AR1000

AR1000 Series Resistive Touch Screen Controller DS41393A Contact Information Microchip Technology, Inc. mTouch Touchscreen Controller Products 9055 N. 51st Street, Suite H Brown Deer, WI 53223 www.Microchip.com Phone: 414-355-4675 Fax: 414-355-4775 Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, rfPIC and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor, MXDEV, MXLAB, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code Generation, PICC, PICC-18, PICkit, PICDEM, PICDEM.net, PICtail, PIC32 logo, REAL ICE, rfLAB, Select Mode, Total Endurance, TSHARC, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2009, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified. DS41393A-Page ii © 2009 Microchip Technology, Inc. TABLE OF CONTENTS 1 2 3 4 5 6 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 GENERAL.............................................................................................................................................. 1 FEATURES............................................................................................................................................ 1 APPLICATIONS..................................................................................................................................... 2 ORDERING............................................................................................................................................ 2 BLOCK DIAGRAM ................................................................................................................................. 2 PIN DIAGRAM ....................................................................................................................................... 3 FUNCTIONAL DESCRIPTION .............................................................................................................. 4 MAIN SCHEMATIC ..............................................................................................................................................4 BILL OF MATERIALS ...........................................................................................................................................4 4, 5, 8-WIRE SENSOR SELECTION ......................................................................................................................5 4-WIRE TOUCH SENSOR INTERFACE ....................................................................................................................5 5-WIRE TOUCH SENSOR INTERFACE ....................................................................................................................6 8-WIRE TOUCH SENSOR INTERFACE ....................................................................................................................7 COMMUNICATION INTERFACE ..............................................................................................................................8 7.7.1 7.7.2 7.7.3 7.8 7.9 7.10 7.11 7.12 I2C............................................................................................................................................ 8 SPI........................................................................................................................................... 9 UART..................................................................................................................................... 10 STATUS LED..................................................................................................................................................10 ESD CONSIDERATIONS ...................................................................................................................................11 NOISE CONSIDERATIONS .................................................................................................................................11 TOUCH REPORTING PROTOCOL ........................................................................................................................11 CONFIGURATION REGISTERS ............................................................................................................................12 7.12.1 7.12.2 7.12.3 7.12.4 7.12.5 7.12.6 7.12.7 7.12.8 7.12.9 7.12.10 7.12.11 7.12.12 7.12.13 7.12.14 7.12.15 7.13 7.14 7.15 TouchThreshold Register (offset 0x02)................................................................................. 12 SensitivityFilter Register (offset 0x03)................................................................................... 12 SamplingFast Register (offset 0x04)..................................................................................... 13 SamplingSlow Register (offset 0x05) .................................................................................... 13 AccuracyFilterFast Register (offset 0x06) ............................................................................. 13 AccuracyFilterSlow Register (offset 0x07) ............................................................................ 13 SpeedThreshold Register (offset 0x08) ................................................................................ 13 SleepDelay Register (offset 0x0A) ........................................................................................ 14 PenUpDelay Register (offset 0x0B) ...................................................................................... 14 TouchMode Register (offset 0x0C).................................................................................... 15 TouchOptions Register (offset 0x0D) ................................................................................ 16 CalibrationInset Register (offset 0x0E).............................................................................. 16 PenStateReportDelay Register (offset 0x0F) .................................................................... 17 TouchReportDelay Register (offset 0x11) ......................................................................... 17 User Configuration – Spiking ............................................................................................. 17 COMMAND FORMAT .........................................................................................................................................17 COMMAND RESPONSE .....................................................................................................................................18 COMMANDS ....................................................................................................................................................18 7.15.1 Enable Touch - 0x12 ............................................................................................................. 18 7.15.2 Disable Touch - 0x13 ............................................................................................................ 18 7.15.3 Calibrate - 0x14 ..................................................................................................................... 19 7.15.3.1 How the Calibration Data is Encoded and Stored in EEPROM ..................................... 20 7.15.4 Register Read - 0x20 ............................................................................................................ 21 7.15.5 Register Write - 0x21............................................................................................................. 21 7.15.6 Register Start Address Request - 0x22................................................................................. 21 7.15.7 Registers Write to EEPROM - 0x23 ...................................................................................... 21 7.15.8 EEPROM Read - 0x28 .......................................................................................................... 22 7.15.9 EEPROM Write - 0x29 .......................................................................................................... 22 7.15.10 EEPROM Write to Registers - 0x2B .................................................................................. 22 7.16 CALIBRATION OF TOUCH SENSOR WITH CONTROLLER .........................................................................................23 © 2009 Microchip Technology, Inc. DS41393A-Page iii 8 8.1 8.2 8.3 8.4 8.5 8.6 BASICS OF RESISTIVE SENSORS ................................................................................................... 