Fix frequency measurement simulation

controller/fw/tools/freq_meas_test.c

@@ -1,4 +1,6 @@
 
+#include <stdint.h>
+#include <math.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
@@ -13,7 +15,7 @@
 void print_usage(void);
 
 void print_usage() {
-    fprintf(stderr, "Usage: freq_meas_test [test_data.bin]");
+    fprintf(stderr, "Usage: freq_meas_test [test_data.bin]\n");
 }
 
 int main(int argc, char **argv) {
@@ -46,6 +48,7 @@ int main(int argc, char **argv) {
         return 2;
     }
 
+    fprintf(stderr, "Reading %zd samples test data...", st.st_size/sizeof(float));
     size_t nread = 0;
     while (nread < st.st_size) {
         ssize_t rc = read(fd, buf, st.st_size - nread);
@@ -54,41 +57,48 @@ int main(int argc, char **argv) {
             continue;
 
         if (rc < 0) {
-            fprintf(stderr, "Error reading test data: %s\n", strerror(errno));
+            fprintf(stderr, "\nError reading test data: %s\n", strerror(errno));
             return 2;
         }
         
         if (rc == 0) {
-            fprintf(stderr, "Error reading test data: Unexpected end of file\n");
+            fprintf(stderr, "\nError reading test data: Unexpected end of file\n");
             return 2;
         }
 
         nread += rc;
     }
+    fprintf(stderr, " done.\n");
 
     size_t n_samples = st.st_size / sizeof(float);
     float *buf_f = (float *)buf;
 
-    uint16_t *sim_adc_buf = calloc(sizeof(uint16_t), n_samples);
+    int16_t *sim_adc_buf = calloc(sizeof(int16_t), n_samples);
     if (!sim_adc_buf) {
         fprintf(stderr, "Error allocating memory\n");
         return 2;
     }
 
+    fprintf(stderr, "Converting and truncating test data...");
     for (size_t i=0; i<n_samples; i++)
-        sim_adc_buf[i] = 2048 + buf_f[i] * 2047;
+        /* Note on scaling: We can't simply scale by 0x8000 (1/2 full range) here. Our test data is nominally 1Vp-p but
+         * certain tests such as the interharmonics one can have some samples exceeding that range. */
+        sim_adc_buf[i] = buf_f[i] * (0x4000-1);
+    fprintf(stderr, " done.\n");
 
-    for (size_t i=0; i<n_samples; i+=FMEAS_FFT_LEN) {
+    fprintf(stderr, "Starting simulation.\n");
 
-        float out;
-        int rc = adc_buf_measure_freq(sim_adc_buf + i, &out);
-        if (rc) {
-            fprintf(stderr, "Simulation error in iteration %zd at position %zd: %d\n", i/FMEAS_FFT_LEN, i, rc);
-            return 3;
-        }
+    size_t iterations = (n_samples-FMEAS_FFT_LEN)/(FMEAS_FFT_LEN/2);
+    for (size_t i=0; i<iterations; i++) {
 
-        printf("%09zd %015f\n", i, out);
+        fprintf(stderr, "Iteration %zd/%zd\n", i, iterations);
+        float res = NAN;
+        int rc = adc_buf_measure_freq(sim_adc_buf + i*(FMEAS_FFT_LEN/2), &res);
+        if (rc)
+            printf("ERROR: Simulation error in iteration %zd at position %zd: %d\n", i, i*(FMEAS_FFT_LEN/2), rc);
+
+        printf("%09zd %12f\n", i, res);
     }
-
+    
     return 0;
 }

controller/fw/tools/freq_meas_test_runner.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+
+import os
+from os import path
+import subprocess
+import json
+
+import numpy as np
+np.set_printoptions(linewidth=240)
+
+
+if __name__ == '__main__':
+    import argparse
+    parser = argparse.ArgumentParser()
+    parser.add_argument(metavar='test_data_directory', dest='dir', help='Directory with test data .bin files')
+    default_binary = path.abspath(path.join(path.dirname(__file__), '../build/tools/freq_meas_test'))
+    parser.add_argument(metavar='test_binary', dest='binary', nargs='?', default=default_binary)
+    parser.add_argument('-d', '--dump', help='Write raw measurements to JSON file')
+    args = parser.parse_args()
+
+    bin_files = [ path.join(args.dir, d) for d in os.listdir(args.dir) if d.lower().endswith('.bin') ]
+
+    savedata = {}
+    for p in bin_files:
+        output = subprocess.check_output([args.binary, p], stderr=subprocess.DEVNULL)
+        measurements = np.array([ float(value) for _offset, value in [ line.split() for line in output.splitlines() ] ])
+        savedata[p] = list(measurements)
+
+        # Cut off first and last sample for mean and RMS calculations as these show boundary effects.
+        measurements = measurements[1:-1]
+        mean = np.mean(measurements)
+        rms = np.sqrt(np.mean(np.square(measurements - mean)))
+
+        print(f'{path.basename(p):<60}:    mean={mean:<8.4f}Hz rms={rms*1000:.3f}mHz')
+
+    if args.dump:
+        with open(args.dump, 'w') as f:
+            json.dump(savedata, f)
+