ATSAMD20-QTRDEMO Microchip

USER GUIDE AT08578: SAM D20 QTouch Robustness Demo Atmel QTouch Description The Atmel SMART SAM D20 QTouch Robustness Demo demonstrates the high performance capacitive touch support of the Peripheral Touch Controller (PTC) while achieving best-in-class conducted immunity and moisture tolerance. The demo implements a robustness solution that allows customers to easily incorporate the Atmel QTouch technology into designs that require high levels of noise immunity and moisture tolerance. Features Six self-capacitance buttons with Philipp Spring Four mutual-capacitance buttons Individual LEDs for indicating button status One 8-channel mutual-capacitance slider Seven LEDs to indicate slider position Buzzer for audio feedback On-board Embedded Debugger module Connectivity with QTouch Analyzer On-board Embedded Debugger module for programming/debugging and QDebug data streaming Atmel-42324A-SAM-D20-QTouch-Robustness-Demo UserGuide 102014 Table of Contents 1 Overview ..................................................................................................................... 3 2 Hardware Description ................................................................................................. 4 2.1 Block Diagram ....................................................................................................................................... 4 3 Pin Configuration ........................................................................................................ 5 3.1 Mutual Capacitance Sensors ................................................................................................................ 5 3.2 Self Capacitance Sensors ..................................................................................................................... 5 3.3 Indication ............................................................................................................................................... 6 3.4 Communication Interface ...................................................................................................................... 6 4 Unit Assembly ............................................................................................................. 7 5 Powering up the Kit ..................................................................................................... 8 5.1 USB Port ............................................................................................................................................... 8 5.2 External DC Power Supply .................................................................................................................... 8 6 Embedded Debugger (EDBG) ..................................................................................... 9 7 Connecting to QTouch Analyzer .............................................................................. 10 8 Switch Operation ....................................................................................................... 12 8.2 Noise Handling .................................................................................................................................... 12 8.3 Moisture Tolerance.............................................................................................................................. 12 9 Board Operation ........................................................................................................ 13 9.1 Product Layout .................................................................................................................................... 13 9.2 Button Description ............................................................................................................................... 13 9.2.1 Power Button .......................................................................................................................... 13 9.2.2 Lock Button ............................................................................................................................. 13 9.3 Operating Modes of the Kit .................................................................................................................. 14 9.3.1 Application Flow ..................................................................................................................... 14 9.3.2 Normal Mode .......................................................................................................................... 14 9.3.3 Mode Change ......................................................................................................................... 14 9.3.4 Settings Mode ......................................................................................................................... 15 9.3.4.1 LED Brightness Adjustment .................................................................................... 15 9.3.4.2 Buzzer Volume Adjustment .................................................................................... 15 10 Schematic .................................................................................................................. 17 10.1 MCU and Sensor Configuration Section.............................................................................................. 17 10.2 LED, Buzzer, and Switch Section ........................................................................................................ 18 10.3 Power Supply Section ......................................................................................................................... 19 10.4 Sensor Board ...................................................................................................................................... 19 11 PCB Design ................................................................................................................ 20 11.1 Main MCU PCB Top Layer ............................................................................................................... 20 11.2 Main MCU PCB Bottom Layer .......................................................................................................... 21 11.3 Sensor PCB Top Layer .................................................................................................................... 22 11.4 Sensor PCB Bottom Layer ............................................................................................................... 23 12 Bill of Materials .......................................................................................................... 24 13 References ................................................................................................................. 25 14 Revision History ........................................................................................................ 26 SAM D20 QTouch Robustness Demo USER GUIDE 2 2 Atmel-42324A-SAM-D20-QTouch-Robustness-Demo UserGuide 102014