2015-08-25 (Tu) Wrist Mounted Chording Keyboard

Mouse movement functions had been avoided to this point. Programming was written for the built-in USB mouse emulation. Mouse code was easy to implement once reasonable numbers were passed to it. Movement was essentially done by first taking a reading from the accelerometer (ADXL335) when the Far thumb button was pressed by itself then basing all movement off that initial location. In this way if the accelerometer was started at 35º on the X axis when the user moves the X axis to 36º (+1º) there is a small mouse movement to the right but if the user moves the X axis to 5º (-30º) there is a large movement to the left. Mouse movement would not be necessary for a desk mounted keyboard unless a joystick was attached. Due to the way to code has been written attaching a joystick should function without any modifications.

Macro shot of accelerometer

Once the USB mouse was functional programming was researched on Adafruit's tutorial on how to command the mouse. The tutorial was straight forward and easy to understand. Mouse movement was simultaneously working on a mobile phone (via Blutooth) and a laptop (via USB) after a few attempts. Variables were tuned to get usable mouse movement but user preferences will likely mean that users will changes these further.


Recent code for wireless keyboard with mouse movement

Downloadable Files:
To do:
  • Add mouse functionality.
  • Program changes:
    • Add mouse movement
    • Change mouse clicks to press and release according to buttons
    • Add random number generator
      • 0-1
      • 0-1000
      • Random equation followed by enter
  • Modify servos for continuous rotation.
  • Automate wrist mount.
  • Write instructions
    • Schematic

The rest of the posts for this project have been arranged by date.

First time here?

Completed projects from year 1.
Completed projects from year 2



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2015-08-24 (m)

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