2015-10-07 (W) Wrist Mounted Chording Keyboard

An OpenSCAD module was written which produced a bar with a half circle on one or both ends and holes. Shapes such as this have been convenient before so the module should save time. This module will be distributed if it is used in the final design.

A mounting platform was modeled to hold the emitter and receiver tubes by rendering three rounded bars. For a base a flat bar with two rounded ends was modeled at the origin [0, 0, 0]. Two smaller bars were modeled to form a slot where the emitter and receiver tubes could be placed and held on both sides. Holes were made in the vertical pieces to match with the hole in the tubes.

Model of wrist mount

A print was made and allowed to cool. Two nylon washers were placed on either side of the tab on the emitter/receiver tube and a bolt was placed through all three holes to make a hinge. The purpose is to be able to adjust the line of sight, LoS, so a precise threshold could be tuned when using the proximity switch.

Assembled unit

Wearing the device was simple. The long base was modeled so it could be slid under a watch band, wrist band, sweat band, bracelet, bracer, or similar wrist-worn accessory. If a sweat band, or similar cloth, was used Velcro could be used between the base and wrist band to keep it steady. In the photo a wrist-worn fitness tracker was used.

Temporarily worn. Wrist shown flexed to ensure range of motion

Downloadable Files:
To do:
  • Wrist mount
    • Terminal board
      • Input voltage
        • USB
    • Make base for keyboard
      • Spacers 
      • Magnet mounts
    • Integrate:
      • Enclosure for each controller
        • Potentiometer access
      • Activation switch
    • Debug 
    • Test
    • Refine
    • Repeat
  • Write instructions
    • Compress and link to all files
      • OpenSCAD files
      • STL models
      • Arduino code 
    • Make diagram with every part labeled 
    • Schematic for servo controller

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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All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

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2015-10-05 (M)