Back to modules

Beginner Analog Discovery, Module 1

Voltage Instrument

DC Power Supplies

Applying voltage using the Analog Discovery's Voltage instrument to a diode to produce light.
26.4K
Start
×
Voltmeter Instrument

Measuring DC Voltages

Utilize the Analog Discovery's Voltmeter instrument to measure voltage in a circuit.
15.9K
Start
×
Basic Periodic Signals

Project 1: Waveform Generator

Using the Analog Discovery's arbitrary waveform generator to apply a time-varying signal to an LED to make it flash on and off. This project builds off of the previous Analog Discovery material.
14.9K
Start
×
Sinusoids and Swept Signals

Project 2: Waveform Generator

Use the arbitrary waveform generator on the Analog Discovery to apply sinusoidal and swept sinusoidal voltages to a speaker.
15.6K
Start
×
Modulated Signals

Project 3: Waveform Generator

Use the arbitrary waveform generator on the Analog Discovery to create frequency modulated signals and apply them to a speaker. This project builds off of the previous Analog Discovery material.
10.5K
Start
×
Audio and .wav Files

Project 4: Waveform Generator

Use the Analog Discovery to play back .wav files through the speaker included in the analog parts kit. This project builds off of material presented in previous Analog Discovery projects.
14.5K
Start
×
Importing Files and Playing “Scales”

Project 5: Waveform Generator

Use the Analog Discovery's ability to import "custom" waveforms from a file.
11.2K
Start
×
Creating Signals from Math and “Beating”

Project 6: Waveform Generator

Use the Analog Discovery's ability to create "custom" waveforms according to a mathematical function.
9.40K
Start
×
Basic Waveform Measurement and Display

Project 1: Oscilloscope

Introduces the Analog Discovery's Oscilloscope instrument. Explains the basics of the ways in which voltages are acquired and displayed by the oscilloscope.
21.0K
Start
×
Triggered Acquisition

Project 2: Oscilloscope

The Arbitrary waveform generator instrument will be used to apply relatively rapidly varying wave forms to the oscilloscope, and then triggering of the waveform will be used to make the waveform easier to view and analyze.
11.9K
Start
×
Measurements and Cursors

Project 3: Oscilloscope

How to use some of the most basic and common oscilloscope tools to simplify the measurement process.
13.4K
Start
×
Math Channels

Project 4: Oscilloscope

Introduces the use of the math channel function on the Analog Discovery. This function allows the user to perform a wide variety of mathematical operations, all of which can be applied to the voltages being measured.
14.2K
Start
×
XY Plots

Project 5: Oscilloscope

Use the Analog Discovery to plot the voltage-current characteristics of a light emitting diode.
16.6K
Start
×
Exporting data

Project 6: Oscilloscope

Export the voltage-current data of a light emitting diode.
13.0K
Start
×
Single Sequence Acquisition

Project 7: Oscilloscope

Acquiring vibration data from the piezoelectric sensor from the analog parts kit.
9.10K
Start
×

Modulated Signals

Project 3: Waveform Generator

Modulated Signals

Project 3: Waveform Generator

Introduction

Related Material:
Modulation

In this experiment, we will use the Arbitrary Waveform Generator (AWG) on the Analog Discovery™ to create frequency modulated signals and apply them to a speaker. Modulated signals have one or more of their parameters (frequency or amplitude) vary according to some other signal.

Modulated sinusoids are composed of a carrier signal which is modified in some way by a second signal, called the baseband signal. The baseband signal is the original frequency range of a signal before being converted or modulated. We will be examining amplitude modulation and frequency modulation. In amplitude modulation, the amplitude of the carrier signal is changed based on the baseband signal. In frequency modulation, the frequency of the carrier signal is changed based on the baseband signal.

Our goal in this project is to obtain an intuitive feeling for the process of modulation. This experiment reiterates the use of the Sweep tab on the Analog Discovery's arbitrary waveform generator instrument.

Before you begin, you should:
  • Be able to use the Analog Discovery waveform generator to apply Sinusoids and Swept Signals to a circuit.
  • Sketch a sinusoidal signal. Label the amplitude and period on the sketch.
  • Determine the frequency of a sinusoidal signal from its period.
  • State how the period of a swept signal changes with time.
After you're done, you should:
  • Use the Analog Discovery waveform generator to create frequency and amplitude modulated signals.

Inventory:

Qty Description Typical Image Schematic Symbol Breadboard Image
1 Buzzer/Speaker
The Buzzer/Speaker in the analog parts kit has two terminals. If a time-varying voltage is applied between the terminals a film in the speaker vibrates, converting the voltage waveform to a pressure waveform with a similar “shape”. Note: The speaker in your parts kit may have different markings than the one pictured.

Procedures

Shortcut!

If you have completed the Sinusoids and Swept Signals project and your circuit is still intact, feel free to skip to Step 2 of this exercise.

Step 1: Understanding the Circuit

A. Circuit Schematic

  1. Connect one terminal of the speaker to the W1 terminal of your Analog Discovery.

  2. Connect the other terminal of the speaker to a ground terminal on your Analog Discovery.

B. Create Circuit

  1. Insert the terminals of the speaker into your breadboard so that they are in different rows.

  2. Connect W1 (the yellow wire) to one terminal of the speaker.

  3. Connect ground (, the black wire) to the other speaker terminal.

Step 2: Set up Instruments

A. Open WaveGen Instrument

  1. Open WaveForms™ to view the main window.

  2. Click on the WaveGen icon to open the waveform generator.

Step 3: Experiment

A. Apply a Frequency Modulated Voltage to the Speaker

The images above are screenshots of Digilent WaveForms running on Microsoft Windows 7.
  1. Click on Run AWG1 or Run All. An irritating noise, not unlike a police siren, should emit from your speaker.

Test Your Knowledge!

  1. Try changing the carrier wave frequency and the baseband (FM) frequency. Try to interpret the effect of these parameters on the sound you hear.

    • Note: Use ranges for the carrier frequencies that are over the human auditory range (about 50Hz to 20kHz). Use baseband frequencies which are considerably smaller that the carrier frequencies (about 100mHz to 20Hz).

  2. Try frequency modulating the signal with a square wave. (Just change the “FM” signal type to “Square”. You should hear a signal with two distinct tones—an alternating high and a low frequency.

  3. Try amplitude modulating a signal. To do this:
    • Choose a carrier wave frequency of 1kHz.
    • De-select (un-check) the FM box.
    • Select (check) the AM box.
    • Choose a “Sine” AM signal. Set the frequency of the AM signal to 500mHz, and its Amplitude/Index to 80%. The default choices on the other parameters should be fine.

    • Click on Run AWG1 or Run All. You should hear a tone from your speaker. The volume of the tone should increase and decrease with time, consistent with the fact that you are varying the amplitude of the signal with time.

  4. Try frequency modulating the signal with a square wave and a triangle wave. Do these have the effect you expect?
  • Other product and company names mentioned herein are trademarks or trade names of their respective companies. © 2014 Digilent Inc. All rights reserved.
  • Circuit and breadboard images were created using Fritzing.
Previous
Next