Source code for libmushu.driver.randomamp
# randomamp.py
# Copyright (C) 2013 Bastian Venthur
#
# 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 2
# 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import division
import time
import math
import json
import numpy as np
from libmushu.amplifier import Amplifier
PRESETS = [
['Random noise at 50Hz, 16Channels',
{'fs' : 50, 'channels' : 16}],
['Random noise at 1kHz, 128Channels',
{'fs' : 1000, 'channels' : 128}]
]
[docs]class RandomAmp(Amplifier):
"""An amplifier that produces random data."""
def __init__(self):
self.presets = PRESETS
self.channels = 17
self.fs = 100
[docs] def start(self):
self.last_sample = time.time()
@property
[docs] def sample_len(self):
return 1 / self.fs
[docs] def get_data(self):
# simulate blocking until we have enough data
elapsed = time.time() - self.last_sample
if elapsed < self.sample_len:
time.sleep(self.sample_len - elapsed)
# ready
dt = time.time() - self.last_sample
samples = math.floor(self.fs * dt)
# actual time according to number of samples we're sending out
dt = samples / self.fs
data = np.random.randint(0, 1024, (samples, self.channels))
self.last_sample += dt
return data, []
[docs] def get_channels(self):
return ['Ch_%d' % i for i in range(self.channels)]
[docs] def get_sampling_frequency(self):
return self.fs
@staticmethod
[docs] def is_available():
return True
if __name__ == '__main__':
pass
# amp = RandomAmp()
# amp.start()
# for i in range(10):
# t = time.time()
# print amp.get_data()
# print
# print "FS:", 1 / (time.time() - t)
# print
# amp.stop()
#
# # the same using a context manager, start and stop are called by the
# # context manager
# with amp as a:
# for i in range(10):
# print a.get_data()