c lib for mcp3201 circuit

mcp3201.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "mcp3201.h"

mcp3201 device;

void iniciaMCP2301 (volatile unsigned char* port, const char dout_mask, const char clk_mask, const char cs_mask)
{
  device.SPI_PIN_PORT = (unsigned char*) port;
  
  device.DOUT_PIN_MASK = dout_mask;
  device.CLK_PIN_MASK = clk_mask;
  device.CS_PIN_MASK = cs_mask;
  
  setNthBit (device.SPI_PIN_PORT, device.CS_PIN_MASK, 1);
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 0);
 
}

unsigned char buscaMCP2301 ()
{
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 1);
  NOP();
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 0);
  NOP();
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 1);
  NOP();
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 0);
  NOP();
  
  if(!isNthBitSet (device.SPI_PIN_PORT, device.DOUT_PIN_MASK))
    return 1;
  
  return 0;
}

unsigned int readSPIMCP3201 ()
{
  unsigned int retval = 0;
  
  setNthBit (device.SPI_PIN_PORT, device.CS_PIN_MASK, 0);  
  setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 0);

  
  if(buscaMCP2301 ())
    {
      for (int i = 0; i < 12; i++)
        {
          setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 1);
          setNthBit (device.SPI_PIN_PORT, device.CLK_PIN_MASK, 0);
                  
          retval <<=1;
          if(isNthBitSet(device.SPI_PIN_PORT, device.DOUT_PIN_MASK))
            retval |= 1;
        }
    }
  setNthBit (device.SPI_PIN_PORT, device.CS_PIN_MASK, 1);  
  return retval;
}

unsigned char isNthBitSet(unsigned char *c, unsigned char n)
{
  const unsigned char mask[] = {1, 2, 4, 8, 16, 32, 64, 128};
  return (*c & mask[n]);
}

void setNthBit(unsigned char *c, unsigned char n ,unsigned char b)
{ 
  if(b)
    *c |= 1 << n;
  else
    *c &= ~(1 << n);
}

mcp3201.h

/* 
 * File:   mcp3201.h
 * Author: Eduardo
 *
 * Created on 18 de Julho de 2016, 01:40
 */

#ifndef MCP3201_H
#define	MCP3201_H

#ifdef	__cplusplus
extern "C" {
#endif

    typedef struct _mcp3201{
        unsigned char * SPI_PIN_PORT;

        unsigned char DOUT_PIN_MASK;
        unsigned char CLK_PIN_MASK;
        unsigned char CS_PIN_MASK;
    } mcp3201;
    
    void iniciaMCP2301(volatile unsigned char *port, const char dout_mask, const char clk_mask, const char cs_mask);
    unsigned char buscaMCP2301();
    unsigned int readSPIMCP3201();
    unsigned char isNthBitSet(unsigned char *c, unsigned char n);
    void setNthBit(unsigned char *c, unsigned char n ,unsigned char b);

#ifdef	__cplusplus
}
#endif

#endif	/* MCP3201_H */

This is a C library for reading via SPI (bit banging) the MCP3201 ADC integrated circuit.

Designed to be unlinked from hardware. Implementation in 3 lines of code.
The library do not initialize pin direction
Example:
void main(){
unsigned int temp;
/*Function call passing PORT pins and numeration of the respective DOUT, CLK, CS*/
iniciaMCP2301 (&PORTA,0,1,2);
while(true){temp = readSPIMCP3201 ();}
}