SPI/SPI.cpp

#include "SPI.h"

extern "C" {
  #include <inttypes.h>
  #include "WConstants.h"
}



SPI::SPI(unsigned char timeout, 
         unsigned char mosi_pin, 
         unsigned char miso_pin, 
         unsigned char sck_pin) {
  _timeout = timeout;
  _mosi_pin = mosi_pin;
  _miso_pin = miso_pin;
  _sck_pin = sck_pin;
};


void SPI::init(unsigned char spcr, unsigned char spsr) {
  digitalWrite(_mosi_pin, LOW);
  digitalWrite(_sck_pin, LOW);
  pinMode(_mosi_pin, OUTPUT);
  pinMode(_sck_pin,  OUTPUT);
  pinMode(_miso_pin, INPUT);
  SPCR = spcr;
  SPSR = spsr;
};



char SPI::write(unsigned char *data, unsigned char num_chars) {
  unsigned char *p;
  unsigned char i = 0;
  unsigned char count = 0;
  p = data;
  for ( i = 0; i < num_chars; i++) {
    SPDR = *p++;   
    count = 0;
    while (1) {
      if (SPSR & (1<<SPIF)) break; // transmission complete
      delay(1);
      //      if (++count == _timeout) return(-1);
      if (++count == 10) return(-1);
    }
  }
  return(0);
};

char SPI::read(unsigned char *data, unsigned char max_num_chars) {
  return(-1);
};