TD-USB-02 interface with touchpad sensor board and WinAmp interface using PIC18F2550

TD-USB-02 interface with touchpad sensor board and WinAmp interface.

This is an example USB project showing how to interface a touchpad sensor (the AD7142ACPZ) with a standard XP/Vista computer.

The TD-USB-02 board with a PIC18F2550 communicates with:

  • the PC: USB 2.0 through a mini-B connector.
  • the touchpad sensor board: SPI over 8-wire flatcable.
  • PC WinAmp application controls (start/stop, next/previous track, volume up/down).

touchpad sensor board

Here are the technical specifications:

  • PC Win XP/Vista interface application with Visual C# 2008 Express: free download.
  • TD-USB-02 (green pcb on top) with PIC18F2550 USB HID setup.
  • TouchPad sensor board (047) with AD7142ACPZ.
  • USB Bus powered, no external power supply needed.
  • Activation of central wheel scrollpad and three buttons from any distance between 2-5mm.
  • Works from within a plastic enclosure, thickness up to 3-4mm.
  • Two LEDs (right above and under the centre button) blink when a pad is activated.
  • Custom command activated by top right button (example: “c:\windows\explorer.exe” )
  • TD-USB-02 software is 100% upgradable with a simple RS232 bootloader.
  • RS232 interface for raw data readings.
  • PCB Dimensions: TD-USB-02 40 x 41 mm or 1″57 x 1″61

These assembled boards are available from our online shop.

Source code (CCS C and Visual C#) can be purchased separately.


Sensor example Source code (CCS C) , sensor board pcb layout and schematics (Eagle) available. 

Last update: May 3, 2009.

TouchPad Board (047): Eagle PCB layout: 047_v005.brd  – Apr. 24, 2009.

 TouchPad Board (047): Eagle Schematics: 047_v005.sch  – Apr. 24, 2009.


 AD7142ACPZ: CCS c source code: touchpad_v01.c  – Apr. 24, 2009.

 TD-USB-02:Hex file: 047_v002.hex bootloading for the PIC18f2550  –  May 3, 2009.

 Windows interface application setup:  –  May 3, 2009. Written in Visual C# 2008 Express, compatible with Windows XP and Vista.


For more detail: TD-USB-02 interface with touchpad sensor board and WinAmp interface using PIC18F2550

About The Author

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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