Quick Key Adapter, 10 Button HID Keyboard

This Instructable covers creating a USB connected Human Interface Device Keyboard that has 10 button inputs which are mapped to key combinations in the firmware. Key combinations can be quickly accessed without using the keyboard which may be inconvenient to use. Such as with a MAME or similar machine where the keyboard may be stored or inaccessible or certain keys may be used frequently but aren't mapped to any of the arcade buttons. 

Such as: Alt+F4 for Close Program, Windows+D to Show Desktop, Minimize Window, Maximize Window, Multiple Launch Program or Emulator, Alt+Ctrl+Del, Coin Buttons for players 1 and 2, 

The custom hardware(circuit) is based on Microchip Solutions sample "USB Device HID Keyboard" firmware for the Low Pin Count USB Development Kit which uses a 18F14K50. The development kit is not required to recreate this as included here is a schematic, PCB layout and firmware to build one from scratch.

It does not require any external power supply, it draws from the USB host. All the keycodes are set in firmware and are for Windows based OS's, additional OSs could be used but the keycodes would have to be changed in the firmware.

This device is similar to U-HID or similar but with a lot less keys and no computer software to change or set key combos.

If someone would like to send me key codes for a different OS, I will put together the firmware and post it to this Instructable.

Included in the ZIP below is PCB Layout, Schematic, diagrams, MPLAB project files, HEX file, readme, and the datasheet. Or you can view the HID Quickkey USB Adapter Datasheet


UPDATE: The included Hex didn't seem to work, I have uploaded I new HEX that I am sure works. Version 2 Firmware with the fixes and updates will be uploaded soon.


DISCLAIMER: Recreate this project at your own risk. There is always risks when building your own electronics, be careful. Damage to the computers USB bus is possible, but not probable when everything is built correctly.

Step 1 Parts and Supplies

Complete Kits including the programmed PIC is available in my Store

Basic Kits including the programmed PIC, without buttons and wire are also available.

Parts:

• PIC18F14K50 - DIP package, Buy One Programmed
• 2x 10k 5 bused resistors Like This
• USB Type B Socket
• 12 mhz Oscillator, series*
• 0.1uF disc Capacitor
• 220nF disc Capacitor
• 4 pin Header, such as Molex KK6410
• 4 pin Housing, such as Molex KK 6471
• 6 pin Header, such as Molex KK6410
• 6 pin Housing, such as Molex KK 6471
• Crimps, Molex KK 4809
• Wire, solid strand and stranded
• Printed Circuit Board or Perforated Proto board and solid strand wire
• 10 Normally Open Push buttons, board mount
• USB Type B to Type A cable(most devices such as printers use them) Buy One

*Normal crystal oscillator can be used, just add a 22pF capacitor from each OSC pin to ground.


Tools:

• Soldering Iron
• Wire Strippers
• Diagonal Cutters