Source code for libmushu.driver.sinusamp
# 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 = [['Sine wave at 50Hz, 16Channels', {'f' : 1, 'fs' : 10, 'channels' : 16}],
['Sine wave at 1kHz, 128Channels', {'f' : 3, 'fs' : 100, 'channels' : 128}]
]
[docs]class SinusAmp(Amplifier):
"""An amplifier that produces sinus data."""
def __init__(self):
self.presets = PRESETS
self.configure(**self.presets[0][1])
self.last_sample = time.time()
@property
[docs] def sample_len(self):
return 1 / self.fs
@property
[docs] def elapsed(self):
return time.time() - self.last_sample
[docs] def get_data(self):
# simulate blocking until we have enough data
elapsed = self.elapsed
if elapsed < self.sample_len:
time.sleep(self.sample_len - elapsed)
dt = self.elapsed
samples = math.floor(self.fs * dt)
t = np.linspace(self.last_sample, self.last_sample + dt, samples)
t = np.array([t for i in range(self.channels)]).T
data = np.sin(np.pi*2*t*self.f)
self.last_sample = time.time()
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 = SinusAmp()
amp.configure(channels=2, fs=10, f=2)
amp.start()
for i in range(20):
t = time.time()
print amp.get_data()
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()