25 TERMINOLOGY ................................................................................................................................................25 GENERAL .......................................................................................................................................................25 4-WIRE SENSOR .............................................................................................................................................26 8-WIRE SENSOR .............................................................................................................................................27 5-WIRE SENSOR .............................................................................................................................................28 SUMMARY ......................................................................................................................................................28 9 9.1 ELECTRICAL SPECIFICATIONS........................................................................................................ 29 ABSOLUTE MAXIMUM RATINGS(†).....................................................................................................................29 10 10.1 10.2 10.3 PACKAGING .................................................................................................................................... 30 20 LEAD SOIC ...............................................................................................................................................30 20 LEAD SSOP ..............................................................................................................................................31 20 LEAD QFN (ML) ........................................................................................................................................32 FIGURES Figure 1: Block Diagram................................................................................................................................ 2 Figure 2 : Pin Diagrams – SOIC / SSOP and QFN Packages..................................................................... 3 Figure 3 : Main Schematic (SOIC, SSOP package pin out) ........................................................................ 4 Figure 4 : 4-wire Touch Sensor Interface..................................................................................................... 5 Figure 5 : 5-wire Touch Sensor Interface..................................................................................................... 6 Figure 6 : 8-wire Touch Sensor Interface..................................................................................................... 7 Figure 7 : I2C Timing Diagram – Receive Data............................................................................................ 8 Figure 8 : I2C Timing Diagram – Transmit Data........................................................................................... 8 Figure 9 : I2C Timing Diagram – Touch Report Protocol ............................................................................. 9 Figure 10 : I2C Timing Diagram – Command Protocol................................................................................. 9 Figure 11 : SPI Timing Diagram – Bit Timing............................................................................................... 9 Figure 12 : SPI Timing Diagram – Touch Report Protocol ........................................................................10 Figure 13 : SPI Timing Diagram – Command Protocol.............................................................................. 10 Figure 14: 4-Wire Decoding ........................................................................................................................ 26 Figure 15: 8-Wire Decoding ........................................................................................................................ 27 Figure 16: 5-Wire Decoding ........................................................................................................................ 28 Figure 17 : 20 Lead SOIC Package ........................................................................................................... 30 Figure 18 : 20 Lead SSOP Package.......................................................................................................... 31 Figure 19 : 20 Lead QFN Package ............................................................................................................ 32 TABLES Table 1: Ordering Part Numbers................................................................................................................... 2 Table 2: Pin Descriptions .............................................................................................................................. 3 Table 3 : Bill of Materials.............................................................................................................................. 4 Table 4 : 4/8-wire vs 5-wire Selection .......................................................................................................... 5 Table 5 : Communication Selection ............................................................................................................. 8 Table 6 : Communication Pins ..................................................................................................................... 8 Table 7 : Touch Coordinate Reporting Protocol......................................................................................... 11 Table 8 : Configuration Registers .............................................................................................................. 12 Table 9 : Command Set Summary............................................................................................................. 18 Table 10 : Sensor Comparison .................................................................................................................. 25 DS41393A-Page iv © 2009 Microchip Technology, Inc. 1 GENERAL The mTouch AR1000 Series Resistive Touch Screen Controller is a complete, easy to integrate, cost effective, and universal touch screen controller chip solution. The AR1000 Series is designed for high volume, small form factor touch solutions with quick time to market requirements. Developed by touch experts with over 15 years experience, the AR1000 Series has sophisticated proprietary touch screen decoding algorithms allowing it to send your application fully processed and reliable touch coordinates. 2 FEATURES Special Features: • RoHS Compliant • Power-Saving Sleep mode • Industrial Temperature Range • Built in drift compensation algorithm • 128 Bytes of user EEPROM • 4 x 4 mm QFN package Power Requirements: • Operating Voltage: 3.3 to 5.0 volts ±5% • Standby Sleep Current: VDD)........................................................................................................± 20 mA Maximum output current sunk by any I/O pin.................................................................................................... 25 mA Maximum output current sourced by any I/O pin .............................................................................................. 25 mA † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. This device is sensitive to ESD damage and must be handled appropriately. Failure to properly handle and protect the device in an application may cause partial to complete failure of the device. 9.1 © 2009 Microchip Technology, Inc. DS41393A-Page 29 10 PACKAGING 10.1 20 Lead SOIC Figure 17 : 20 Lead SOIC Package DS41393A-Page 30 © 2009 Microchip Technology, Inc. 10.2 20 Lead SSOP Figure 18 : 20 Lead SSOP Package © 2009 Microchip Technology, Inc. DS41393A-Page 31 10.3 20 Lead QFN (ML) The metal plate on the package bottom can be floated, but connecting it to VSS (circuit ground) is recommended. Figure 19 : 20 Lead QFN Package DS41393A-Page 32 © 2009 Microchip Technology, Inc. © 2009 Microchip Technology, Inc. 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