1. ECE 445 Smart Window Responding System
Group #8
TA: Zipeng Wang
Xuanzhen Cao
Jiaxi Nie
Zhichun Wan

2. Introduction
Open Window
Dust Storm
Rain
Temperature Rise/Drop

3. Objectives
1. Automatically close the window after detecting raindrops;
2. Automatically close the window after detecting an air
quality drop;
3. Automatically close the window after detecting a
significant temperature rise or drop crossing a preset
threshold
4. Instantly stop the window from closing after detecting
presence of human limbs or pets resting on rails.

4. Block Diagram

5. Block Diagram

6. Power Supply Module Power Supply
Overview
Functions:
12V supply to actuator
5V supply to sensors and microcontroller
Considerations:
5V supply must be stable
Implementations:
Connect 12V battery directly to Motor’s driver
Use voltage regulator to obtain 5V supply

7. Power Supply Batteries Battery Choice
8 AA batteries in series for 12V voltage source
AA battery: 1.5V each, 2875mAh capacity

8. Power Supply Voltage Regulator Design:
Use 3-Terminal Voltage Regulator LM317
Capacitor: Ripple rejection
Diode: Chip Protection

9. Power Supply

10. Power Supply Verifications Battery: 12.8V with new battery
11.7V after 5h operation
Voltage regulator:
5.07V stable

11. Sensing Module

12. Rain Sensor Input: 5V DC Output: Analog output to microcontroller
No rain: output high
Rain: output low
-25% of sensing board covered by rain
Sensor Driver: implemented on PCB

13. Rain Sensor Input: 5V DC Output: Analog output to microcontroller
No rain: output high
Rain: output low
-25% of sensing board covered by rain
Sensor Driver: implemented on PCB

14. Temperature Sensor Input: 5V DC
Output: Analog output to microcontroller
Analog Output: Linearly proportional to temperature
Range: 20~30°C
Error: <1°C

15. Temperature Sensor Input: 5V DC
Output: Analog output to microcontroller
Analog Output: Linearly proportional to temperature

16. Temperature Sensor Input: 5V DC
Output: Analog output to microcontroller
Analog Output: Linearly proportional to temperature
Range: 20~30°C
Error: <1°C

17. Dust Sensor Input: 5V DC Supply 5V DC LED Supply
Output: Analog output to microcontroller
Detection Accuracy: >80%
Delay: <5s

18. Dust Sensor
Light Emitter: LED →Light Pulse
Light Detector: Photodiode

19. Dust Sensor Input: 5V DC Supply 5V DC LED Supply
Output: Analog output to microcontroller
Detection Accuracy: >80%
Delay: <5s
Baseline

20. IR Sensor Input: 5V DC Output: Digital output to microcontroller
Detect infrared:
- No detection: output low
- Object detected: output high
Accuracy: >95%
Response Time: <1s
Detection Range: <30sm

21. IR Sensor

22. IR Sensor Input: 5V DC Output: Digital output to microcontroller
Detect infrared:
- No detection: output low
- Object detected: output high
Accuracy: >95%
Response Time: <1s
Detection Range: <30sm

23. IR Sensor Input: 5V DC Output: Digital output to microcontroller
Detect infrared:
- No detection: output low
- Object detected: output high
Delay: 3s

24. IR Sensor Input: 5V DC Output: Digital output to microcontroller
Detect infrared:
- No detection: output low
- Object detected: output high
Response Time: us

25. Microcontroller Overview Functions: Collect input signals from sensors
Output control signals to the H-bridge
Decision making for system behavior
Implementations:
ATmega328P chip
Programmed with Arduino bootloader

26. Microcontroller

27. Microcontroller

28. Check safety module reading
Microcontroller
Initalize
Poll sensors data
Check safety module reading
Make Decision
Send Signals to Motor

29. Microcontroller Design Threshold selection:
Temperature — up_limit: 28°C, down_limit: 20°C
Dust sensor — mg/m3.
Rain sensor — 900
Buffered thresholds to reduce glitches
A/D conversion in Arduino: Varduino = V/5.1 * 1024
Clock: external 16 MHz oscillator
LED blinking: timer interrupt signals (2Hz)

30. Microcontroller Verification(average):
Input signals accuracy <= 10mV
Output signals accuracy <= 20mV
Response time(average):
IR sensor ~ 18ms
Temperature sensor ~ 25ms
Rain sensor ~ 30ms
Dust sensor ~ 30ms

31. Actuator Module Overview Functions:
Drive the actuator based on control signals
Implementations:
Linear Actuator
Driver Circuit (H-Bridge)

32. Actuator Module Driver (H-Bridge) Considerations: 2 control signals
Design:
Control signal controls Q5,Q6
Q5 controls Q1,Q3
Q6 controls Q2,Q4

33. Actuator Module

34. Actuator Module Driver (H-Bridge) Verification: Open Close Motor (V) 11

35. Actuator Module Linear actuator Specs: Operating Voltage: 9 ~ 16V
Max extension length: 30cm
Stroke Speed: 1cm/s
Load Capacity: 750N (170LB)
Usage:
Mounting Brackets

36. Power Consumption

37. Future Work

38. Future Work Power Supply
Replace battery 120V AC input with AC/DC Converter

39. Future Work
Wireless communication between modules

40. Future Work
Sensor networks
IR sensor
Temperature sensor

41. Future Work
User Interface
Graphical User Interface(GUI)
SD Card

42. Future Work Environment Adapting Machine learning
Alternative microcontroller

43. Conclusion All functionalities realized 6 PCBs soldered and tested
LED matrix added
Future work

44. Acknowledgement
Special thanks go to our TA:
Bird

46. Q&A