mTouch电容触摸屏解决方案

1、Capacitive touch technologies 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide1mTouch Capacitive Touch Solutions 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide2What is mTouch Capacitive Touch Sensing?Alternative to traditional push- buttonReq

2、uires no mechanical movementEnables a completely sealed and modern-looking designLower costUsed in any application with a User InterfaceAppliance Consumer Industrial Medical AutomotiveCould be Keys or Slider 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide3Introduction of

3、 fingerproduces a parallel capacitanceCsCPEquivalent CircuitSo we need to measure a capacitance and detect a shift in its valueHow does Cap Touch work?CPFSensor Capacitance (CS) = CP + CFIron in Blood CF 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide4Capacitive mTouch S

4、olutionsSensingComparatorComparator with SR LatchIntegrated Capacitive Sensing ModuleNEWCharge Time Measurement Unit Module 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide5MCU PERFORMANCEAVAILABLE CHANNELSNEW14Up to 16Methods for Capacitive Touch Sensing 2008 Microchip T

5、echnology Incorporated. All Rights Reserved.Class TitleSlide6mTouch is using two methodsRelaxation oscillatorMeasures Frequency based on a capacitance valueNeeds Comparator, SR Latch module or new Capacitive Sensing ModuleCharge Voltage Direct MeasurementCharges a capacitance with a fixed current fo

6、r a fixed time. Then measure the voltage with the A/DUsed by CTMU (Charge Time Measurement Unit)New App Note using PIC10F 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide7Can be used as:One Key: On/Off buttonProximity sensor: Detecting the hand coming close to the keypadL

7、ower standby power consumption Marketing Wow factorCan drive LED or Buzzer Using PIC10F204/6SW provided AN1202It is the only 6pins Micro-based solutionMicrocontrollers with S/R Latch moduleComparator with mux and S/R latchPIC16F610/616, PIC16HV610/616PIC16F690 family PIC16F88X family PIC18F14K50Firm

8、ware:Approximately 250 Instructions30 - 40 Bytes RAMNEW 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide8New Capacitive Sensing Module for PIC16F 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide9Use the Relaxation Oscillator Method Compare to t

9、he SR Latch Module:More Hardware IntegrationNo external component required Save 3 I/OsMore Inputs8 Channels on 28 pins = up to 16 Keys (4x4 Matrix) 16 Channels on 44 pins = up to 64 Keys (8x8 Matrix)Can operate in Sleep Mode to save powerWDT as Time BaseThe first family is the PIC16F72XCharge Time m

10、easurement Unit CTMU 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide10Consists of current source and control logicWorks in conjunction with the A/DCan be used toMeasure time, capacitance or change in capacitanceFixed current source charge the Capacitance for a fixed time

11、Allows for faster button response time compare to the Relaxation OscillatorProvides up to 16 channels64 Keys MatrixThe first family is the PIC24FGA1/GB1When to use what? 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide11Thanks to our large offer, the choice will be mainly

12、 dictated by the application needs:I/Os, Memory Communication DisplayCPU performance required USB, Ethernet.For example:So what is the cost per key?We cant answer because it depends on:Customer volumeApplication needs: Low end with a lot of keys / High End with only a couple of keysSo work with the

13、customer to fully understand the application firstOne Key or Proximity sensorGo Cheap and Easy with PIC10FSmall 4 keys keyboardThe S/R latch module is the most cost effective solution on the market today15 keys with CommunicationPIC16F72X is the way to goUI with Display, USB, SpeechHello PIC24FGB1Wh

14、at Are Some Of The Capacitive Touch Technology Challenges? 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide12Detecting a 5%-20% shift in pico-FaradsHeat, Humidity, adjacent metal, and environmental shiftPeople sometimes wear gloves, touch with nails, etc.So independently

15、of the HW used to detect a capacitance shift, determining a touch is primarily a software challengemTouch Capacitive Touch Algorithm 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide13Firmware AlgorithmThe algorithm is independent of the HW ( SR Latch, CSM or CTMU)Compare

16、latest measured value with slow moving averageAutomatically adjust for environmental changesTrip level is relative to moving averageSensitivity remains constantOther functions implemented the same as normal buttons:Debouncing Touch and release Etc.TimeFrequencyAbsolute AverageSensor Touched 2008 Mic

