Getting Started with the Audio Adapter+ and Analog Discovery 3

The Audio Adapter+ for Analog Discovery 3 adds the ability to easily test audio equipment to an already fully-featured device. This guide introduces how to quickly get started using it, and takes a quick tour around the relevant features of both the hardware and of WaveForms. You will be presented with the WaveForms UI and be able to see relevant signals being captured from devices capable of audio, such as microphones, speakers, and phones.

Inventory

  • Analog Discovery 3, or other compatible device from its family:
  • Audio Adapter+
  • WaveForms software
  • Computer with a USB port
  • USB cable to connect your computer to the Analog Discovery 3
  • A male-to-male stereo audio cable with 3.5 mm plugs.
  • Optionally, additional audio equipment with 3.5 mm plugs to provide signals of interest or audio output capability - microphones, headphones, speakers, etc

Getting Started and Controls

Setting up the Hardware

This guide uses the following hardware setup, for the purposes of demonstration:

  1. Connect your Analog Discovery 3 to your computer
  2. Connect the Audio Adapter+ to the AD3's 2×15 MTE Connector
  3. Set the Input Mono/Stereo Select Jumper (JP1) on the Audio Adapter+ to the Stereo position
  4. Set the Output Mono/Stereo Select Jumper (JP2) on the Audio Adapter+ to the Stereo position
  5. Use a stereo 3.5 mm audio cable to connect the Input Mono/Stereo connector (J1) to the Output Mono/Stereo connector (J3)

Note that audio input jacks are located on the left side of the device (J1, J2), while audio output jacks are located on the right side of the device (J3, J4), with the adapter facing towards you.

This guide just shows the above loopback configuration, recapturing and visualizing audio signals generated by the AD3. The following are some other things you could do to test out basic audio input and output:

  • Use a stereo 3.5 mm audio cable to connect the Input Mono/Stereo connector (J1) to the audio output of your computer
    • When doing this, use the computer to play some music or a video through the associated audio output, or check for online some test tone files you could use
  • Connect a speaker or headphones to the Output Mono/Stereo connector (J3)
    • Take care if using earbuds or other headphones - experiment with creating sounds without them in your ears first, to make sure you have a feel for the volume a particular amplitude produces.

Using the WaveForms Application

First off, in order to ensure that the amplifier stage of the Audio Adapter+ receives sufficient power to output a signal, open up the Supplies instrument.

In the Supplies instrument, set the positive and negative supplies to provide some voltage in excess of 1.5 V and -1.5 V, respectively. Tracking mode is also useful here. Turn on the Master Enable to begin supplying power to the Audio Adapter+.

Next, we'll generate a signal to re-capture. Open a Wavegen instrument, and set up some waveforms to output through the stereo audio output. In the screenshot to the right, you can see two sine waves being generated, one at 261 Hz (close to middle C), and the other at 440 Hz (the note A4). 5 V amplitude is also used here to showcase the full range of the analog outputs. Click the run button to begin generating tones.

Next, open up the Scope instrument and capture the signal. In the screenshot to the right, you can see the Wavegen digital loopback being used to include the analog output signals in the plot, so that you can see the amplifier in action. Some measurements have been added to clearly show the peak-to-peak Voltages of these signals.

For one final note in this guide, we're going to check out the Audio feature of the scope instrument. Find it in the View dropdown or the menu above the Run button and trigger controls, and enable it. This additional little tab gives you the ability to listen to audio signals captured using the scope, in mono or stereo, using whatever speakers or headphones you happen to have. Playback speed can be controlled and you can speed up or slow down the audio. The audio played is not inherently continuous so you may hear some clipping in the audio as one acquisition ends and the next begins.

For more information on this view and its various configuration settings, check out the in-app Help's Scope → Views → Audio section.

Next Steps

For more documentation for your devices, check out their resource centers: Analog Discovery 3, Audio Adapter+.

For more information on WaveForms visit the WaveForms Resource Center.

For technical support, please visit the Test and Measurement section of the Digilent Forums.