2015-09-16 (W) Wrist Mounted Chording Keyboard

Connections for the servo controller were two servo motors and three switches. The method of connection was not important but a removable method with serviceable parts was desirable. Screw terminals for the switches and header pins for the servos were chosen. Each switch was given its own double screw terminal block even though all wires could have been attached with a pair of double screw terminal blocks. This should make connections easier than putting three wires under a single screw terminal and won't add significant area to the board. Terminals were arranged logically.

Connectors arranged on stripboard

 Connections were made on the bottom of the stripboard and terminals were soldered in place. Wires salvaged from Ethernet cable was used to jumper between connection points and to go between the connection board and Arduino. An ATTiny85 model was chosen due to its size and the number of connections. Initial programming was done on 2015-08-31 (M) but no testing was done. A map was sketched which showed the function of each terminal block on the board.

 Bottom of soldered board

All wires soldered and a map of each terminal block

After all soldering was done a razor saw was used to cut the board into a neat size. A saw with a narrow blade was preferable to one which would cut out a lot of material but an ordinary hack saw would work as well. Cutting a board can start on either side. Once the material is cut half way through it can be snapped on the score line. The board can also be cut all the way through using only the saw.

Wires were trimmed to a uniform length then the ends were stripped and tinned. Wires were soldered to the controller but no programming or testing was done. Length of the wires may need to be reduced to save space.

 Uniform length wires

Arduino soldered to connector board

Downloadable Files:
To do:
  • Wrist mount
    • Add limit switch mounts
    • Lengthen servo arms
    • Integrate:
      • Controller
      • High precision potentiometers for tuning servos
      • Servos
      • Enclosure for each controller
      • Limit switches
      • Activation switch
    • Debug 
    • Test
    • Refine
    • Repeat
    • Activation switch
  • Write instructions
    • Compress and link to all files
      • OpenSCAD files
      • STL models
      • Arduino code 
    • Make diagram with everything 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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2015-09-15 (Tu)