TRAFFIC LIGHTS by Paul Long, Fairfax School

This exercise looks at controlling a set of Traffic Lights using a Smart Box.

Notes
Click on the Play button to see the traffic lights working automatically. Notice how whilst one set of traffic lights is going through its sequence, the opposite set of traffic lights stays on Red to stop any traffic from moving.

The traffic lights are connected to a Smart Box which is connected to a PC so that the computer can control the lights. The Smart Box has a set of output ports that the lights are connected to. As the Traffic Lights go through their sequence, notice how the Output Ports light up to show you which ports are connected to which lights. Notice that if 2 or 3 lights are on at once then 2 or 3 ports are activated at once as well.

Now you can try this out for yourself. Click the Try It button. Click on the Output Ports at the bottom of the screen. As you click on the Ports you should see the traffic lights turn on and off. You can activate as many or as few ports as you like. What happens when you click on Ports 3 and 4?

If you have a Smart Box with a Set of Traffic Lights and a program similar to Logicator then you can try this for yourself and make the real traffic lights work.

Support Notes
This is an automated set of 2 traffic lights working together. It is suitable for students in KS 2/3 studying Control as part of ICT.

The first screen entitled "Traffic Lights Working Together" allows the student to press play, pause or stop to look at how 2 sets of traffic lights work together. It assumes that the traffic lights are connected to a Smart Box using the following Output Ports:

0 Green (Set A)
1 Amber (Set A)
2 Red (Set A)
5 Green (Set B)
6 Amber (Set B)
7 Red (Set B)

As well as being able to see the traffic lights work in sequence, students can see the output ports that are being used for each light.

By clicking on the Red "Try It" button, students can turn on individual lights themselves by using the Output Ports. Clicking on Ports 0-2 or 5-7 will turn the lights on or off. Clicking on Ports 3-4 will give an error message informing the student that the ports are not connected. Clicking on the Automatic Button will allow the student to see the lights working in sequence again.