ICT at key stages 1 and 2    (Year 6)

• Discuss with the class how a variety of cause and effect devices work, eg central heating, security lights, road lights, supermarket freezers. Talk about how the environment is monitored constantly to check if changes have occurred, eg when it gets cold the heating comes on, or street lights come on when it gets dark. Discuss the difference between a timed event and an event that occurs as a result of measuring physical change. Ask the children to identify three systems that use monitoring to control events. Ask them to write a simple desription of how each system might work.

• Remind the pupils of the simple procedure used to make a lightbulb come on. Explain that the computer is going to have an input device added to it - in this case a simple switch. When the switch is pressed the lightbulb will come on. The children will need to understand the concept of an endless loop - repeat forever - because the computer has to check continually if the switch has been pressed. Write a simple procedure with the children to produce this effect, eg

  repeat forever
  if Input 1 on then lamp
  end repeat
  where lamp is a simple procedure to turn on the bulb, wait two seconds and switch it off.

• Ask the class to work in small groups to check that the bulb always comes on when the switch is pressed.

• Repeat the previous lesson but use a light meter to monitor light and darkness. Ask the children to design a simple lighthouse using a bulb, a cardboard tube and a light sensor. Tell the children they are now going to make their lighthouse work.
• Ask the children to write a procedure to make the lightbulb flash every second. Ask the children to draw a diagram of their lighthouse and show where the wires are plugged into the control box. Allow them to test and amend their procedures. Now ask them to use the light sensor to make the sequence occur when it is dark and not when it is light.

• Discuss how automatic doors sometimes operate using pressure pads. Explain that when something comes in contact with the pads, they send a signal to a motor which opens the doors. When pressure is taken off the pads the the doors close. Describe the other input devices used to control doors, eg light beams and heat sensors. Ask the children to describe a system, draw a picture and then write two procedures to open and close a door. Allow the children to enter their procedures, test and modify them.

• Explain to the class that they are going to make a house security system with a floodlight and house lights that come on after dark and go off in the morning, a window alarm based on a magnetic switch, a door alarm based on a pressure pad and a burglar alarm with a loud buzzer and flashing lights.
• Ask the children to work in groups to build a model of a house with a variety of input and output devices attached. This could just be the front facade, built out of cardboard or other material. The house will need a floodlight and light sensor outside and lights at one or more windows inside. The front door will need a pressure pad under the door mat and the window will need a magnetic switch. Both door and window will need to open. There should be a coloured light and buzzer on the front of the house marked 'alarm'.
• Ask each group to write a sequence of instructions to switch lights on at night and off in the morning and for the alarms to sound if the door or window is opened. They should write separate sequences for each event, not try to combine them all. Ask them to record their programs, draw and annotate a diagram and describe the results.