ExpEYES/C2/Communicating-to-ExpEYES-using-Python/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Hello everyone. Welcome to this tutorial on Communicating to ExpEYES using Python. |
| 00:07 | In this tutorial, we will learn:
Introduction to Python Measure AC voltage using Plot window and Python Generate a Sine wave Measure external and internal voltages using Python |
| 00:22 | Measure capacitance and resistance using Plot window & Python
Generate a Square wave Show connections and circuit diagrams for our experiments. |
| 00:34 | Here, I am using:
ExpEYES version 3.1.0 Ubuntu Linux OS version 14.10 |
| 00:43 | To follow this tutorial, you should be familiar with:
ExpEYES Junior interface Basic Python programming. |
| 00:52 | If not, for relevant tutorials, please visit our website. |
| 00:56 | Let's begin with the introduction to Python. |
| 01:00 | Python is simple and easy to learn powerful programming language.
It is Free and Open Source, cross platform high level language. It has effective approach to Object oriented program. |
| 01:15 | Let's make sure that Python is installed on our system. |
| 01:18 | Press CTRL+ ALT and T keys to open the Terminal. |
| 01:22 | To start Python interpreter, type: "python" and press Enter. Details regarding default version of Python will be displayed on the Terminal. |
| 01:36 | The displayed three angle brackets indicate Python prompt(>>>). Now, you are ready to type commands. |
| 01:44 | For more details about Python programming, please visit our website. |
| 01:49 | I will discuss about the channels on the top Panel of the device. |
| 01:54 | On the top Panel, each terminal is assigned to a specific channel number. |
| 02:00 | For example- channel 1 is assigned to A1 and channel 2 to A2. |
| 02:07 | I will show how to connect wires to the device. |
| 02:11 | Device has screw terminals on either side. |
| 02:15 | To make the connection, we insert wires into the terminals and tighten the screws. Here A2 is connected to SINE. |
| 02:22 | This is the circuit diagram. |
| 02:28 | Let's perform an experiment to measure the voltage of A2 and show its Sine wave. |
| 02:36 | Let's see the result on the Plot window. |
| 02:39 | On the Plot window, click on A2 to display the voltage of A2. Voltage of A2 is displayed below. |
| 02:48 | Click on A2 and drag to channel CH1. When we drag A2 to CH1, input data of A2 is assigned to CH1. |
| 02:59 | Move the msec/div slider to show the Sine wave. Click on A2 to show change in voltages of A2. |
| 03:09 | Click on CH1 and drag to FIT. The voltage and frequency of A2 are displayed on the right. |
| 03:16 | We will perform the same experiment and measure voltage of A2 using Python. |
| 03:23 | Please note, to avoid errors on Python interpreter:
Connect the device to the system. Close the Plot window. |
| 03:31 | To import eyes library from ExpEYES, type at the prompt "import expeyes.eyesj". Press Enter. |
| 03:40 | Type: p=expeyes.eyesj.open() and press Enter. open() function returns an object if hardware is found. |
| 03:53 | These lines will load the ExpEYES library and establish connection to the device. |
| 03:58 | To view the voltage of A2, type: "print p.get_voltage" within brackets "2" and press Enter. |
| 04:08 | Output shows voltage of A2. Similarly, we can show the various voltages of A2. |
| 04:15 | Voltage of A2 changes as it is an AC voltage. |
| 04:20 | To generate plots using Python interpreter,
install python-matplotlib library using Synaptic Package Manager. |
| 04:30 | I have already installed python-matplotlib library on my system. |
| 04:36 | To generate plots on Windows Operating system: |
| 04:40 | Download and install,
matplotlib version 1.4.3 numpy version 1.9 or above. |
| 04:49 | Copy the installed ExpEYES files and drivers and paste in C drive. |
| 04:55 | To generate Sine wave- at the python prompt, type: "import expeyes.eyesj" and press Enter. |
| 05:05 | Type: p=expeyes.eyesj.open() and press Enter as before. |
| 05:12 | Type: from pylab import * (asterisk). "from pylab import *" is a program from matplotlib library. Press Enter. |
| 05:26 | Type: ion(). This command sets pylab interactive mode.
Press Enter. |
| 05:35 | Type: "t,v=p.capture" within brackets "2, 200, 100".
