2015-09-20 (Su) Wrist Mounted Chording Keyboard

10KΩ resistors were soldered to Vcc and the input terminals for the switches. These pull-up resistors provide a means of telling when a switch is open or closed by supplying a high signal to an input pin while nothing is connected and a ground signal when a switch is closed. As mentioned yesterday the pins which were also used for USB communication had to have resistors which could be removed for programming to take place. After reading some documentation it may have been unnecessary to attach a pull-up resistor to pin 3 where there was already a 1K5 resistor used for communication.

Program was simplified since there will be no need for another servo which deploys key levers. Before the program would understand it was in rear position and hold that position by observing a limit switch. If the rig fell out of that position the motors would kick in until the position was reacquired. If the hand switch was triggered the rig would move forward until the other limit switch was reached at which point the servos would stop and the deployment servo would activate for a moment. There was no need for some of that so the program was reduced. The hand switch toggles between two states. If the machine is in one state the servos activate one direction until they see a limit switch. If the machine is in the other state they run in reverse until they see the other limit switch. This routine was simpler to comprehend and simple to code.

Code will be posted when it works properly.

Resistors pulled out of terminals for programming

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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2015-09-18 (F)