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#!/usr/bin/env python3
import matplotlib.pyplot as plt
import numpy as np
import os
import subprocess
import sys
if __name__ == '__main__':
try:
duration = int(sys.argv[1])
except IndexError:
print('Usage: msp430-etv <duration>')
except ValueError:
print('Error: duration "{}" is not a number'.format(sys.argv[1]))
if not 'LD_LIBRARY_PATH' in os.environ:
os.environ['LD_LIBRARY_PATH'] = '{}/var/projects/msp430/MSP430Flasher_1.3.7'.format(os.environ['HOME'])
energytrace_cmd = '{}/var/source/energytrace-util/energytrace'.format(os.environ['HOME'])
res = subprocess.run([energytrace_cmd, str(duration)], stdout = subprocess.PIPE, universal_newlines = True)
lines = res.stdout.split('\n')
data_count = sum(map(lambda x: len(x) > 0 and x[0] != '#', lines))
data_lines = filter(lambda x: len(x) > 0 and x[0] != '#', lines)
data = np.empty((data_count, 4))
for i, line in enumerate(data_lines):
timestamp, current, voltage, total_energy = map(float, line.split(' '))
data[i] = [timestamp, current, voltage, total_energy]
m_duration = data[-1, 0] - data[0, 0]
m_energy = data[-1, 3] - data[0, 3]
m_calc_energy = np.sum(data[1:, 1] * data[1:, 2] * (data[1:, 0] - data[:-1, 0]))
print('{:d} measurements in {:.2f} s = {:.0f} Hz sample rate'.format(
data_count, m_duration, data_count / m_duration))
print('Reported energy: E = {:f} J'.format(m_energy))
print('Calculated energy: U*I*t = {:f} J'.format(m_calc_energy))
pwrhandle, = plt.plot(data[:, 0], data[:, 1] * data[:, 2], 'b-', label='U*I', markersize=1)
#energyhandle, = plt.plot(data[1:, 0], (data[1:, 3] - data[:-1, 3]) / (data[1:, 0] - data[:-1, 0]), 'r-', label='E/Δt', markersize=1)
plt.legend(handles=[pwrhandle])
plt.xlabel('Time [s]')
plt.ylabel('Power [W]')
plt.grid(True)
plt.show()
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