1. Project 1 Part E3 Programming PicoScope ---Looping--

6. # -*- coding: utf-8 -*-
"""
Created on Wed Apr 26 11:37:
@author: Husain
import subprocess
def getMeasurements():
#read oscilloscope
output = subprocess.check_output(['picoscope','/a','Measurements.CSV?'])
#split the lines of the measurements
output = output.split('\n')
#define space
space = " "
#taking the index, and splitting according to comma
channelA = output[1].split(",")
channelB = output[2].split(",")
#taking index, and splitting according to "space"
channelA = channelA[2].split(space)
channelB = channelB[2].split(space)
#check the unit and apply
if channelA[1]=="mV":
channelA=float(channelA[0])*1E-3
elif channelA[1]=="V":
channelA=float(channelA[0])*1
else:
channelA=float(channelA[0])*1E-6
if channelB[1]=="mV":
channelB=float(channelB[0])*1E-3
elif channelB[1]=="V":
channelB=float(channelB[0])*1
channelB=float(channelB[0])*1E-6
return [channelA,channelB]
def signalGenerator(amp,freq):
#define input strings to input to cmd line
amp_string = "picoscope /a Siggen.Amplitude.Value="+str(amp)
freq_string = "picoscope /a Siggen.Frequency.Value="+str(freq)
subprocess.call(amp_string,stdout=False)
subprocess.call(freq_string,stdout=False)
def timeBase(freq):
#find ideal timebase
time_base=1/float(freq)*5/10
#define time_index corellations
time_index = [200E-9,500E-9,1E-6,2E-6,5E-6,10E-6,20E-6,50E-6,100E-6,200E-6,500E-6,1E-3,2E-3,5E-3,10E-3,20E-3,50E-3,100E-3]
#find time index for command line
for n in range(0,len(time_index)):
if time_base<time_index[n]:
break
#write string to command line to change timebase
time_base_string = "picoscope /a CollectionTime.SelectedIndex="+str(n+1)
subprocess.call(time_base_string,stdout=False)
# define the frequency array #
import numpy as np
#Define frequency iteration values
startFrequency = 39000
endFrequency = 41000
intervalFrequency = 10
intervals = (endFrequency-startFrequency)/intervalFrequency + 1
#Define frequency array
frequencySpace = np.linspace(startFrequency,endFrequency,intervals)
#Initialize output measurements
ch1Voltage = np.linspace(startFrequency,endFrequency,intervals)
ch2Voltage = np.linspace(startFrequency,endFrequency,intervals)
impedance = np.linspace(startFrequency,endFrequency,intervals)
# Iterate over frequencySpace and get meeasurements
for n in range(0,len(frequencySpace)):
signalGenerator(2,frequencySpace[n]) # set the function generator
timeBase(frequencySpace[n]) # set the time base
ch1Voltage[n] , ch2Voltage[n] = getMeasurements() # assign measurement
impedance[n] = ch1Voltage[n] / (ch2Voltage[n]/325.0) # define impedance
# Write the data to a CSV file
head = "frequency (Hz), Ch1 Voltage, Ch2 Voltage,Impedance"
np.savetxt("10kHzTO50kHzS100Hz.csv", np.transpose([frequencySpace,ch1Voltage,ch2Voltage,impedance]), delimiter=',', header=head)
# Plot data from python
import matplotlib.pyplot as plt
plt.plot(frequencySpace,impedance)
plt.yscale('log')
plt.show()
#signalGenerator(0.2,80222)
#timeBase(80222)
#print getMeasurements()
#signalGenerator(1.32,50E3)