#include <Wire.h>
#include <MCP342x.h>
  MCP342x mcp;
 
  long dig0, dig1;
  float u0,u1;
 
void setup(){ 
  Serial.begin(9600);Wire.begin();
}
 
void loop(){
 mcp.setConfig(0,3,0); // in0 - in3 - 0-3 // 12 14 16 18 bit - 0-3 // 1x 2x 4x 8x gain - 0-3
 dig0 = mcp.readWire();
 u0 = dig0 * 2.048 /131071;
 Serial.print(dig0);
 Serial.print("  ");
 Serial.println(u0,6);

 mcp.setConfig(1,3,0); // in0 - in1 - 0-3 // 12 14 16 18 bit - 0-3 // 1x 2x 4x 8x gain - 0-3
 dig1 = mcp.readWire();
 u1 = dig1 * 2.048 /131071;
 Serial.print(dig1);
 Serial.print("  ");
 Serial.println(u1,6);
 delay(1000);
}
 /* 1x = 2.048V; 2x = 1.024V; 4x = 0.512V; 8x = 0.256V
 
 18 bit = 17 bit (dec 131071)  + 1 bit (полярность напряжения) */

#ifndef MCP342x_H
#define MCP342x_H

#define MCP342x_address 0x68 

#include <Arduino.h>

class MCP342x
{
  public:
    MCP342x();
        void setConfig(int in, int bit, int gain); 
        int32_t readWire(void);
    
  private:
    void writeWire(char a);      
};
    
#endif //MCP342x_H

#include <Arduino.h>
#include <Wire.h>
#include "MCP342x.h"

MCP342x::MCP342x(){
    Wire.begin();
}

void MCP342x::setConfig(int in,int bit, int gain){
     switch (in){
        case 0:in = 0b00000000;break;
        case 1:in = 0b00100000;break;
        case 2:in = 0b01000000;break;
        case 3:in = 0b01100000;break;
  }
     switch (bit){
        case 0:bit = 0b00000000;break;
        case 1:bit = 0b00000100;break;
        case 2:bit = 0b00001000;break;
        case 3:bit = 0b00001100;break;
  }
     switch (gain){
        case 0:gain = 0b00000000;break;
        case 1:gain = 0b00000001;break;
        case 2:gain = 0b00000010;break;
        case 3:gain = 0b00000011;break;
  }
        int conf = 0b00010000 + in + bit + gain;
     writeWire(conf);
}


void MCP342x::writeWire(char a){
     Wire.beginTransmission(MCP342x_address);
     Wire.write (a);
     Wire.endTransmission();
}

int32_t MCP342x::readWire(){
        Wire.requestFrom(MCP342x_address,3); //запросить 3 байта данных
   long value = ((Wire.read()<<8) | Wire.read());//упаковка в одну переменную.
        value = ((value<<8)| Wire.read());
   return (int32_t)value;
}