Sponsor: Beam Technologies Team Members: Andrew McGinnis - ECE Chad Carius - ECE Madison McClellan - ECE Behavior Monitoring Toothbrush

2 History of Beam Oral Healthcare Startup Formerly Inven, LLC Speed School Graduates

3 “Smart” Toothbrush Electronic Toothbrush that syncs data to a smartphone application Makes reports for users, dentists, and parents +

4 Operational Concept The Beam brush is used like a normal toothbrush Information is then uploaded every 50 uses Data is displayed on Smartphone

5 System Diagram

6 Development Process Overview 1)Explorer Development Board 2)Breadboard Prototype 3)Prototype PCB from U of L 4)Small scale production PCBs from Gold Phoenix

7 Microcontroller PIC microcontroller by Microchip PIC24F Family: 16 bit PIC24F16KA102 CPU speed: 16MIPS

8 Microcontroller Features RTCC (Real Time Calendar Clock) 2 UART 24 Digital I/O, 9 Analog Inputs Sleep mode: 25nA

9 Software Development MPLAB – Integrated Development Environment used to: 1)Program the PIC microcontroller 2)Write in C or Assembly 3)Software Debugging

10 Firmware Features Program: Record and Store time spent brushing Send and receive information to smartphone Manage Boost Converter, Capacitive Sensor, and LED Indicator

11 Firmware Program initializes the ports and registers RTCC EEPROM Capacitance Levels Analog to Digital Converter

12 Firmware The program then checks the capacitor for a brushing event If a there is a brushing event then the time and date of the event is stored It then waits for the end of the event and store the time

13 Firmware It then reads the voltage levels Turns on boost converted if voltage is to low Indicates whether the battery needs to be changed by blinking the LED

14 Firmware Real-Time Clock and Calendar Uses a high precision external oscillator Used for timestamping brushing events

15 Firmware It then checks to see if the toothbrush is connected a smartphone If connected the phone begins sending commands to the toothbrush It also sends the stored values for brushing events

16 Firmware The program then enters into Deep Sleep mode Deep Sleep turns off all module expect the RTCC Only uses 25nA which allows the battery to last longer

17 Capacitive Sensor Designed to be water resistant Water causes sensed voltage to increase User’s touch causes voltage to decrease

18 Capacitive Sensor Developed Cap Sensor for best coupling Size of 0.15 by 0.5 inches One digital output drives cap One analog input senses cap

19 Capacitive Sensing

20 Capacitive Sensing Sense line with user’s touch Sense line without user’s touch

21 Schematic EagleCAD was used to make schematic MCP1640 – boost converter PIC24F – 28 pin SSOP kHz crystal oscillator 3.5mm TRRS audio jack All resistors and capacitors – 0805 SMT size

22 Power Supply Boost voltage from 1.5V to 3.3V Controller switches boost converter on/off

23 Power Supply 3 connections to controller LED to indicated low battery Monitor Vout of boost converter Switch on/off using transistor

24 Printed Circuit Board All components located on top side of board Size limit of by 3 in. Made on campus by Doug Jackson Use of only 2 layers

25 PCB Improvement Moved the AUX input to the rear Moved the LED to the rear Moved components into a more compact area

26 Communication Data stored on brush needs to be sent to the smartphone Connect to Android + IPhone using the audio input

27 Steps in Communication 1)Smartphone requests stored data 2)Microprocessor modulates digital bits into audio frequencies (Frequency-Shift Keying) 3) Filter out high-frequency components of the signal 4)Smartphone receives the audio signal 5)Audio signal is converted back to a string of digital bits

28 Steps in Communication Digital 1 Digital Hz Audio Frequency 1200 Hz Audio Frequency Frequency-Shift Keying (FSK) Character to Binary: “8”  “ ”

29 FSK Test Results Successfully demodulated an audio command being sent to our toothbrush Successfully create an FSK modulated response

30 Commands and Responses Command:Response: Attention“ATT”“???” Get Date/Time“TME”MMDDYYhhmmss Number of Events“NUM”00-50 Firmware Version“SFT”“V1.0” Set Date/Time“SET”“NEW” Get Data“GET”Stored data Serial Number“SER”SN Delete Data“CLR”“DUN”

31 Design Constraints Size of PCB 0.625” x 3” Printed Circuit Board Low parts count Maximum functional integration on PIC24F Low power consumption One AAA Battery powers for three months

32 Conclusions Capacitive sensor is a great way of detecting the use of the Beam Brush FSK modulation is fully possible in software this PIC microcontroller Further research and modifications are necessary, but our design can eventually be released as a commercial product

33 Future Recommendations Study Power usage to estimate battery life Create learning algorithms for the microcontroller Test the electronics in an actual toothbrush unit for long-term use

34

35 Questions?