usrp/: a set of utilities for testing board performance with an USRP2

- usrp/d.c: reduce the number of data points in a file produced by
  usrp2_rx_cfile.py and print them as text suitable for gnuplot
- usrp/p.c: determine the peak amplitude in a series of transmissions,
  filtering noise and artefacts at the beginning of the data file
- usrp/step: step through all channels and measure TX power (for antenna
  tuning)
- usrp/Makefile: built "p" and "d"

usrp/Makefile

@@ -0,0 +1,4 @@
+CFLAGS=-Wall -O9
+LDFLAGS=-lm
+
+all:	p d

usrp/d.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <math.h>
+
+
+#define N	100
+
+
+int main(int argc, char **argv)
+{
+	float c[2];
+	int n = 0;
+	float sum = 0;
+	size_t s;
+
+
+	while (1) {
+		s = fread(c, sizeof(c), 1, stdin);
+		if (!s) {
+			if (!ferror(stdin))
+				break;
+			if (s < 0) {
+				perror("read");
+				return 1;
+			}
+		}
+		sum += hypot(c[0], c[1]);
+		if (n++ % N)
+			continue;
+		printf("%f\n", sum/N);
+		sum = 0;
+	}
+	return 0;
+}

usrp/p.c

@@ -0,0 +1,66 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <sys/types.h>
+
+
+#define PERC	0.9
+#define	SKIP	1000000
+
+
+static int comp(const void *_a, const void *_b)
+{
+	float a = *(const float *) _a;
+	float b = *(const float *) _b;
+
+	return a < b ? -1 : a > b;
+}
+
+
+int main(int argc, char **argv)
+{
+	float max = 0;
+	float c[2], a;
+	float *rec = NULL;
+	int e = 0, n = 0, skip = SKIP;
+
+	while (1) {
+		size_t s;
+
+		s = fread(c, sizeof(c), 1, stdin);
+		if (!s) {
+			if (!ferror(stdin))
+				break;
+			if (s < 0) {
+				perror("read");
+				return 1;
+			}
+		}
+		if (skip) {
+			skip--;
+			continue;
+		}
+		a = hypotf(c[0], c[1]);
+		if (a > max)
+			max = a;
+		if (e <= n) {
+			e = e ? e*2 : 10000;
+			rec = realloc(rec, e*sizeof(float));
+			if (!rec) {
+				perror("realloc");
+				exit(1);
+			}
+		}
+		rec[n] = a;
+		n++;
+	}
+	qsort(rec, n, sizeof(float), comp);
+	printf("%f %f\n", max, rec[(int) (PERC*n)]);
+#if 0
+int i;
+
+	for (i = 0; i < n; i += 1000)
+		printf("%f %f\n", (double) i/n, rec[i]);
+#endif
+	return 0;
+}

usrp/step

@@ -0,0 +1,36 @@
+#!/bin/sh -x
+
+CH_FIRST=11
+CH_LAST=26
+RUNS=10
+
+m10=0123456789
+m20=$m10$m10
+MSG=$m20$m20$m20$m20$m20
+
+
+mhz()
+{
+    expr 2405 + 5 \* \( $1 - 11 \)
+}
+
+rm -f out
+run=0
+while [ $run -lt $RUNS ]; do
+    c=$CH_FIRST
+    while [ $c -le $CH_LAST ]; do
+	echo "Run $run, ch $c (`mhz $c` MHz)" 1>&2
+        mhz $c | tr '\n' ' ' >>out
+	( ssh ben ./atspi-txrx -c $c -p 4 $MSG 1500; echo DONE 1>&2; ) &
+	sleep 3
+	usrp2_rx_cfile.py -d 4 -f `mhz $c`M -g 40 -N 100M tmp
+	sync
+	./p <tmp >>out
+	rm -f tmp
+	sync
+	sleep 2
+	c=`expr $c + 1`
+    done
+    run=`expr $run + 1`
+    echo >>out
+done