NI ELVIS INTRODUCTION EXPERIMENT

Introduction

This lab introduces students to NI ELVIS III by showing how students can use the workstation to measure electronic component properties. Then students can build circuits on the protoboard and later analyze them with the NI ELVIS III suite of SFP instruments. This lab shows how to use NI ELVIS III workstation and controlling it with a LabVIEW program. In addition, the students will learn how to use breadboard with parallel and series connection of the components, and build a simple blinking led circuit.

Theory

1. Electrical Connections on Breadboard

On a breadboard there are many tiny holes. Each hole will hold a wire or component lead. The board is divided into four sections; two sets of two rows and two sets of five rows. The five rows in each vertical group are connected together (top to bottom), while each horizontal group at both ends is connected together (side by side) as shown in Figure 1.

Figure. 1. Sections in a breadboard

There are two color Lines that represent the two sets of two rows at opposite ends of the board (as shown in Figure 1). The Blue lines are for the GND (-) connection and the Red lines are for the Voltage (+) connection. Rows A-E represent the first section of five rows, while rows F-G represent the second section (These rows are not connected together horizontally).The numbers on the board represent the columns. Each end of the components that are being connected together must be placed in the same.

When inserting components, bend both ends of the protruding wire on the component and gently push then into the hole.

Figure. 2. Connecting row and columns

One of the ways you can place components on the breadboard is in series. Figure 3 is an example of how to place components in series.

Figure. 3. Connecting components in series

Components can be also connected in parallel. Here in Figure 4, two resistors are connected in parallel.

Figure 4. Connecting components in parallel

2. Basics of LED

Figure 5. Connecting components in parallel

Light emitting diode (LED) is a component that emits light when the applied voltage is greater than some threshold value. LED works when the positive voltage is applied on the + pole (longer lead) and negative voltage is applied on – pole (shorter lead). The physical reasoning behind this working principle can be seen below Figure 6.

Figure 6. Characteristics of an LED

Figure 6 shows LED’s has characteristic voltage-current graph. An LED starts to operate after the voltage is greater than a threshold point. Below that threshold point, LED will not light since the current flow is blocked. After that point, LED would let current flow, therefore the light emitted by the device can be observed. The light intensity is proportional with the forward current magnitude. More current would yield more emitted light.

Hardware

Before programming with the NI ELVIS III, you must first create an NI ELVIS III project. With an NI ELVIS III project, you can group together all the files relevant to your application and run VIs on the NI ELVIS III.

Complete the following steps to create an NI ELVIS III project by using the NI ELVIS III Project template.

0. Click Create New Project in LabVIEW to display the Create Project dialog box.

1. Select Templates » NI ELVIS III from the project category.

2. Select NI ELVIS III Project from the project list.

3. Click Next to configure details of the new project.

4. In Project Name, enter My First ELVIS III Application.

5. In Project Root, enter the path to the directory for saving the project.

6. (Optional) In File Name Prefix, enter a prefix that distinguishes different copies of templates you create.

7. Under Target, select the NI ELVIS III on which to run your application.

8. Click Finish. LabVIEW saves the project and opens the Project Explorer window.

9. Explore the Project Explorer window. For example, expand items in the project tree to find Main.vi. Refer to the Project Documentation folder for detailed information about the NI ELVIS III project.

Project Explorer Window

Use the Project Explorer window to manage the NI ELVIS III project you have created.

You can use the Project Explorer window to complete the following tasks:

• Managing the targets, VIs, and other support files of a project from one location.

• Connecting the host computer to the targets, setting target properties, and deploying VIs to targets.

The following figure shows the Project Explorer window when you add the NI ELVIS III and its chassis to a LabVIEW project. To add a chassis, right-click the NI ELVIS III target in the Project Explorer window and select New » Targets and Devices. Locate the chassis you want to add and click OK.

The Project Explorer window includes the following components:

• Project root—Contains the host computer and the NI ELVIS III you add to the current project. To add more targets to the project, right-click the project root and select New » Targets and Devices from the shortcut menu.

