root/branches/follower/libw5100/src/libw5100/spi.cpp

/*

   SPI Configuration

   Author: 

      Philip Lindsay <follower@rancidbacon.com>

   License:

      Copyright 2007-2008 // LGPL


   TODO: Enable multiple SPI devices to be controlled.

*/

#include "spi.h"

SpiConfiguration::SpiConfiguration() {
  //  begin();
}

void SpiConfiguration::begin(void) {
  /*

     Configure pins and registers required for SPI communication.
  
  */
  
  //   Configure I/O pins
  pinMode(PIN_DATA_OUT, OUTPUT);
  pinMode(PIN_DATA_IN, INPUT);
  pinMode(PIN_SPI_CLOCK, OUTPUT);
  pinMode(PIN_SLAVE_SELECT, OUTPUT);
  
  digitalWrite(PIN_SLAVE_SELECT, HIGH); // Disable slave
  
  /*
     Configure SPI Control Register (SPCR) (All values initially 0)
      Bit  Description
        7  SPI Interrupt Enable    -- disable  (SPIE --> 0)
        6  SPI Enable              -- enable   (SPE  --> 1)
        5  Data Order              -- MSB 1st  (DORD --> 0) (Slave specific)
        4  Master/Slave Select     -- master   (MSTR --> 1)
        3  Clock Polarity          --          (CPOL --> 0) (Slave specific) ("Mode")
        2  Clock Phase             --          (CPHA --> 0) (Slave specific)
        1  SPI Clock Rate Select 1 -- }        (SPR1 --> 0) 
        0  SPI Clock Rate Select 0 -- } fOSC/4 (SPR0 --> 0) ("Fastest" but see SPI2X in SPSR)
  */
  SPCR = (1<<SPE)| (1<<MSTR);

  // Clear previous data and status (TODO: Determine if necessary/better way.)
  // (Based on Arduino Playground SPI example.)
  byte dummy;
  dummy = SPSR;
  dummy = SPDR;
  delay(10);
  
}


/*
 Instantiate a 'SPI' object to be used in a manner consistent with
 the way the Arduino environment handles serial configuration with the
 'Serial'/'HardwareSerial' object/class combination.
*/

SpiConfiguration SPI = SpiConfiguration();