MCP342x.cpp

/* MCP342x library version 1.9.4

Writed by B@tto
Contact : batto@hotmail.fr


  MCP342x.cpp - ADC 18 bits i2c library for Wiring & Arduino
  Copyright (c) 2012 Yann LEFEBVRE.  All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "MCP342x.h"

MCP342x::MCP342x(uint8_t adresse)
{

	_adresse = 0b1101<<3;
	_adresse |= adresse&0b111;

}

MCP342x::~MCP342x()
{

}

void MCP342x::begin(uint8_t setMod)
{

#ifdef ENERGIA
	Wire.setModule(setMod);
#endif

	Wire.begin();

}

uint8_t MCP342x::getAddress()
{
	return _adresse;
}
uint8_t MCP342x::getConfiguration()
{

	Wire.requestFrom(_adresse, _resolution==RESOLUTION_18_BITS?4:3);
	
	uint8_t i=0;

	while(Wire.available()) _buffer[i++] = Wire.read();
	
	return (_buffer[(_resolution==RESOLUTION_18_BITS?3:2)]);
	
}

void MCP342x::setConfiguration(byte channel,int resolution,int mode,int pga)
{

channel&=0b11;
resolution&=0b11;
mode&=0b1;
pga&=0b11;
	
uint8_t cfgbyte=0;
 
_resolution=resolution;
_PGA=pga;
uint32_t divisor = 1;
_LSB = 2048000000/(divisor<<(resolutionConvert[_resolution]-1));

cfgbyte |= (channel & 0x3) << 5;
cfgbyte |= (mode & 0x1) << 4;
cfgbyte |= (resolution & 0x3) << 2;
cfgbyte |= pga & 0x3;

Wire.beginTransmission(_adresse);
Wire.write(cfgbyte);
Wire.endTransmission();

}

void MCP342x::newConversion()
{

	uint8_t cfgbyte=getConfiguration();
	
	Wire.beginTransmission(_adresse);
	Wire.write(cfgbyte|=128);
	Wire.endTransmission();

}

bool MCP342x::isConversionFinished()
{
	
	uint8_t result= !(getConfiguration() & 0b10000000);

	return result;
	
}

void MCP342x::getRawDatas(uint8_t buffer[4])
{
	for(int i=0;i<4;i++) buffer[i]=_buffer[i];
}

int32_t MCP342x::measure()
{

	union resultUnion
	{
		uint8_t asBytes[4];
		int32_t asLong;
	} result;
	
	while(isConversionFinished()==0);
	
	if(_resolution==RESOLUTION_18_BITS)
	{
		result.asBytes[3] = _buffer[0]&0x80?0xFF:0x00;
		result.asBytes[2] = _buffer[0];
		result.asBytes[1] = _buffer[1];
		result.asBytes[0] = _buffer[2];

	} else
	{
		result.asBytes[3] = _buffer[0]&0x80?0xFF:0x00;
		result.asBytes[2] = _buffer[0]&0x80?0xFF:0x00;
		result.asBytes[1] = _buffer[0];
		result.asBytes[0] = _buffer[1];

	}
	
		return (result.asLong * _LSB / PGAConvert[_PGA]);

}