2 Kit Contents 3ft USB A to mini-B 5pin 28/28AWG Cable USB Keypad w/ bumpersUSB Keypad Block Diagram3ft USB A to mini-B 5pin 28/28AWG CableLumvatech Company Profile Insert
3 Crystal Free USB Keypad with mTouch Demonstration HighlightsAll features driven by single device – PIC16F1459Crystal free USB operation18 touch buttons using Capacitive Voltage Divider (CVD) techniqueLED backlight with proximity sensing ON and auto power OFFUSB HID interfacePlug and playLow cost lightweight designAudio feedback using the piezo buzzerDevelopment Made EasyLow-cost development experienceStart with the FREE downloadSchematics & ‘C’ source codeEasily modified to your specific application needsDownload at
4 Crystal Free USB Keypad – Block Diagram PIC16F1459 device with USB, 9 Channel ADC, PWM, Active Clock Tuning, etc.USB powered deviceCurrent consumption < 100 mA
5 Matrix Key Design Uses mTouch CVD technique COLOUMN 0COLOUMN 2Key size 12mm*12mmUses mTouch CVD technique9 ADC channels - 5 rows * 4 columnsTwo columns are also used as proximity sensorsGuard ring to reduce parasitic capacitance on sensorsCVD application note••COLOUMN 1COLOUMN 3•••••ROW 0S1S2S3S4•••ROW 1S5S6S7S8•ROW 2S9S10S11S12••ROW 3••S13S14S15Guard••ROW 4S16S17S18Key size 12mm*31mmGuard ring 3mm away from sensors. Thickness 1mm.55
6 Lumvatech Graphics, Panel, Keypad PCB Top panel with graphics printed on it.12 side firing LEDs (6 on each side) provide backlighting.Panels are provided by Lumvatech. (www.lumvatech.com)
7 High level Firmware Architecture Application(keyboard.c)HID Function Driver(usb_function_hid.c)USB Device StackmTouch CVD StackLED and BuzzerFirmware IntegratesUSB Device StackmTouch CVD stackBoth the stacks are part of MLAMLA is freely downloadable at
8 Simplified Application Flow Chart main()Initialize USB, mTouch()AISRSend 0x00 to HostIs any valid mTouch key press detected?Is USB Device in Configured state?NoNoUSBDeviceTasks();YesYesIs Last USB transfer completed?mTouch_Scan();NoIs proximity Sensor press detected?NoLEDService();YesYesSend corresponding key to HostActivate KeypadTurn ON LED backlightEnd of ISRBuzzer BeepA
9 Audio Feedback When Num Lock is ON, buzzer beep frequency is 1000hz When Num Lock is OFF, buzzer beep frequency is 2500hzSlightly longer beep for Num Lock ON and OFFHold the Clear key for 2 Sec to turn ON/OFF the buzzer feedback. Hold the key until a longer beep is heard from the buzzer.
10 USB Keypad Summary All features driven by single device – PIC16F1459 Active Clock Tuning for crystal Free USBSaves as much as $0.15 by eliminating external crystalGuarantees 0.25% accuracy when connected to USB hostUSB HID interface – plug and playCapacitive touch sensing based on CVD technologyLED backlight with proximity sensing ON and auto power OFFSleek and low cost designEasily modified to specific application needsDownload schematics & code at:
11 Learn more…Visit us on the web:Quick start guideApplication note and ‘C’ source codeSchematic and board filesVisit us on the web:USB Development PlatformsUSB Reference DesignsUSB Application NotesUSB Products & Peripherals
12 Partner OverviewA leading provider of microcontroller and analog semiconductors, providing low-risk product development, lower total system cost and faster time to market. With an increasing focus on lighting applications, Microchip offers outstanding technical support along with dependable delivery and quality.A leading U.S. based manufacturer of ultra-thin backlighting that provides solutions from simple logo backlighting to complete user-interfaces. Lumvatech serves the medical, white goods, brown goods, and automotive industries with easy integration, fast speed to market, and high-quality lit products.