1. Prototyping Home Automation Concepts
Class 2: Home Security Basics
December 13, Don Wilcher

2. Home Security Basics Topics Home Security Elements
Example Systems and Devices: A Maker’s Perspective
Hands-On Project: Ultrasonic Detection and Alarm device

3. Home Security Elements
A Do It Yourself (DIY) home security system should consist of the following elements.
A Central Monitoring System:
a) verifies all alarms before dispatching authorities
b) Communications can be via land line, celluar, Internet or combination.
Source:

4. Home Security Elements…
c) Optional two-way alarm verification enables monitoring personnel to listen in—only in the event of an alarm—and communicate with residents to verify the alarm before dispatching.
Motion Sensors
a) provide a second line of defense if an intruder gets past the door/window sensors.
b) Some sensors are referred to as PIRs, because they use passive infrared technology to detect the heat emitted by an intruder.
c) serve as occupancy sensors. A home security system dealer can program the system to turn off lights in the room if there is no activity for 5 minutes.

5. Home Security Elements…
Sinage
Window stickers and yard signs tell would-be intruders: Don’t even think about trespassing here.
Security Control Panel
As the hub of the home security system, the security panel
communicates with all of the devices including sensors (wired and
wireless), sirens, keypads, central monitoring station and the Internet.
Door/Window Sensors
a) The first line of protection, door/window sensors (sometimes
called “contacts”) detect the opening of doors and windows.
b) A system can be programmed to sound a chime when a door
or window is opened in an unarmed mode.

6. Home Security Elements…
Sirens
a) Most systems have one tone for a burglar alarm and another tone for fire.
b) Consider a system that also provides voice feedback so it can annunciate the specific issue: “Intrusion, master bedroom window.”
c) A good system will have a siren time-out feature, typically 15 minutes, in the event the system should go off accidentally.

7. Home Security Elements…

8. Question 1
Motion Sensors provide a_____ line of defense if an intruder gets past the door/window sensors.

9. Example Systems and Devices: A Maker’s Perspective
Basic latching alarm circuit
The circuit can be used for a wide range of simple burglar or fire alarms as well as a for portable travel alarms.
Source:

10. Example Systems and Devices: A Maker’s Perspective…
PIR Sensor based Security System

11. Question 2
Identify the basic circuit.

12. Example Systems and Devices: A Maker’s Perspective…
Fire Alarm circuit
Source:

13. Example Systems and Devices: A Maker’s Perspective…
Fire Alarm circuit: Low Temperature Detected

14. Example Systems and Devices: A Maker’s Perspective…
Fire Alarm circuit: High Temperature Detected

15. Example Systems and Devices: A Maker’s Perspective…
Window/Door Sensing:
How Does a Reed Switch Work?

16. Example Systems and Devices: A Maker’s Perspective
Window/Door Sensor: Window/Door Closed
S1= Reed Switch

17. Example Systems and Devices: A Maker’s Perspective…
Window/Door Sensor: Window/Door Open
S1= Reed Switch

18. Question 3
The electronic symbol shown slide 10 and identified as U1A is
a buffer
an operational amplifier
a common emitter amplifier
None of the above

19. Hands-On Project:
Ultrasonic Detection and Alarm device

20. Hands-On Project Ultrasonic Detection and Buzzer-Alarm
Project Objectives:
Learn about the GrovePi+ Shield Architecture
a) Review of the circuit schematic diagram
b) Review of electrical connectors and ports
Build a ultrasonic sensor actuated buzzer-alarm

21. Hands-On Project…
GrovePi+ Shield: Partial Circuit Schematic

22. Question 4
What port is used to attach the Ultrasonic to GrovePi+’s Atmega328p microcontroller?

23. Hands-On Project… Source:

24. Hands-On Project… Source:

25. Hands-On Project… GrovePi+ Shield: Electrical Connectors
Circuit Schematic Diagram

26. Ultrasonic Detection and Alarm Device Block Diagram
Hands-On Project…
Ultrasonic Detection and Alarm Device Block Diagram

27. Ultrasonic Detection and Alarm Device Parts:
Hands-On Project:
Ultrasonic Detection and Alarm Device Parts:
GrovePi+ Board & Raspberry Pi
Piezo-Buzzer and 4 Conductor Jumper wire
Ultrasonic Sensor and 4 Conductor Jumper wire

28. Ultrasonic Detection and Alarm Device Wiring Diagram
Hands-On Project…
Ultrasonic Detection and Alarm Device Wiring Diagram

29. Hands-On Project…
Project Build Complete

30. Hands-On Project…
Ultrasonic_And_Relay Python Code

31. Hands-On Project… https://github.com/DexterInd/GrovePi
Ultrasonic Detection and Alarm Device Python Code can be obtained from Dexter Industries github site:

32. Question 5
In the Ultrasonic_And_Relay.py code, there is a variable assignment name used to control pin 2 for the Piezo Buzzer. Write a new variable assignment name to reflect the actual device wired to pin 2.

33. Hands-On Project…
Open LXTerminal on the Raspberry Pi desktop and type the following directory and file commands to run the Python Ultrasonic_And_Relay code.

34. Hands-On Project…
Congratulations!