Author: Praveen Patil

Prerequisite reading: https://blog.fossasia.org/communicating-with-pocket-science-lab-via-usb-and-capturing-and-plotting-sine-waves/ Interfacing with the hardware of PSLab, fetching the data and plotting it is very simple and straight forward. Various sensors can be connected to PSLab and data can be fetched with a simple python code as shown in the following example... >>> from PSL import sciencelab >>> I = sciencelab.connect() # Initializing: Returns None if device isn't found. The initialization process connects to tty device and loads calibration values. # An example function that measures voltage present at the specified analog input >>> print I.get_average_voltage('CH1') # An example to capture and plot data >>> I.set_gain('CH1', 3) # set input CH1 to +/-4V range >>> I.set_sine1(1000) # generate 1kHz sine wave on output W1 >>> x,y = I.capture1('CH1', 1000, 10) # digitize CH1 1000 times, with 10 usec interval >>> plot(x,y) >>> show() # An example function to get data from magnetometer sensor connected to PSLab >>> from PSL.SENSORS import HMC5883L #A 3-axis magnetometer >>> M = HMC5883L.connect() >>> Gx,Gy,Gz = M.getRaw() The module sciencelab.py contains all the functions required for communicating with PSLab hardware. It also contains some utility functions. The class ScienceLab() contains methods that can be used to interact with the PSLab. After initiating this class, all the features built into the device can be accessed  using various function calls. Capture1 : for capturing one trace capture1(ch, ns, tg) Arguments ch  : Channel to select as input. ['CH1'..'CH3','SEN'] ns  :  Number of samples to fetch. Maximum 10000 tg   :  Time gap between samples in microseconds #Example >>> x,y = I.capture1('CH1', 1000, 10) # digitize CH1 1000 times, with 10 usec interval Returns : Arrays X(timestamps),Y(Corresponding Voltage values) Capture2 : for capturing two traces capture2(ns, tg, TraceOneRemap='CH1') Arguments ns :  Number of samples to fetch. Maximum 5000 tg  :  Time gap between samples in microseconds TraceOneRemap :   Choose the analogue input for channel 1 (Like MIC OR SEN). It is connected to CH1 by default. Channel 2 always reads CH2. #Example >>> x,y1,y2 = I.capture2(1600,1.75,'CH1') # digitize CH1 and CH2, 1600 times, with 1.75 usec interval Returns: Arrays X(timestamps),Y1(Voltage at CH1),Y2(Voltage at CH2) Capture4 : for capturing four taces capture4(ns, tg, TraceOneRemap='CH1') Arguments ns:   Number of samples to fetch. Maximum 2500 tg :   Time gap between samples in microseconds. Minimum 1.75uS TraceOneRemap :   Choose the analogue input for channel 1 (Like MIC OR SEN). It is connected to CH1 by default. Channel 2 always reads CH2, channel 3 always reads CH3 and MIC is channel 4 (CH4) #Example >>> x,y1,y2,y3,y4 = I.capture4(800,1.75) # digitize CH1-CH4, 800 times, with 1.75 usec interval Returns: Arrays X(timestamps),Y1(Voltage at CH1),Y2(Voltage at CH2),Y3(Voltage at CH3),Y4(Voltage at CH4) Capture_multiple : for capturing multiple traces capture_multiple(samples, tg, *args) Arguments samples:   Number of samples to fetch. Maximum 10000/(total specified channels) tg :   Time gap between samples in microseconds. *args :   channel names # Example >>> from pylab import * >>> I=interface.Interface() >>> x,y1,y2,y3,y4 = I.capture_multiple(800,1.75,'CH1','CH2','MIC','SEN') >>> plot(x,y1) >>> plot(x,y2) >>> plot(x,y3) >>> plot(x,y4) >>> show() Returns: Arrays X(timestamps),Y1,Y2 ... Capture_fullspeed :…