See https://hackaday.io/project/7646-ble-wasdmechanical-keyboard for build instructions!

I created a wireless mechanical keyboard using an arduino and BLE. I love the feel of a mechanical keyboard but I hate the wires. So I made it wireless.

This was a great project because I had never used bluetooth or BLE before. Nor had I used the PS2 protocol. It was a fun little project. Now I have very clean looking desk.

Gamers may freak out because this is a slap in the face for low latency. However, I am coder. As long as my eyes can't tell then I don't care. I just want a professional looking, nice feeling keyboard for coding and a wireless WASD fits that description.

1 × WASD Code Keyboard (Or any PS2 keyboard)

https://www.wasdkeyboards.com/index.php/products/code-keyboard.html

1 × Bluefruit LE micro

https://www.adafruit.com/product/2661

1 × Trinket lipo backpack

https://www.adafruit.com/products/2124

1 × USB Bluetooth 4.0 module

https://www.adafruit.com/products/1327

2 × 3.7v Lipo Battery(Any size you want)

https://www.adafruit.com/products/328

1 × Micro USB

https://www.adafruit.com/products/1826

1. Solder the 500mah jumper on the trinket backpack for batteries larger than 500mah
2. (Optional) Cut the switch trace on the trinket backpack and solder a micro switch between the two contacts. See https://learn.adafruit.com/adafruit-pro-trinket-lipoly-slash-liion-backpack for more details
3. Solder the trinket backpack to the Bluefruit micro
4. Solder the micro USB power connections to ground and 3.3v on the Bluefruit Micro
5. Solder the Data ( + ) pin(PS2 clk) of the micro USB to pin 2 on the Bluefruit micro
6. Solder the Data ( - ) pin(PS2 data) of the micro USB to pin 3 on the Bluefruit micro
7. Solder all batteries in PARALLEL to the trinket backpack
8. Plug the micro USB into the keyboard and double stick tape the electronics

• Battery life depends on the size of your battery, power consumption of your keyboard, and the power level of your bluetooth
  • I haven't tested my battery life with 6000mah battery nor have I measured the power consumption( multimeter broken :( )
  • I can run a 12 hour work day with stock bluetooth power settings and medium backlight with no problems
• You can charge the keyboard through the micro USB on the bluefruit.
  • I usually charge mine when I leave work

1. Download my git repo
   • https://github.com/djnugent/BLE_WASD
2. Install the proper drivers
   • https://www.adafruit.com/datasheets/PJRC%20CDC%20serial_install.zip
3. Download the adafruit Bluefruit library
   • https://github.com/adafruit/Adafruit_BluefruitLE_nRF51/archive/master.zip
   • Add to your arduino library
4. Add Adafruit board support in Arduino IDE
   • https://learn.adafruit.com/add-boards-arduino-v164

1. Download the adafruit app
   • https://learn.adafruit.com/bluefruit-le-connect-for-ios
   • https://play.google.com/store/apps/details?id=com.adafruit.bluefruit.le.connect&hl=en
2. Follow this procedure
   • https://learn.adafruit.com/bluefruit-le-micro-atmega32u4-microcontroller-usb-bluetooth-le-in-one/dfu-bluefruit-updates
   • REMEMBER TO GROUND THE DFU PIN

1. Open this project in the Arduino IDE
2. Select Bluefruit Micro as your board
3. Select the proper serial port
4. Click upload

1. Hit shift + ctrl + esc on your MODIFIED keyboard
   • This will reconfigure your bluetooth module for keyboard use
   • Bluetooth is now named "BLE_WASD"
   • Do this again if your keyboard ever stops working randomly
2. Connect your keyboard to your computer or phone
   • I have only had luck with Windows 10(it was able to solve the funky driver errors from the adafruit bluefruit module)
   • Windows 7 was a no go
   • Windows 8 is untested
   • Android only works upon first pairing
   • Apple products untested

• This code will work with any arduino and bluefruit module, you just need to change the pinouts and stuff.
  • https://learn.adafruit.com/introducing-the-adafruit-bluefruit-spi-breakout
  • https://learn.adafruit.com/introducing-the-adafruit-bluefruit-le-uart-friend
• This code supports 100% of the PS2 receiving protocol(one way communication) and has some extra features for a WASD keyboard(media keys)
• Use the special_functions( ) function to do custom things with your keyboard. Like make a T9 number pad.
• You can change the power output of the Bluetooth module to increase range or save battery