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#!/usr/bin/env python3
#
# Copyright 2020 Ettus Research, a National Instruments Brand
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
"""
Utility to run power calibrations with USRPs
"""
import sys
import math
import pickle
import argparse
import uhd
def parse_args():
""" Parse args and return args object """
parser = argparse.ArgumentParser(
description="Run power level calibration for supported USRPs",
)
parser.add_argument(
'--args', default="",
help="USRP Device Args",
)
parser.add_argument(
'-d', '--dir', default='tx',
help="Direction: Must be either rx or tx. From the perspective of the "
"device: rx == receive power levels, tx == transmit power levels.",
choices=['tx', 'rx'])
parser.add_argument(
'--start',
help='Start Frequency. Defaults to lowest available frequency on device. '
'Note that this is only a hint for the device object, which can choose '
'to override this value.', type=float)
parser.add_argument(
'--stop',
help='Stop Frequency. Defaults to highest available frequency on device. '
'Note that this is only a hint for the device object, which can choose '
'to override this value.', type=float)
parser.add_argument(
'--step',
help='Frequency Step. Defaults are device-specific. '
'Note that this is only a hint for the device object, which can choose '
'to override this value. Devices can also measure at non-regular '
'frequencies, e.g., to more accurately cover differences between bands.',
type=float)
parser.add_argument(
'--gain-step', type=float, default=1,
help='Gain Step (dB). Defaults to 1 dB. '
'Note that this is only a hint for the device object, which can choose '
'to override this value. Devices can also measure at non-regular '
'gain intervals.')
parser.add_argument(
'--lo-offset', type=float,
help='LO Offset. This gets applied to every tune request. Note that for '
'TX measurements, there is also an offset applied by --tone-freq. '
'The default value is device-dependent.')
parser.add_argument(
'--amplitude', type=float, default=1./math.sqrt(2),
help='Amplitude of the tone that is generated for tx measurements. '
'Default is 1/sqrt(2), or -3 dBFS.')
parser.add_argument(
'--attenuation', type=float, default=0.0,
help='Amount of attenuation between measurement device and DUT. This will '
'be accounted for by simple addition, it is treated like a measurement error. '
'The argument is generally positive, e.g. 30 means 30 dB of attenuation.')
parser.add_argument(
'--tone-freq', type=float, default=1e6,
help='Frequency of the tone that is generated for Tx measurements. This '
'has the same effect as setting an LO offset, except in software.')
parser.add_argument(
'--antenna', default="*",
help="Select antenna port. A value of '*' means that the calibration "
"will be repeated on all appropriate antenna ports.")
parser.add_argument(
'--channels', default="*",
help="Select channel. A value of '*' means that the calibration "
"will be repeated on all appropriate channels.")
parser.add_argument(
'--meas-dev', default='manual',
help='Type of measurement device that is used')
parser.add_argument(
'-o', '--meas-option', default=[], action='append',
help='Options that are passed to the measurement device')
parser.add_argument(
'--switch', default='manual',
help='Type of switch to be used to connect antennas')
parser.add_argument(
'--switch-option', default=[], action='append',
help='Options that are passed to the switch')
parser.add_argument(
'-r', '--rate', type=float,
help='Sampling rate at which the calibration is performed')
parser.add_argument(
'--store', metavar='filename.pickle',
help='If provided, will store intermediate cal data. This can be analyzed '
'separately, or loaded into the tool with --load.')
parser.add_argument(
'--load', metavar='filename.pickle',
help='If provided, will load intermediate cal data instead of running a '
'measurement.')
return parser.parse_args()
def sanitize_args(usrp, args, default_rate):
"""
Check the args against the USRP object.
"""
assert usrp.get_num_mboards() == 1, \
"Power calibration tools are designed for a single motherboard!"
available_chans = getattr(usrp, 'get_{}_num_channels'.format(args.dir))()
if args.channels == '*':
# * means all channels
channels = list(range(available_chans))
else:
try:
channels = [int(c) for c in args.channels.split(',')]
except ValueError:
raise ValueError("Invalid channel list: {}".format(args.channels))
for chan in channels:
assert chan in range(available_chans), \
"ERROR: Invalid channel: {}. Should be in 0..{}.".format(
chan, available_chans)
print("=== Calibrating for channels:", ", ".join([str(x) for x in channels]))
available_ants = getattr(usrp, 'get_{}_antennas'.format(args.dir))()
if args.antenna == '*':
invalid_antennas = ('CAL', 'LOCAL', 'CAL_LOOPBACK', 'TERMINATION')
antennas = [x for x in available_ants if x not in invalid_antennas]
else:
try:
antennas = args.antenna.split(',')
except ValueError:
raise ValueError("Invalid antenna list: {}".format(args.antenna))
for ant in antennas:
assert ant in available_ants, \
"Invalid antenna: {}. Should be in {}.".format(
ant, available_ants)
print("=== Calibrating for antennas:", ", ".join([str(x) for x in antennas]))
rate = args.rate or default_rate
getattr(usrp, 'set_{}_rate'.format(args.dir))(rate)
actual_rate = getattr(usrp, 'get_{}_rate'.format(args.dir))()
print("=== Requested sampling rate: {} Msps, actual rate: {} Msps"
.format(rate/1e6, actual_rate/1e6))
if args.dir == 'tx' and abs(args.tone_freq) > actual_rate:
raise ValueError(
"The TX tone frequency offset of {} kHz is greater than the sampling rate."
