1. Wireless Controlled PowerStrip
Shubham Pahadia
Austin Chu
Doni Tampubolon
Team 4

2. Goals and Benefits
Figure 1: Overall Project
Provide user with the ability to manage power status of outlets through a central hub
Modernize the ability of power tracking and consumption
Very low power consumption means low electricity cost: 0.12c per day cost
User Friendly installation method

3. Features
Smartphone application to allow hub control for easy manipulation and observation
Compact Design
Internal Switch Relay to control power to end load
Power Sensor Suite for all outlets to record power consumption
Low Power Usage
Large Memory Storage

4. System Overview
Figure 2: High Level Block Diagram

5. Figure 3: High Level Block Diagram (Detailed)
System Overview
Figure 3: High Level Block Diagram (Detailed)
Power Unit
Outlet Unit + Sensor Suite
Control Unit

6. Smartphone Application Design
Power Status Radio Buttons to turn outlets on and off
PickerView to decide which set of data you wish to see
Textbox to illustrate data being sent and receive data
TabView Controller for controlling individual Outlets
Figure 4: Smartphone Interface

7. Bluetooth Connection Module: AdaFruit Bluefruit LE SPI Friend (BLE)
Figure 5: Smartphone-Bluetooth Interface
Module: AdaFruit Bluefruit LE SPI Friend (BLE)
Low Power Consumption: runs on 3.3V and mA (max) => 41.5 mW
Distance up to 5 meters
Transmits character data from Smartphone to MCU
Lower Power Usage compared to Wi-Fi Unit

8. MCU Control Figure 6: MCU Control Flowchart
Reads and sends SPI data from and to SD Card and Bluetooth
Sends Digital Signal to Relays
Receives Analog Signals from Sensor Suite
Low Power Consumption: runs on 3.3V and 4.16mA (max) => mW
Figure 6: MCU Control Flowchart

9. Sensor Suite Voltage Sensor: ZMPT101B
Low Power Consumption: runs on 5V and 2mA (max) => 10 mW
Senses up to 120V AC
Current Sensor: ACS726
Low Power Consumption: runs on 3.3V and 14mA (max) => 46.5 mW
Senses up to 20A

10. Relay System Power Supply from Regulator
Figure 7: Relay Design
Power Supply from Regulator
Controlled through Digital High and Low from MCU
Outlet Connection was through the Normally Closed Connection

11. Rectifier Design Used Variac to send AC Voltage
High Capacitors yielded a smaller ripple
Successfully outputted a constant DC output using Rectifier Design through connection with an Outlet
Figure 8: Rectifier Design

12. Flyback Design
Figure 9: Flyback Design
Initially planned on using PWM to control switching frequency
Moved to DC-DC controller due to isolation issues
Converted from 160Vdc to 5Vdc with plus- minus .8V
Bootstrap circuit provided initial power
Small design and cost effective vs other converters

13. Linear Regulator
Needed a 3.3V DC Supply to various components while flyback only provided 5V output
Regulated an output for safety in order to not break our sensitive units
Figure 10: Regulator Design

14. Conclusion Completed each individual component
Had difficulties integrating the power supply to the entire project
Completed our initial goal of a wirelessly controlled relay extension cord for smart home purposes

15. Learning Experience
Challenging but rewarding experience when we had individual components work
Managed to get a better understanding of the design process, teamwork and communication skills
Developed new skills in programming, circuit design, power systems, and engineering practices

16. Future Hardware Development
Integrate Power Supply System with Device Components
Increase number of outlet outputs
Improve on Flyback Design to utilize a PWM instead of controller for lower power usage
Improve Soldering and Manufacturing

17. Future Software Development
Implement a log-in feature for smartphone application for security purposes
Implement encryption on data for security purposes
Improve GUI for creating a more polished product
Implement a greater variety in the data stored and displayed

18. SWOT Analysis Strengths: Weakness: Threats: Opportunities:
Cost effective
Space Efficient
Low Power Consumption
Weakness:
Inherent Safety Issues
AC-DC Converter implementation
Threats:
Prior Integration in new homes
Niche Market
Susceptible to Security Breakthroughs
Opportunities:
Power Management
Software Expansion
Need for smartHome purposes

19. Thank You and Acknowledgements
Special Thanks to Jackson Lenz for assisting us throughout the entire process
Thanks to Machine Shop for PCB and Housing construction
Thanks to Peers for their reviews and assistance throughout the project
Thanks to TAs for their guidance on various questions and safety
Thanks to professors for teaching proper engineering practices and the learning opportunity
Thanks to our audience for letting us share our experience and journey through our capstone project as undergraduate students at U of I