"t", "v" are time and voltage vectors. |
| 05:50 | 2 is channel number for A2, 200 is the number of data points, 100 is a time interval between subsequent measurements. |
| 06:02 | Press Enter. |
| 06:04 | To view the output, type: "plot" within brackets "t, v".
plot within brackets t,v generates a Sine wave on a new window. |
| 06:15 | Press Enter. |
| 06:18 | We can generate a Sine wave using the above commands on Windows command prompt as well. |
| 06:26 | Next, let's measure voltage of A1 using a battery as an external voltage source. |
| 06:32 | To measure external voltage source, Ground(GND) is connected to A1 through a battery of 3V. |
| 06:39 | This is the circuit diagram. We will show the value of A1 using Python interpreter. |
| 06:46 | At the python prompt:
Type: "import expeyes.eyesj" and press Enter. |
| 06:53 | Type: p=expeyes.eyesj.open(), and press Enter. |
| 06:59 | Type: print p.get_voltage within brackets 1 and pressEnter. |
| 07:07 | Here, Channel 1 is assigned to A1. Voltage of A1 is displayed on the terminal. |
| 07:14 | Let's measure voltage of A1 using PVS as internal voltage source. |
| 07:20 | In this experiment, PVS is connected to A1. |
| 07:24 | This is the circuit diagram. |
| 07:28 | Back to the terminal. Type: print p.set_voltage within brackets 3 and press Enter. |
| 07:39 | Here, voltage of PVS will be set to 3 volts. Voltage of PVS is displayed. |
| 07:47 | Type: "print p.get_voltage" within brackets "1" and press Enter. voltage of A1 is displayed on the terminal. |
| 07:59 | Now, I will demonstrate AC and DC components of a voltage using capacitor and resistor. And also, generate a square wave. |
| 08:11 | In this experiment,
A1 is connected to SQR1. SQR1 is connected to A2 through a capacitor. A2 is connected to ground(GND) through 200K resistor. |
| 08:25 | This is the circuit diagram. |
| 08:27 | Let's see the result on the Plot window. |
| 08:31 | On the Plot window, click on Measure C on IN1 button. |
| 08:36 | Capacitance of IN1 is displayed as -0.6 pF (pico farads). |
| 08:42 | Click on Measure R on SEN button. Resistance of SEN is displayed as 560 Ω(ohms). |
| 08:51 | Please note you may get slightly different values of Capacitance & Resistance. |
| 08:57 | Click on SQ1 and drag to CH1.
SQ1 is assigned to channel CH1. |
| 09:04 | Click on A2 and drag to CH2.
A2 is assigned to channel CH2. |
| 09:12 | Click on SQR1 check box to show the Square waves. Move the msec/div slider to adjust the waves. |
| 09:23 | Click on CH2 and drag to FIT. Voltage and frequency of A2 are displayed on the right side. |
| 09:32 | We will perform the same experiment to measure Capacitance, Resistance and generate a Square wave using Python interpreter. |
| 09:41 | At the python prompt, type: "import expeyes.eyesj" and press Enter. |
| 09:50 | Type: p=expeyes.eyesj.open() and press Enter. |
| 09:58 | To display the Capacitance value, type: p.measure_cap() and press Enter. |
| 10:07 | Capacitance value is displayed on the terminal. |
| 10:11 | To display the Resistance value, type: p.measure_res() and press Enter.
Resistance value is displayed on the terminal. |
| 10:24 | To generate a Square wave, type: from pylab import *(asterisk) and press Enter.
Type: ion() and press Enter. |
| 10:36 | Type: print p.set_sqr1 within brackets 100 and press Enter. Here 100 is the frequency of the square wave. |
| 10:49 | Type: t,v=p.capture within brackets 6, 400, 100 and press Enter. |
| 11:00 | Type: plot within brackets t,v. plot within brackets t,v generates a square wave on a new window. |
| 11:12 | Press Enter. |
| 11:14 | Let's summarize. |
| 11:17 | In this tutorial, we have learnt:
Introduction to Python Measure AC voltage using Plot window & Python Generate a Sine wave Measure external and internal voltages using Python |
| 11:33 | Measure capacitance & resistance using Plot window & Python
Generate a Square wave Show connections & circuit diagrams for our experiments. |
| 11:45 | As an assignment,Measure the resistance of your finger using Plot window.
Using python, generate a combination of Sine and Square waves. |
| 11:56 | Show circuit diagrams for the above experiments. |
| 11:59 | This video summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it. |
| 12:07 | We conduct workshops using Spoken Tutorials and give certificates. Please contact us. |
| 12:13 | The Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. |
| 12:20 | This tutorial is contributed by Kaushik Datta and Madhuri Ganapathi.Thank you for joining. |
