Retropie-stuff

Game controller

Used hardware:

• Raspberry Pi 3 with 32 Gb SD-card with Retropie 4.2.
• mBed 1768 as controller
  Used to control all the buttons and the joystick.
  Furthermore, it handles the control button colors based on the emulator used.
  It handles the main power. Power will switch on with start pulse (green arcade button). And the relay board is started. It detects if the Raspberry Pi is shutdown (5V USB power gone) and will therefore shutdown the lights and the main power.
• 24 channel 12bit PWM LED driver
  Used to drive all RGB-LEDs for the control buttons and the white LEDs for the function buttons.
• Two channel relay
  Relay used to switch the main power with a small pulse. It is also possible to switch the main power off by the mBed. (E.g. if Raspberry Pi is shutdown.)
• All arcade stuff
  All the buttons, joystick and tools.

Fixes:

• Remove resistor in all function arcade buttons. PWM LED driver reduces the current to 15 mA.
• Change resistor in green arcade button (On-switch) to work at 5V instead of 12V.
• Replace the white LEDs by RGB-LEDs without resistors for all controller buttons.
  Function arcade buttons can stay white.
• Change USBKeyboard library (mBed) to connect during initialization without blocking! Otherwise system hangs until USB cable is connected.

Hardware design:

• 1 Joystick
• 6 arcade control buttons (A, B, C, X, Y, Z).
• 6 arcade function buttons (Start, Select, 1P, Menu, LeftTrigger, RightTrigger).
• 1 arcade button (green) used to start the system.
• 1 mBed LCP 1768 ARM Cortex M3 microcontroller.
• Raspberry Pi 3 with Retropie.
• 1 two channel relay board.
• 6 RGB-LEDs (common anode, 5 mm).
• 24 channel 12 bit PWM LED driver.
• Cables and connectors.
• A few USB cables ('Keyboard', Power detect and Raspberry Pi power).

Software design:

• Retropie runcommand-onstart and -onend
• Write USBKeyboard handler based on the USBKeyboard library from mBed, which will react on the button presses.
• Write serial handler to receive the emulator started or stopped.
• Write a real library for the 24 channel 12bit PWM LED driver with fast SPI (10MHz).
• Write an animator class to handle the lighting based on the system status. E.g. Startup, shutdown, screensaver, emulator:nes, snes, n64, amiga, etc.
• Write a power handler to switch on the main power during initialization. Switch main power off (after 30 seconds) if the Raspberry Pi looses USB power (on system halt).