tools/solarmeter/solarmeter.c


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

// data via stdin
// begin = 255 followed by 9 byte  8 mal i + 1 mal u
// u = input * 5/256  // u in V
// i = input / 2.099  // i in mA

#define UFAC 5.0f/256.0f*5.6f/1.89f

int main (int argc, char* argv[])
{
    unsigned char tmp = 0;
    unsigned char buffer[9];
    float pow;
    float pow_sum;
    int i;

    // printf ("blah\n");
    while (read (STDIN_FILENO, &tmp, 1) == 1)
    {
        if (tmp == 255)
        {
            if (read (STDIN_FILENO, &buffer, 9) != 9)
            {
                printf ("read error\n");
                return 0;
            }
            printf ("%5.2fV", buffer[8] * UFAC);
            pow_sum = 0.0f;
            for (i = 0; i<8; i++)
            {
                pow = (buffer[i] / 2.099f) * (buffer[8] * UFAC);
                printf (" %6.2fmW", pow);
                pow_sum += pow;
            }
            printf (" %6.2fmW", pow_sum);
            printf ("\r");
        }
    }
    printf ("\n");
    return 0;
}