TASK 8 | TESTING IDEAS

Task: Traffic Light Control at an Intersection

Goal: Control the traffic lights to switch between red, yellow, and green at timed intervals.

Sample Block Code Logic:

Step 1: Set Up Your Workspace

• 1. Open the Lego Spike software on your computer

• 2. Create a new project and name it "Smart Traffic System."

Step 2: Connect and Configure the Sensors

• 1. Connect a Colour Sensor and a Distance Sensor to your Lego Spike hub.
  The  Colour Sensor will detect emergency vehicles (you can use a specific colour, like red or blue, to represent these).
  The Distance Sensor will detect the presence of vehicles or public transport at the intersection.

• 2. Attach the sensors to your model at the appropriate positions where they can detect traffic.

Step 3: Initialise the Sensors and Variables

• 1. Drag a ‘When Program Starts’ block from the "Yellow" category to the workspace.

• 2. Initialise the sensors by dragging and connecting the appropriate blocks:
  For the Colour Sensor: Use a block like "Set colour sensor mode" and set it to "Colour."
  For the Distance Sensor: Use a block like "Set distance sensor mode" and set it to "Centimetres."

• 3. Create Variables to track the state of the traffic lights (e.g., `currentLightState`).

Step 4: Continuous Monitoring with a Loop

• 1. Drag a ‘Forever’ loop from the "Control" category and place it under the "When Program Starts" block.

• 2. Inside the loop, add a block to continuously check the sensors:
  Use a block like "If...then" to create conditions based on what the sensors detect.

tep 5: Detect Traffic Types and Prioritise

• 1. Detect Emergency Vehicles:
  Inside the `If...then` block, add a block to check if the Colour Sensor detects your chosen colour (e.g., red for emergency vehicles).
  If it detects the colour, **set the traffic light to green** for the emergency lane by activating a motor connected to the traffic light.
  Add a `Wait` block to allow time (e.g., 10 seconds) for the emergency vehicle to pass.

• 2. Detect Public Transport:
  Add an `Else if` block below the first condition.
  Inside it, check if the Distance Sensor detects a vehicle within a certain range (e.g., less than 10 cm).
  If it does, **set the traffic light to green** for public transport and use a `Wait` block for a shorter time (e.g., 8 seconds).

• 3. Handle Regular Traffic:
  Add another `Else if` block.
  Inside it, check if any other vehicles are detected.
  If so, set the traffic light to green for regular traffic and use a `Wait` block for 5 seconds.

• 4. Allow Pedestrians to Cross:
  Add an `Else` block at the end.
  If no vehicles are detected, set the traffic light to green for pedestrians and allow them to cross for a few seconds (e.g., 7 seconds).

Step 6: Test and Refine

• 1. Run the program*by pressing the play button.

• 2. Observe how the traffic lights change based on the sensor inputs.

• 3. Adjust the timing or sensor thresholds if needed to ensure smooth operation.

Step 7: Save Your Work

• 1. Save your project by clicking on the save icon in the Lego Spike software.

• 2. Give it a meaningful name like "Smart Traffic System."