usrp/sps/: spectrum scan utilities (work in progress)

- collect: set up a test transmission at each available frequency, then
  then record the signal seen by the USRP2
- norm: extract parameters necessary for normalization
- viz: visualize the spectrum with gnuplot
- row: generate rows of spectra with "viz"

usrp/sps/collect

@@ -0,0 +1,14 @@
+#!/bin/sh
+if ! [ "$1" ]; then
+	echo "usage: $0 prefix" 2>&1
+	exit 1
+fi
+f=2405
+while [ $f -le 2480 ]; do
+	f1=`expr $f + 1`
+	atrf-txrx -f $f -p 4 -T -0.5 \
+	    'sleep 1; usrp2_rx_cfile.py -d 16 -g 46 -f '$f'M -N 1M '$1-$f
+	atrf-txrx -f $f -p 4 -T +0.5 \
+	    'sleep 1; usrp2_rx_cfile.py -d 16 -g 46 -f '$f1'M -N 1M '$1-$f1
+	f=`expr $f + 5`
+done

usrp/sps/norm

@@ -0,0 +1,10 @@
+#!/usr/bin/perl
+
+for ($n = 0; <>; $n++) {
+	if ($_ > $ym || !defined $ym) {
+		$xm = $n;
+		chop($ym = $_);
+	}
+}
+
+print "$xm $ym $n\n";

usrp/sps/row

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+export GDFONTPATH
+GDFONTPATH=$GDFONTPATH:/usr/share/fonts/truetype/ttf-liberation/
+
+if ! [ "$1" ]; then
+	echo "usage: $0 prefix" 2>&1
+	exit 1
+fi
+
+prefix=$1
+
+echo "<TR><TH>$prefix"
+f=2405
+while [ $f -le 2480 ]; do
+	echo "<TD align="center">$f MHz"
+	f=`expr $f + 5`
+done
+
+echo "<TR><TD align="right">-0.5 MHz"
+f=2405
+while [ $f -le 2480 ]; do
+	./viz -f LiberationSans-Bold -p $prefix-$f.png $prefix $f
+	convert -resize '15%' $prefix-$f.png $prefix-$f-small.png
+	echo "<TD><A href=\"$prefix-$f.png\"><IMG src=\"$prefix-$f-small.png\"></A>"
+	f=`expr $f + 5`
+done
+
+echo "<TR><TD align="right">+0.5 MHz"
+f=2405
+while [ $f -le 2480 ]; do
+	f1=`expr $f + 1`
+	./viz -f LiberationSans-Bold -p $prefix-$f1.png $prefix $f1
+	convert -resize '15%' $prefix-$f1.png $prefix-$f1-small.png
+	echo "<TD><A href=\"$prefix-$f1.png\"><IMG src=\"$prefix-$f1-small.png\"></A>"
+	f=`expr $f + 5`
+done

usrp/sps/viz

@@ -0,0 +1,69 @@
+#!/bin/sh
+
+usage()
+{
+	echo "usage: $0 [-f font] prefix frequency" 1>&2
+	exit 1
+}
+
+
+font=
+term=
+output=
+while true; do
+	case "$1" in
+	-f)	[ "$2" ] || usage
+		shift
+		font=$1
+		shift;;
+	-p)	[ "$2" ] || usage
+		shift
+		term="set term png"
+		output="set output \"$1\""
+		shift;;
+	*)
+		break;;
+	esac
+done
+
+[ "$2" ] || usage
+[ "$3" ] && usage
+
+prefix=$1
+f=$2
+
+../fft -s 100 -d -w hamming 100 <./$prefix-$f >_tmp
+set `./norm _tmp`
+
+xm=$1.0		# sample number of y peak
+ym=$2		# magnitude of y peak
+n=$3		# total number of samples
+span=6.25	# ADC sample rate in MHz / decimation (100 MHz/16)
+
+gnuplot -persist <<EOF
+$term
+$output
+
+set label "$prefix" at graph 0.03, graph 0.93 font "$font,22"
+set label sprintf("+%.1f dB", $ym) at graph 0.03, graph 0.82 font "$font,18"
+
+set label sprintf("%.1f MHz", $f-0.5) \
+  at graph 0.97, graph 0.93 right font "$font,22"
+set label sprintf("+%.1f ppm", (($xm/$n-0.5)*$span+0.5)/($f-0.5)*1000000) \
+  at graph 0.97, graph 0.82 right font "$font,18"
+
+set xrange [-2.5:2.5]
+set yrange [-70:0]
+
+set mxtics 10
+set mytics 2
+set grid
+
+set xlabel "MHz from nominal frequency of test wave"
+
+set style fill solid 1
+plot "_tmp" using ((\$0/$n-0.5)*$span+0.5):(\$1-$ym) with lines notitle, \
+  "<echo -0.9 -$ym 0.2" with boxes notitle
+EOF
+
+rm -f _tmp