17、rochip Technology Incorporated. All Rights Reserved.Class TitleSlide14Sensor ReleasedFloating Trip levelImplementation* Coming soonFW: Turn-key solution but with some limitations Library: Easy to integrate Cap Touch in an application Source Code: Designer has full controlMicrochip has the most flexi

18、ble offer 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide15FWLibrarySource CodeCompetitor 1YesN/AN/ACompetitor 2YesYesN/AMCHPYes*YesYesAvailable Resources 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide16mTouch design center: - Basic Overview

19、 of operationWebinar onlineAN1102 - Hardware and Layout of sensorsWebinar onlineAN1103 - Software Techniques for detecting buttonsAN1104 - How to get more buttons? AN1171 - Using the CSM with PIC16F72X AN1202 - Capacitive Sensing with a PIC10F CTMU Ref ManualDemo Boards Available TodayDM164125: PICD

20、EM Touch Sense 1PIC16F with S/R latch module Examples of keys and sliders PICkit Serial Analyzer$139.99DM240011: PIC24F Starter KitFeatures PIC24FJ256GB110with 256KB FlashUSB OTG And CTMU forcapacitive touch$59.98 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide17MCHP & C

21、hemtronics Multi-FunctionAdvanced Engineering Demo Board16-button(Multi-key, PIC16F727)4-button(Slider Key, PIC16F690)HighlightSingle-button(Mchp logo key, PIC10F206)8-button(Wheel Key, PIC16F726)Single-button(PIC10F206)Kit includes demo board, CD ROM (schematics, gerbers, BOM, source code) and user

22、s guide Combine all of Microchip capacitive mTouch solution : Single, 4-button, 8-button, 16-button Use Grid sensor pad to transmit the LED light Use Gasket to transfer capacitance in case of big air gap between front panel and sensor pad Various sounds Touch Microchip logo button first to make all

23、blocks operate Onboard PIC Microcontrollers can be reprogrammed using PICkit 2 or MPLAB-ICD2 Allow the user to monitor the capacitance on each button using PICkit Serial Analyzer 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide18MCHP & TrueBeyond1 button Capacitive Advanc

24、ed Engineering Demo BoardPICkit 2 or ICD2Connector1-button(PIC10F206)LED LightingUSB Power ConnectorHighlightKit includes demo board &, CD ROM (schematics, gerbers, BOM, source code) Minimize the capacitive board : single buttonCan be used as One Key touch sensor or a Proximity sensor Use PIC10F206

25、+ a diode + a resistor Onboard PIC Microcontrollers can be reprogrammed using PICkit 2 or MPLAB-ICD2 2008 Microchip Technology Incorporated. All Rights Reserved.Class TitleSlide19Basic steps to design mTouchStep1 (Select Device) 1-button = PIC10F206 4-button = PIC16F690 8-button = PIC16F726 or PIC16

26、F723 16-button = PIC16F727 or PIC16F724Step2 (Understand basic operation of mTouch) RTC training Visit mTouch design center: Refer to AN1101 - Basic Overview of operationStep3 (Design Hardware and PCB) Refer to the Gerbers of reference boards Refer to the AN1102 - Hardware and Layout of sensorsStep4

27、 (Program the monitoring codes depends on # of buttons) Include I2C Communication with PICkit Serial Analyzer to monitor the sensitivity levelStep5 (Install mTouch Diagnostic Tool ) Install PICkit Serial Analyzer and mTouch GUI interface tool software(mTouchSDKInstallerVer2.0) 2008 Microchip Technol

28、ogy Incorporated. All Rights Reserved.Class TitleSlide20Basic steps to design mTouchStep6 (Monitoring sensitivity level) Select Slave Address (PIC16F726 : 0 x42, PIC16F727 : 0 x52 ) and monitor the sensitivity level of eachbutton Each touch pad is represented by its own individual gauge This adjusta

29、ble gauge can be used to analyze functional characteristics of the associated pad Find the levels of touched pad and untouched pad and threshold level Refer to mTouch Users Guide (DS41346A) and AN1103 - Software Techniques for detecting buttonsStep7 (Adapt the adjusted value to the application) Change the a