myFilter: Covering the Basics of Passive Filters

[BenClark]

Overview:

Use an NI-myDAQ and LabVIEW to learn the basics of making Butterworth filters.

Description:

The code contains three parts to make a tutorial designed for Electronic Engineering students in their first or second year of university:

1. A lesson on the basic concepts behind designing a high-pass frequency filter:
2. A calculator which designs a circuit to create your own filters.
3. A test which makes use of many myDAQ features to analyze the response of designed filters.

For this tutorial, you will need:

• An NI-myDAQ with myProtoboard.
• Resistors, Capacitors, Inductors and Wire.
• A speaker with 3.5mm jack connector.

Steps on How to Use the Code:

For instructions on how to set up a sample system, please read the attached manual.

1. Extract the appropriate zip file below and open myFilter.lvproj in LabVIEW
2. Open "main.vi" from within the project.
3. To make use of the DAQ analysis part of the tutorial, please update the myDAQ reference control.
4. Run the code
5. Follow the tutorial inside the first tab by clicking on the basics or design theory tabs.
6. Click the calculator tab and input your target system to receive a list of components to use in the filter.
7. Click the “myDAQ Acquisition” tab to see the signal analysis section.
8. Click the “Run Test” button whilst the switch is in the “Frequency Sweep” position to play a sequence of sounds, the myDAQ will send the signals through the filter and then play the sound back through the AUDIO OUT port.
9. When in the “Sound Input from Speakers” position, the myDAQ will record 5 seconds of sound coming into the AUDIO IN port, and then play back the filtered sound through the AUDIO OUT port.
10. In the continuous input section the myDAQ will process any incoming signal to the filter (which should also be connected to AI1) and display the output of the filter (connected to AI0)

Other Requirements:

• LabVIEW 2009 or later with latest DAQmx drivers.
  

Block Diagram Screenshot: