• tips
  • give students a wiring diagram (or fritzing)
  • give students a sample program that turns all lights on (or is a pattern) so they can test wiring before coding (examples/light_test.ino)
• suggestions
  • need to cover enum, switch, delta timing, fsm
  • give students wiring diagrams
  • give students starting code that has light test and base code for starting project
  • lecture: switch
  • lab: start with delta timing to blink lights in one direction
  • lecture: FSM and enum
  • lab: draw out different states for one direction + pedestrians
  • lab: students code state transition
  • lab: students try to add second direction of traffic; make states diagram and code
• need to:
  • change solution code to use prevMillis
  • create wiring diagram
  • create basic slides on enum, switch, fsm, delta (this one might already be made)
• Role of loop()
  • calculate new state
  • output traffic signal LEDs based on state
  • independently flash walk signal (later)
• Stage 1: NS traffic light ==(do together with class)==
  • Lights transition from NSGreen, NSYellow, NSRed
  • States: NSG, NSY, NSR
  • Duration:
    • NSG, NSR = GO_TIME (5000)
    • NSY = TRANSITION_TIME (1000)

State	NS Stoplight
Traffic Flows	Green
Traffic Stopping	Yellow
Traffic Stopped	Red

• Stage 2: add pedestrians
  • Lights transition from NSGreen, NSYellow, Ped Walk, Ped Don’t Walk
  • States: NSG, NSY, PED, PEDDW
    • NSR is replaced by two new states for pedestrians
  • Duration:
    • NSG, NSR, PED = GO_TIME (5000)
    • NSY, PEDDW = TRANSITION_TIME (1000)

State	NS Stoplight	Pedestrian Light
NS Traffic Flows	Green	Don’t walk
NS Traffic Stopping	Yellow	Don’t walk
Pedestrians Go	Red	Walk
Pedestrians Stopping	Red	Don’t walk

• Stage 3: add don’t walk blinking
  • add another state timer for blink rate
  • Question: When should we blink?
    • DW light should blink in every state except PED
    • if we are after blink rate, then blink light

State	NS Stoplight	Pedestrian Light
NS Traffic Flows	Green	Don’t walk (flashing)
NS Traffic Stopping	Yellow	Don’t walk (flashing)
Pedestrians Go	Red	Walk
Pedestrians Stopping	Red	Don’t walk (flashing)

• Stage 4: add WE light
  • Lights transition from NSGreen, NSYellow, WEGreen, WEYellow, Ped Walk, Ped Don’t Walk
  • States: NSG, NSY, WEG, WEY, PED, PEDDW**
    • NSR is replaced by two new states for pedestrians
  • Duration:
    • NSG, NSR, WEG, PED = GO_TIME (5000)
    • NSY, WEY, PEDDW = TRANSITION_TIME (1000)

State	NS Stoplight	WE Stoplight	Pedestrian Light
NS Traffic Flows	Green	Red	Don’t walk (flashing)
NS Traffic Stopping	Yellow	Red	Don’t walk (flashing)
WE Traffic Flow	Red	Green	Don’t walk (flashing)
WE Traffic Stopping	Red	Yellow	Don’t walk (flashing)
Pedestrians Go	Red	Red	Walk
Pedestrians Stopping	Red	Red	Don’t walk (flashing)