• My Computer—Represents the local or host computer as a target in the project.

  • Build Specifications—Includes build configurations for source distributions and other types of builds available in LabVIEW toolkits and modules.

• RT Target—Represents the NI ELVIS III you add to the project. VIs and libraries that you add to the NI ELVIS III appear under the target in the Project Explorer window.

  • FPGA Target—Represents the FPGA target on the NI ELVIS III.

  • Build Specifications—Includes specifications for building source distributions, stand-alone real-time applications, and zip files.

Safety

Be aware of powering the NI board and be aware of not creating any short circuit on the board (connecting ground and power levels (+5V, 3.3V) is not recommended, and may create some damage on the electronic components, be careful about that.)

Hardware/Software Equipment Check

Prior to starting the lab, make sure the equipment is working by conducting the following steps:

Step 1:   Make sure that the NI setup is open from the ON/OFF switch as it found at the back of the device.

Step 2:   Make sure that you press the open button on the device.

Experiment Details

Procedure:

1. Temperature Unit Conversion with Numerical Tools (30 points)

Figure 1. Block Diagram of Celsius to Fahrenheit Converter

The equation from Celsius to Fahrenheit is 1.8x[°C] + 32 = [°F]

1. By using Numeric segment from Controls in the Front Panel, create the constant values for Celsius degree. You will also see the resulting numeric block in the Block Diagram window.

2. By using Numeric segment from Functions in the Block Diagram, this time create the needed operations.

3. Insert the thermometer on Front Panel, under Numeric segment from Controls.

4. Your final Block Diagram like shown above.

5. Indicate your screenshots providing a simple example on the block diagram.

2. Noise and Filtering (30 points)

1. Create a sinus wave having Amplitude of 1 and Frequency of 20. You may create a Graph from Front Panel under Controls.

2. From the waveform generation function under Signal Processing, create a Uniform White Noise having 0.2 Amplitude and add it to the sine signal.

3. From the Signal Process section on Functions->Waveform Conditioning->Filter, select the rectangular moving average filter. This will give an average value of the samples between a given window size. Provide 20 to the size to half-width of moving average, and share your filtering results.

4. By changing the size of half-width of the rectangular filter to 1,5,20,50 and share your results and comment on which one works as a better filter for a Gaussian noised Sine wave.

5. Now, by using the best filter parameter you had, only change the noise amplitude to 0.5 and 1.

3. Effect of changing duty cycle of the signal on LED behavior (40 points)

Figure 2. Block diagram of the experiment

1. When you click the right click of the mouse for both front and block diagram pages, you will see the indicators and control parameters.

2. You can find the “Simulate signal” from Programming>Waveform>Analog Wfm>Generation>Simulate Signal.

3. Double click on the Simulate Signal, make the signal type is Square, Frequency is 10 Hz, Amplitude is 5, duty cycle is 10 (the starting value).

4. Add “Analog Output” diagram from Academic I/O>Control I/O

5. Double click on the Analog Output, choose Analog Output (n samples) and change the configuration of the pin as B/AO0.

6. You can add Waveform Chart and Waveform Graph from the Silver segment on the Front panel.

7. Insert the screenshot for your results: Duty Cycle is 10,50,100

8. Make the circuit according to below figure:

Report Requirements

The report for Procedure 1 is expected to include:

·       All the screenshots of Block Diagram and Front Panel

The report for Procedure 2 is expected to include

·       All the screenshots of Block Diagram and Front Panel

·       All the screenshots corresponding the graphs obtained by the steps

·       Explanation of how the rectangular filter works

·       Explanation of what is observed by changing the filter

The report for Procedure 3 is expected to include

·       All the screenshots of Block Diagram and Front Panel

·       All the screenshots corresponding the graphs obtained by the steps

·       Comment on the LED behavior, is it like beating (on-off) or continuously lighting? Please, explain the logic behind duty cycle, what is it?