scripts: New script to measure many samples of RTT (calibration)

In order to obtain good calibration parameters is worthy to take
many samples of the variable values as the RTT.
This script search the WR monitor output for a key and computes
the average value (and standard deviation) of it.

meas_tools/calib_params.py

@@ -0,0 +1,105 @@
+#!   /usr/bin/env   python
+#    coding: utf8
+'''
+A simple script to take some WR link variables and perform statistics.
+Useful for calibration procedure.
+
+@file
+@author Felipe Torres González (torresfelipex1<AT>gmail.com)
+@date Created on June, 2017
+@copyright GPL v3
+'''
+
+# Calibration tool
+# Copyright (C) 2017  Felipe Torres González (torresfelipex1<AT>gmail.com)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# System modules
+import re
+import math
+import time
+import subprocess
+import argparse as arg
+
+# Define the shell command to retrieve the WR link status
+MONITOR = "gpa_ctrl ppsi"
+
+# Regular expressions
+RTT_REGEX = r'servo/rtt.*\d+'
+RRTT = re.compile(RTT_REGEX)
+DRXM_REGEX = r'servo/drxm.*\d+'
+RRXM = re.compile(DRXM_REGEX)
+DRXS_REGEX = r'servo/drxs.*\d+'
+RRXS = re.compile(DRXS_REGEX)
+
+def main():
+    """Simple script to compute the average and stdev of RTT or CRTT"""
+    parser = arg.ArgumentParser(description="Simple script to compute the \
+                                average and stdev of RTT or CRTT")
+    parser.add_argument('--key', '-k', help='Key to filter and compute its statistics.',
+                        dest="key", default="rtt")
+    parser.add_argument('--samples', '-s', help="How many samples take to compute the average",
+                        dest="samples", default=100, type=int)
+    parser.add_argument('--interval', '-i', help="Time between samples", dest="inter",
+                        default=0, type=int)
+
+    args = parser.parse_args()
+
+    print("Taking %d samples of %s (each %d s)..." %
+          (args.samples, args.key, args.inter))
+
+    values = [None, ] * args.samples
+
+    if args.key == "rtt":
+        regex = RRTT
+    else:
+        print("Invalid key used as argument (%s)" % args.key)
+        exit(1)
+
+    # Take bitslides to obtain the CRTT
+    statout = subprocess.check_output([MONITOR], shell=True,
+                                      stderr=subprocess.STDOUT,
+                                      universal_newlines=True)
+    drxm = int(RRXM.search(statout).group().split(":")[-1].strip())
+    drxs = int(RRXS.search(statout).group().split(":")[-1].strip())
+    print("BitSlides: M -> %d ps | S -> %d ps" % (drxm, drxs))
+    sub = drxm + drxs
+
+    for i in range(args.samples):
+        statout = subprocess.check_output([MONITOR], shell=True,
+                                          stderr=subprocess.STDOUT,
+                                          universal_newlines=True)
+
+        values[i] = int(regex.search(statout).group().split(":")[-1].strip()) - sub
+        time.sleep(args.inter)
+
+    # Average
+    avg = 0
+    for i in range(args.samples):
+        avg += values[i]
+    avg /= args.samples
+
+    # Standard Deviation
+    std = 0
+    for i in range(args.samples):
+        std += (values[i]-avg)**2
+
+    std = math.sqrt(std/args.samples)
+
+    print("Average: %d ps | StDev: %d ps" % (avg, std))
+
+if __name__ == '__main__':
+    main()
+