•  Develop preliminary software for Raspberry Pi (3) and (3A) to:
    • Pass DCC++ commands from the laptop (4) to the Arduino (2) and return status from the Arduino to the laptop.
      • USB/internet interface between PC (4) and Raspberry Pi (3A)
      • USB interface between Raspberry Pi (3A) and (3)
      • USB interface between Raspberry Pi (3) and Arduino/DCC++ BaseStation (2)
    • Accept commands from the laptop to control the servos/semaphores.
      • Design signal control commands/response between the PC (4) and Raspberry Pi (3)
      • Extract signal control commands from stream coming from PC
    • Accept commands from the laptop to Raspberry Pi (3A) to manage turnout sensors
      • Extract sensor control commands from stream coming from PC
      • Add/update/delete the association between turnout sensor IDs and GPIO pins
      • Report stored sensor IDs
      • Store/delete associations
      • Report to the laptop (4) the status or changes in status of the turnout sensors.
    • In lieu of a "FanShim" for cooling, design and install a Raspberry Pi (3) fan
      • Design fan mounting to cool Raspberry Pi CPU to avoid clock throttling
      • Use CPU temperature and/or frequency to trigger fan control
      • Add push button to control fan
      • Add Fan/temperature/frequency status to unicorn HAT display
    • Modify Unicorn HAT HD SPI library to use two select lines and two Unicorn HATs (3)
  • Add the Train Thing Simulator on the Website
    • Update/fix software
    • Build the "Quick Start" Video
  • Install semaphore signals and control servos
    • Design control servo mounting brackets and linkage
    • Manufacture brackets and parts
    • Install semaphore signals as they become available.
  • Add turnout status sensors
    • Design brackets to hold and adjust turnout feedback sensors
    • Build and install brackets
    • Design/build custom Raspberry Pi (3A) HAT/Bonnet to interface 24 GPIO pins and sensors.
    • Build cabling.