Software is required for a simple house burglar alarm system.

House Burglar Alarm Specification

A house has two rooms each of which have a PIR motion sensor. Each and every room has a security light. There is also a PIR sensor outside the front door, which becomes active when it is dark outside. There is a security light outside the front door. The security lights are switched on, and an audible alarm sounds under certain conditions.

If the outside PIR is triggered (i.e. it is dark, and motion is detected), an outside security light is switched on for 20 seconds. Any room sensor activated will trigger the light for (only) that room for 10 seconds. Both room sensors activated within 10 seconds will set off the audible alarm continuously.

The only way to stop the audible alarm is to input a correct PIN. If the correct PIN is input, the alarm system is de-activated, and becomes dormant (ready for further burglar detections). If an incorrect PIN is entered, a ‘first warning' is provided on an LCD panel.

If a further incorrect code is entered, the alarm remains on, the outside light flashes, and a message is sent to the police station. Entering the correct code at any time that the audible alarm is on will de-activate the alarm.

The STD shown in Figure is intended to reflect this requirement specification. Figure shows the hardware to be used for the implememntation and testing of the code.

Tasks. For the specification given:

1. Produce a Flowchart

2. Produce a working program

a. uses sensible labels in code, and is easy to read

b. uses correct inputs

c. generates correct LED outputs

d. generates correct LCD outputs

3. Produce report, presenting all above, readable to software/hardware engineer

4. A demonstration of the working program.