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Analyze Touch Data Using QTouch® Analyzer

Last modified by Microchip on 2023/11/09 09:02
Contents

Objective

QTouch® Analyzer, which is part of QTouch Composer, provides near real-time visualization of QTouch measurement data. QTouch Analyzer can be used throughout the different phases of a development cycle. Using the basic touch sensor debugging information provided by QTouch Analyzer, it is possible to analyze sensor signal and touch delta. This debugging information can be used to appropriately tune sensor parameters such as Gain, Filter Level, Detect Threshold, and global parameters such as Drift Rates.

Basic Touch Sensor Debugging Information

The basic touch sensor debugging information is categorized into Signal, Reference, and Delta.

  • Signal: Raw measurement value of a channel. This value increases with touch as shown.

Signal: Raw measurement value of a channel

  • Reference: Long term average measurement on a channel.
    • Initial value obtained from calibration process

Reference: Long term average measurement on a channel

  • (Touch) Delta: Signal - Reference
    • Difference between Signal and Reference
    • Delta increases with touch

(Touch) Delta: Signal - Reference

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Reference Materials

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Procedure

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This tutorial builds on the material found on the "Introduction to PTC on AVR" page. Make sure you've completed that before continuing with this project.

QTouch Start Page

Go to the QTouch Start page by clicking on the following icon:

QTouch Start Icon

Connected Kits

The ATmega328PB Xplained Kit connected through QDebug can be seen in the Connected Kits pane.

Connected Kits pane

Analyze Touch Data

Right-click on the connected kit and select Analyze Touch Data.

Analyze Touch Data menu option

The QTouch Analyzer window can also be opened by clicking on the QTouch Analyzer icon:

QTouch Analyzer icon

Connect

In the QTouch Analyzer window, click Connect.

QTouch Analyzer window

If the project ID of this QTouch project matches an existing project, a pop-up window appears, requesting confirmation to load the layout. Click Yes.

Pop-up AtmelStudio window requesting confirmation to load the layout

Verify Connection

To verify that your board is now connected, you can check the bottom left corner of the QTouch Analyzer window.

QTouch Analyzer window

Signal Selection

Click on Signal Selection and select Signal, Delta, and Reference for Button0.

QTopuch Anayzer View window

Start Reading

Click on Start Reading.

Start Reading button in QTouch Analyzer

Touch Signal

Touch the sensor and observe the change in Signal and Delta.

Signal and Delta graphs

By default, QTouch Analyzer displays the Graph View. It also provides a Tabular View for numerical visualization of touch data. You can access it by clicking on Tabular View.

Tabular View for numerical visualization

After completing this lab, click on Stop Reading. This will prevent QTouch Analyzer from collecting touch data over a long period of time, which might slow down your computer.

Stop Reading button in QTouch Analyzer

Results

The kit is connected to QTouch Analyzer and displays sensor signal, delta, and reference values.

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