AnalogInput2.cpp

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#include <stdio.h>
#include <unistd.h>

#include "../hubolib.h"

using namespace HuboLib;

/*
Compile and link: 
    g++ AnalogInput2.cpp -L../ -lhubo -lpthread -lrt -o AnalogInput2.out
Run:
    sudo ./AnalogInput2.out
Purpose:
    Using oversampling in order to increase the resolution of an ADC sample value.
*/

int main(void)
{
    // Initialize the library once in your program.
    if (!Initialize())
    {
        printf ("Error: Initialize\n");
        return 1;
    }
    
    // Define channel 0 to be oversampled 4 times (set to 4) all other channels (set to 0) are not read from the ADC.
    unsigned short overSampling[MAX_MCP3x08_CHANNELS] = { 4, 0, 0, 0, 0, 0, 0, 0 };
    Set_MCP3x08_Oversampling (overSampling);
    
    int             channel = 0;
    unsigned long   adcCount; 
    double          volt;
    for (int i=0; i<20; i++)
    {
        // Read channel 0 and output its value.
        if (Get_AI_Channel (channel, adcCount, volt))
        {
            printf ("Channel=%d   ADC count=0x%02lX   Volts=%lf\n", channel, adcCount, volt);
            // Again - you'll see that you're getting the bufferd value a bit later.
            // As it can be seen from the adcCount - the value is about 4 times as high while the
            // voltage is still the same. Oversampled values are just added up, while the voltage
            // is averaged over the 4 samples. 
            // Also you'll notice that the time to get the averaged value has not increased
            // compared to the previouse example where no oversampling was used. This is why all
            // oversampling will be done in one and the same cycle time slice. 
        }
        else 
        {
            printf ("Error: Get_AI_Channel\n");
        }

        usleep(1000);
    }
    
    // Free library resources.
    Uninitialize();
    
    return 0;
}