First Commit

lib/bitBangedSPI/README.md

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+bitBangedSPI
+============
+
+SPI class for Arduino Uno and similar.
+
+For details and documentation see:
+
+http://www.gammon.com.au/forum/?id=10892
+
+In particular: 
+
+http://www.gammon.com.au/forum/?id=10892&reply=6#reply6

lib/bitBangedSPI/bitBangedSPI.cpp

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+/*
+ 
+ Bit-banged SPI class
+ Author: Nick Gammon
+ Date:   24 March 2013
+
+ 
+ PERMISSION TO DISTRIBUTE
+ 
+ Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
+ and associated documentation files (the "Software"), to deal in the Software without restriction, 
+ including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+ and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, 
+ subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in 
+ all copies or substantial portions of the Software.
+ 
+ 
+ LIMITATION OF LIABILITY
+ 
+ The software is provided "as is", without warranty of any kind, express or implied, 
+ including but not limited to the warranties of merchantability, fitness for a particular 
+ purpose and noninfringement. In no event shall the authors or copyright holders be liable 
+ for any claim, damages or other liability, whether in an action of contract, 
+ tort or otherwise, arising from, out of or in connection with the software 
+ or the use or other dealings in the software. 
+
+*/
+
+#include <bitBangedSPI.h>
+
+void bitBangedSPI::begin ()
+  {
+  if (mosi_ != NO_PIN)
+    pinMode (mosi_, OUTPUT);
+  if (miso_ != NO_PIN)
+    pinMode (miso_, INPUT);
+  pinMode (sck_, OUTPUT);
+  }   // end of bitBangedSPI::begin
+  
+  
+// Bit Banged SPI transfer
+byte bitBangedSPI::transfer (byte c)
+{       
+  // loop for each bit  
+  for (byte bit = 0; bit < 8; bit++) 
+    {
+    // set up MOSI on falling edge of previous SCK (sampled on rising edge)
+    if (mosi_ != NO_PIN)
+      {
+      if (c & 0x80)
+          digitalWrite (mosi_, HIGH);
+      else
+          digitalWrite (mosi_, LOW);
+      }
+    // finished with MS bit, get read to receive next bit      
+    c <<= 1;
+ 
+    // read MISO
+    if (miso_ != NO_PIN)
+      c |= digitalRead (miso_) != 0;
+ 
+    // clock high
+    digitalWrite (sck_, HIGH);
+ 
+    // delay between rise and fall of clock
+    delayMicroseconds (delayUs_);
+ 
+    // clock low
+    digitalWrite (sck_, LOW);
+
+    // delay between rise and fall of clock
+    delayMicroseconds (delayUs_);
+    }  // end of for loop, for each bit
+   
+  return c;
+  }  // end of bitBangedSPI::transfer  
+

lib/bitBangedSPI/bitBangedSPI.h

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+/*
+ 
+ Bit-banged SPI class
+ Author: Nick Gammon
+ Date:   24 March 2013
+ 
+ 
+ PERMISSION TO DISTRIBUTE
+ 
+ Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
+ and associated documentation files (the "Software"), to deal in the Software without restriction, 
+ including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+ and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, 
+ subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in 
+ all copies or substantial portions of the Software.
+ 
+ 
+ LIMITATION OF LIABILITY
+ 
+ The software is provided "as is", without warranty of any kind, express or implied, 
+ including but not limited to the warranties of merchantability, fitness for a particular 
+ purpose and noninfringement. In no event shall the authors or copyright holders be liable 
+ for any claim, damages or other liability, whether in an action of contract, 
+ tort or otherwise, arising from, out of or in connection with the software 
+ or the use or other dealings in the software. 
+ 
+ */
+
+#include <Arduino.h>
+
+class bitBangedSPI
+  {
+  // pins
+  const int mosi_;
+  const int miso_;
+  const int sck_;
+  // delay for clock being high
+  unsigned long delayUs_;
+  
+  public:
+    // constructor
+    bitBangedSPI (const int mosi, const int miso, const int sck, const unsigned long delayUs = 4)
+       : mosi_ (mosi), miso_ (miso), sck_ (sck), delayUs_ (delayUs) { }
+    
+    void begin ();
+    byte transfer (byte input);
+
+  enum { NO_PIN = -1 };
+    
+  };  // end of bitBangedSPI