/* connect the DAC to to ADC and call this with adc <dac> <adc> to get data
   MUST be linked with the Labmaster! eg
   gcc -Wall -O3 -ansi -pedantic -lm -llabmaster -o adc adc.c */

#include <stdio.h>     /* [f]printf */
#include <stdlib.h>    /* sscanf */
#include <math.h>      /* sqrt */
#include <labmaster.h> /* labmaster calls */
#include "dac.h"

const static int dacStep = 16;
const static int iterations = 256;

int main(int argc, char **argv) {
  int dac, adc, dacIn, iter;
  double dacOut, adcOut, adcErr, adcUnc, sum, sumSq;

  /* initialize arguments */
  if(argc < 3) { fprintf(stderr, "Usage: adc <dac> <adc>\n"); return 1; }
  if(sscanf(argv[1], "%d", &dac) != 1) {
    fprintf(stderr, "Ca'n't parse DAC.\n");
    return 1;
  }
  if(dac < 0 || dac > 1) { fprintf(stderr, "DAC out-of-bounds.\n"); return 1; }
  if(sscanf(argv[2], "%d", &adc) != 1) {
    fprintf(stderr, "Ca'n't parse ADC.\n");
    return 1;
  }
  if(adc < 0 || adc > 3) { fprintf(stderr, "ADC out-of-bounds.\n"); return 1; }

  /* "This step is critical," OK */
  labmaster_initialize();

  /* connect DAC to ADC */
  for(dacIn = -2048; dacIn < 2048; dacIn += dacStep) {
    /* dac output */
    out_dac(dac, dacIn);
    /* dac translated to volts */
    dacOut = a[dac] + (b[dac] * dacIn);
    /* adc out, average, error */
    for(iter = 0, sum = 0, sumSq = 0; iter < iterations; iter++) {
      adcOut = in_adc(adc);
      sum += adcOut;
      sumSq += adcOut * adcOut;
    }
    adcOut = sum / iterations;
    adcErr = sqrt(sumSq / iterations - adcOut * adcOut);
    adcUnc = adcErr / sqrt(iterations);

    /* points were getting saturated, hence if() */
    if(adcUnc) printf("%g %g %g\n", dacOut, adcOut, adcUnc);
  }

  /* I assume this step is critical too */
  labmaster_terminate();

  return 0;
}