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 configure(self, f, fs, channels): self.f = f self.fs = fs self.channels = channels
[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()