.format(args.tone_freq / 1e3))
return channels, antennas, actual_rate
def init_results(pickle_file):
"""
Initialize results from pickle file, or empty dict
"""
if pickle_file is None:
return {}
with open(pickle_file, 'rb') as results_file:
return pickle.load(results_file)
class CalRunner:
"""
Executor of the calibration routines.
"""
def __init__(self, usrp, usrp_cal, meas_dev, args):
self.usrp = usrp
self.usrp_cal = usrp_cal
self.meas_dev = meas_dev
self.dir = args.dir
self.tone_offset = args.tone_freq if args.dir == 'tx' else 0.0
self.lo_offset = args.lo_offset if args.lo_offset else usrp_cal.lo_offset
if self.lo_offset:
print("=== Using USRP LO offset: {:.2f} MHz"
.format(self.lo_offset / 1e6))
def run(self, chan, freq):
"""
Run all cal steps for a single frequency
"""
print("=== Running calibration at frequency {:.3f} MHz...".format(freq / 1e6))
tune_req = uhd.types.TuneRequest(freq, self.lo_offset)
getattr(self.usrp, 'set_{}_freq'.format(self.dir))(tune_req, chan)
actual_freq = getattr(self.usrp, 'get_{}_freq'.format(self.dir))(chan)
if abs(actual_freq - freq) > 1.0:
print("WARNING: Frequency was coerced from {:.2f} MHz to {:.2f} MHz!"
.format(freq / 1e6, actual_freq / 1e6))
self.meas_dev.set_frequency(actual_freq + self.tone_offset)
getattr(self.usrp_cal, 'run_{}_cal'.format(self.dir))(freq)
def main():
"""Go, go, go!"""
args = parse_args()
print("=== Detecting USRP...")
usrp = uhd.usrp.MultiUSRP(args.args)
print("=== Measurement direction:", args.dir)
print("=== Initializing measurement device...")
meas_dev = uhd.usrp.cal.get_meas_device(args.dir, args.meas_dev, args.meas_option)
meas_dev.power_offset = args.attenuation
# If we're transmitting, then we need to factor in the "attenuation" from us
# not transmitting at full scale
if args.dir == 'tx':
meas_dev.power_offset -= 20 * math.log10(args.amplitude)
print("=== Initializing port connector...")
switch = uhd.usrp.cal.get_switch(args.dir, args.switch, args.switch_option)
print("=== Initializing USRP calibration object...")
usrp_cal = uhd.usrp.cal.get_usrp_calibrator(
usrp, meas_dev, args.dir,
gain_step=args.gain_step,
)
channels, antennas, rate = sanitize_args(usrp, args, usrp_cal.default_rate)
results = init_results(args.load)
usrp_cal.init(
rate=rate,
tone_freq=args.tone_freq,
amplitude=args.amplitude,
)
print("=== Launching calibration...")
cal_runner = CalRunner(usrp, usrp_cal, meas_dev, args)
for chan in channels:
if chan not in results:
results[chan] = {}
for ant in antennas:
if ant in results[chan]:
print("=== Using pickled data for channel {}, antenna {}."
.format(chan, ant))
continue
print("=== Running calibration for channel {}, antenna {}."
.format(chan, ant))
# Set up all the objects
getattr(usrp, 'set_{}_antenna'.format(args.dir))(ant, chan)
switch.connect(chan, ant)
usrp_cal.update_port(chan, ant)
freqs = usrp_cal.init_frequencies(args.start, args.stop, args.step)
usrp_cal.start() # This will activate siggen
# Now calibrate
for freq in freqs:
try:
cal_runner.run(chan, freq)
except RuntimeError as ex:
print("ERROR: Stopping calibration due to exception: {}"
.format(str(ex)))
usrp_cal.stop()
return 1
# Store results for pickling and shut down for next antenna port
results[chan][ant] = usrp_cal.results
usrp_cal.stop() # This will deactivate siggen and store the data
if args.store:
print("=== Storing pickled calibration data to {}...".format(args.store))
with open(args.store, 'wb') as results_file:
pickle.dump(results, results_file)
return 0
if __name__ == "__main__":
try:
sys.exit(main())
except (RuntimeError, ValueError) as ex:
print("ERROR:", str(ex))
sys.exit(1)
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