K8055 & PT1000

// Tested with pelles c

#include <stdio.h>
#include <windows.h>
#include <process.h>

typedef void(CALLBACK* t_func)(int );
typedef void(CALLBACK* t_func0)();
typedef int(CALLBACK* t_func1)();
typedef void(CALLBACK* t_func2)(int *, int *);
typedef void(CALLBACK* t_func3)(int , int );
typedef int(CALLBACK* t_func4)(int );
typedef boolean(CALLBACK* t_func5)(int );

t_func4 OpenDevice;
t_func0 CloseDevice;
t_func0 Version_;
t_func4 ReadAnalogChannel;
t_func2 ReadAllAnalog;
t_func3 OutputAnalogChannel;
t_func3 OutputAllAnalog;
t_func ClearAnalogChannel;
t_func0 ClearAllAnalog;
t_func SetAnalogChannel;
t_func0 SetAllAnalog;
t_func WriteAllDigital;
t_func ClearDigitalChannel;
t_func0 ClearAllDigital;
t_func SetDigitalChannel;
t_func0 SetAllDigital;
t_func5 ReadDigitalChannel;
t_func1 ReadAllDigital;
int init(void);
float GetPt1000Temperature(float);
int analog_cnt = -1;

// change buffer size here when needed
#define buffer_size 64
float analog_buffer[buffer_size] = {0};


void __cdecl analog_reader (void* d){
    int a1, a2;
    while(1){
        analog_cnt++;
        if(analog_cnt == buffer_size) analog_cnt = 0;
        ReadAllAnalog(&a1, &a2);
        analog_buffer[analog_cnt] = (a1 + a2) / 2;
        // maybe add a call to Sleep here...
    }
}

float get_analog_value(void){
    float rval = 0;
    for(int i = 0; i < buffer_size; i++) rval += analog_buffer[i];
    return rval / buffer_size;
}

int main(int argc, char *argv[])
{
    if(init() != 0) return -1;
    if(OpenDevice(0) != 0) return -2;

    // Start Worker
    _beginthread(&analog_reader,0,0);

    // Make sure the analog_buffer is filled bevor using
    Sleep(2000);

    // set v_in in Volt and r1 in Ohm
    float v_in = 5;
    float r1 = 470;

    while(1){

        // Calculate Vout
        float v_out = v_in / 255 * get_analog_value();
        // Calculate R2
        float r2 = r1 / ((v_in/v_out) -1) ;
        // Translate R2 to Temperature [°C]
        float t = GetPt1000Temperature(r2);

        // Print temperature, rounded to 1 digit after the decimal point
        printf("%.1f\n",t);
        Sleep(1000);
    }

}

int init()
{
    HINSTANCE hDLL = LoadLibrary("k8055d");
    if (hDLL != NULL)
    {
        OpenDevice = (t_func4) GetProcAddress(hDLL, "OpenDevice");
        if (!OpenDevice)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        CloseDevice = (t_func0) GetProcAddress(hDLL, "CloseDevice");
        if (!CloseDevice)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ReadAnalogChannel = (t_func4) GetProcAddress(hDLL, "ReadAnalogChannel");
        if (!ReadAnalogChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ReadAllAnalog = (t_func2) GetProcAddress(hDLL, "ReadAllAnalog");
        if (!ReadAllAnalog)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        OutputAnalogChannel = (t_func3) GetProcAddress(hDLL, "OutputAnalogChannel");
        if (!OutputAnalogChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        OutputAllAnalog = (t_func3) GetProcAddress(hDLL, "OutputAllAnalog");
        if (!OutputAllAnalog)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ClearAnalogChannel = (t_func) GetProcAddress(hDLL, "ClearAnalogChannel");
        if (!ClearAnalogChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ClearAllAnalog = (t_func0) GetProcAddress(hDLL, "ClearAllAnalog");
        if (!ClearAllAnalog)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        SetAnalogChannel = (t_func) GetProcAddress(hDLL, "SetAnalogChannel");
        if (!SetAnalogChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        SetAllAnalog = (t_func0) GetProcAddress(hDLL, "SetAllAnalog");
        if (!SetAllAnalog)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        WriteAllDigital = (t_func) GetProcAddress(hDLL, "WriteAllDigital");
        if (!WriteAllDigital)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ClearDigitalChannel = (t_func) GetProcAddress(hDLL, "ClearDigitalChannel");
        if (!ClearDigitalChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ClearAllDigital = (t_func0) GetProcAddress(hDLL, "ClearAllDigital");
        if (!ClearAllDigital)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        SetDigitalChannel = (t_func) GetProcAddress(hDLL, "SetDigitalChannel");
        if (!SetDigitalChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        SetAllDigital = (t_func0) GetProcAddress(hDLL, "SetAllDigital");
        if (!SetAllDigital)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ReadDigitalChannel = (t_func5) GetProcAddress(hDLL, "ReadDigitalChannel");
        if (!ReadDigitalChannel)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        ReadAllDigital = (t_func1) GetProcAddress(hDLL, "ReadAllDigital");
        if (!ReadAllDigital)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        Version_ = (t_func0) GetProcAddress(hDLL, "Version");
        if (!Version_)
        {                       // handle the error
            FreeLibrary(hDLL);
            return -2;
        }
        return 0;               // ok
    }
    return -1;                  // error load DLL
}

// from here: http://en.wikipedia.org/wiki/Resistance_thermometer

float GetPt100Temperature(float r)
{
    float const Pt100[] = {  80.31,   82.29,  84.27,  86.25,  88.22,  90.19,  92.16,  94.12,  96.09,  98.04,
                                100.0,    101.95, 103.9,  105.85, 107.79, 109.73, 111.67, 113.61, 115.54, 117.47,
                                119.4,  121.32, 123.24, 125.16, 127.07, 128.98, 130.89, 132.8,  134.7,  136.6,
                                138.5,  140.39, 142.29, 157.31, 175.84, 195.84};
    int t = -50, i, dt = 0;
    if (r > Pt100[i = 0])
      while (250 > t) {
        dt = (t < 110) ? 5 : (t > 110) ? 50 : 40;
        if (r < Pt100[++i])
          return t + (r - Pt100[i-1]) * dt / (Pt100[i] - Pt100[i-1]);
        t += dt;
      };

    return t;
}

float GetPt1000Temperature(float r)
{
    return GetPt100Temperature(r / 10);
}