usrp/: new tools to run, evaluate, and plot a full frequency scan

- usrp/fscan: perform a frequency scan in my test setup
- usrp/evscan: determine the frequency-dependent signal strength from a
  frequency scan
- usrp/plscan: plot one or more data sets produced by evscan

usrp/evscan

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+usage()
+{
+    echo "usage: $0 base-dir" 1>&2
+    exit 1
+}
+
+
+[ -d "$1" ] || usage
+[ "$2" ] && usage
+
+for f in "$1"/24*; do
+    echo -n `basename "$f"` ''
+    for n in "$f"/data*; do
+	./fft -s 100 0 20 50 <"$n" || echo "fft failed for $n" 1>&1
+    done | ./range -v 2
+done

usrp/fscan

@@ -0,0 +1,36 @@
+#!/bin/sh
+
+
+usage()
+{
+    echo "usage: $0 out-dir [tx-power]" 1>&2
+    exit 1
+}
+
+
+[ "$1" ] || usage
+[ "$3" ] && usage
+mkdir "$1" || exit
+pwr=${2:-2.6}
+
+unset DISPLAY
+
+if [ "${1#/}" = "$1" ]; then
+    abs=`pwd`/$1
+else
+    abs=$1
+fi
+
+for a in 0 1 2 3 4 5 6 7 8 9; do
+    for b in 0 1 2 3 4 5 6 7 8 9; do
+	f=2405
+	while [ $f -le 2480 ]; do
+	    echo -e $a$b $f MHz '\r'
+	    mkdir -p "$1/$f"
+	    atrf-txrx -f $f -p $pwr -T +0.5 \
+	      "ssh ws usrp2_rx_cfile.py -d 16 -f $f.5M -g 46 -N 1124 \
+	         $abs/$f/data$a$b"
+	    f=`expr $f + 5`
+	done
+    done
+done

usrp/plscan

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+usage()
+{
+    echo "usage: $0 [-o pngfile] file ..." 1>&2
+    exit 1
+}
+
+
+if [ "X$1" = X-o ]; then
+    out=$2
+    shift 2
+fi
+[ "$1" ] || usage
+[ "${1#-}" = "$1" ] || usage
+
+gnuplot -persist <<EOF
+`[ "$out" ] && ( echo set term png\;; echo set output \'$out\'; )`
+set xlabel "MHz"
+set ylabel "dB"
+set xrange [2402:2483]
+set yrange [-35:-25]
+set title "Received signal strength"
+set data style errorlines
+plot \
+  `for n in $@; do
+     echo -n $comma \'$n\' title \'\`echo "$n" | sed "s/\..*//"\`\'
+     comma=,
+   done`
+EOF