Iterative Design

Iterations

Iteration 1 - Proof of concept - Dispense coins on command

• ✅ Restore the Master programmer I accidentally burned
  • ✅ Mill it
  • ✅ Solder it
  • ✅ Program it
• ✅ Program SAMD11D14AS board
  • ✅ Controlling Servos
    • ✅ Find how to program it
      • ✅ via programmer
      • ✅ via USB
    • ✅ Find how to make it set pins to HIGH LOW
    • ✅ Find which pins support PWM
    • ✅ Find how to use PWM to control Servo using D11D (which does not support the Servo Library)
  • ✅ Receiving Inputs from UI
    • ✅ Receive commands from SerialUSB (computer serial monitor, in iteration 1)
  • ✅ Acting on UI commands
    • ✅ connect incoming Serial commands to outgoing Servo Movements
• ✅ 3D print Coin holders
  • ✅ 10 cents
  • ✅ 20 cents
  • ✅ 50 cents
  • ✅ 1 eur
  • ✅ 2 eur

Iteration 2 - Add more basic functionality and start packaging it nicely

• ✅ Arduino
  • ✅ Create simple web Java app for the RaspberryPi
  • ✅ Make RaspberryPi send Serial commands to board
  • ✅ Add Screen to RaspberryPi
  • ✅ Display website on RaspberryPi Touchscreen
• [ ] System integration and packaging
  • ✅ Design simple box that contains all of the components
    • ✅ It can hold the coin acceptor
    • ✅ It can hold the touchscreen, in the correct orientation
    • ✅ The coins that fall from the coin acceptor are direct down the coin selector ramp
    • ✅ There is a coin selector ramp with the right coin sizes
      • [ ] And it works properly and consistently
    • ✅ There is a coin ejection ramp that collects coins as they are ejected
    • ✅ The ejection ramp deposits coins outside of the case
    • [ ] There is a coin collection tray outside of the case to receive the coins as they are ejected
• ✅ Coin acceptor
  • ✅ Program it so it recognises and allows pass-through for all supported coins:
    • ✅ 10c (code 1)
    • ✅ 20c (code 2)
    • ✅ 50c (code 3)
    • ✅ 1eur (code 4)
    • ✅ 2eur (code 5)
    • ✅ reject all other coins (default behaviour for unknown coins)
• [ ] Coin acquisition funnel
  • ✅ Prototype a coin extension funnel that reaches up to the coin selector ramp and does not allow coins to fall outside
    • [ ] Each of the coin cylinders has an extension funnel
    • [ ] Bonus, it also provides larger holding capacity to each of the cylinders
• [ ] Coin Ejection Funnel
  • [ ] 3D print the ejected collector funnel (lower ramp)
• [ ] Expand electronics:
  • ✅ Create a secondary board to connect all the servos together
    • ✅ Design the board
    • ✅ Mill it, solder it
• ✅ Program SAMD11D14AS
  • ✅ To control all 5 Servos concurrently
  • ✅ To parse commands for each of them
  • ✅ Wire PWM servos
• ✅ System Integration
  • ✅ Prototype a case to contain all the moving parts
    • ✅ Security is not a concern (the touchscreen alone is probably more valuable than the coins inside the machine!)
    • ✅ Design
    • ✅ Cut it
    • ✅ Assemble it
    • ✅ Reinforce it
    • ✅ Wire AC power to feed all the components
    • ✅ Cable management
      • ✅ Touchscreen to Arduino
      • ✅ Arduino to Board
      • ✅ Board to Servo Driver
      • ✅ Servo Driver board to 5 Servos
      • ✅ Power to Arduino and Touchscreen
      • ✅ Power to board and Servos
  • ✅ Package and integrate the 2 boards into the case so they dont flail around
  • ✅ Embed coin acceptor into the side of the case

Iteration 3 - Detect and sort incoming coins

• [ ] Program D11D14AS board
  • [ ] Find how to receive SERIAL from Coin Acceptor
    • [ ] Wire Coin commands to stateful mode
  • [ ] Persistence
    • [ ] Store coin state (number of coins for each denomination) in EEPROM so it survives power loss
• [ ] Have a mechanism to detect coins
• [ ] Have the board report coin status (a count for each type of coin) via serial
  • [ ] Have the website display this count
  • [ ] PULL information: Have the UI frequently check coin status (once per minute) to update the display
    • [ ] Bonus - PUSH information: Have the board notify the UI whenever a new coin is inserted (instead of polling)
  • [ ] Have the UI smartly control the coin distribution and autonomously decide how the change will be given if there are low/no coins of one type (eg. give 1 eur as 1x1 eur coin, or as 2x50 cent, or as 5x20 cents, etc…)