_DEVICES, CLK_PIN, MISO_PIN, MOSI_PIN, CS_PIN);
+int x = 0;
+
+void setup() {
+  ledMatrix.init();
+  ledMatrix.setRotation(true);
+
+  ledMatrix.setText("MAX7219 Animation Demo");
+  ledMatrix.setNextText("Second text");
+}
+
+void loop() {
+
+  ledMatrix.clear();
+  ledMatrix.scrollTextLeft();
+  ledMatrix.drawText();
+  ledMatrix.commit();
+  delay(50);
+  x=x+1;
+  if (x == 400) {
+     ledMatrix.setNextText("Third text");
+  }
+}