Project

# Title Team Members TA Documents Sponsor
4 Integrated Li-ion Battery Sensors
James Wyeth
Karl Mulnik
Evan Widloski design_document0.pdf
design_document0.docx
final_paper0.pdf
other0.zip
photo0.jpg
presentation0.pptx
proposal0.pdf
Illini Solar Car
ECE 445 RFA:
Members:
jamesw2
mulnik2

Web Board Link: https://courses.engr.illinois.edu/ece445/pace/view-topic.asp?id=27360
Block Diagram: https://imgur.com/a/K8ku9oV

Introduction and motive
This project is an improvement on current battery monitoring for an electric vehicle battery pack. The goal is to design modular sensing circuitry to send data to a central BMS. For each module, 6 temperatures and 2 voltages need to be measured. The system needs to be permanently attached to the batteries and use minimal wiring.

The batteries are currently held in place with PCBs, forming a module of 2 cells in series and many in parallel. The plan is to redesign these PCBs to integrate the system onto them. Each module shall have a µC and supporting circuitry to perform measurements and send them to the BMS. In order to reduce isolation issues we have had in the past, the system shall be powered by the module it is attached to, and the ground reference will be the negative of the cell. Also, communications shall be isolated and daisy-chained to keep isolation voltages low and reduce wiring.

Over the course of a race, packs cannot be modified and automatic balancing isn't guaranteed. As such, power consumption needs to be minimal and fairly consistent across all modules. This can be done by finding a low power µC and having it off most of the time.

Specification:
Voltage accuracy: 10 mV
Temperature accuracy: .1 C

Primary Goals:
Replace current sensors
Get a low power µC
Integrated on PCBs
Power off cell
Keep balance
Isolate comms
Daisy-chain self-addressing
Custom comms protocol

Habit-Forming Toothbrush Stand

John Kim, Quinn Palanca, Rahul Vasanth

Habit-Forming Toothbrush Stand

Featured Project

I spoke with a TA that approved this idea during office hours today, and they said I should submit it as a project proposal.

# Habit-Forming Toothbrush Stand

Team Members:

- Rahul Vasanth (rvasant2)

- Quinn Andrew Palanca (qpalanc2)

- John Jung-Yoon Kim (johnjk5)

# Problem

There are few habits as impactful as good dental hygiene. Brushing teeth in the morning and night can significantly improve health outcomes. Many struggle with forming and maintaining this habit. Parents might have a difficult time getting children to brush in the morning and before sleep while homeless shelter staff, rehab facility staff, and really, anyone looking to develop and track this habit may want a non-intrusive, privacy-preserving method to develop and maintain the practice of brushing their teeth in the morning. Keeping track of this information and but not storing it permanently through a mobile application is something that does not exist on the market. A small nudge is needed to keep kids, teenagers, and adults of all ages aware and mindful about their brushing habits. Additionally, many tend to zone out while brushing their teeth because they are half asleep and have no idea how long they are brushing.

# Solution

Our solution is catered toward electric toothbrushes. Unlike specific toothbrush brands that come with mobile applications, our solution applies to all electric toothbrushes, preserves privacy, and reduces screen time. We will implement a habit-forming toothbrush stand with a microcontroller, sensors, and a simple LED display that houses the electric toothbrush. A band of sensors will be wrapped around the base of the toothbrush. Lifting the toothbrush from the stand, turning it on, and starting to brush displays a timer that counts seconds up to ten minutes. This solves the problem of brushing too quickly or losing track of time and brushing for too long. Additionally, the display will provide a scorecard for brushing, with 14 values coming from (morning, night) x (6daysago, 5daysago, . . . , today) for a "record" of one week and 14 possible instances of brushing. This will augment the user's awareness of any new trends, and potentially help parents, their children, and other use cases outlined above. We specifically store just one week of data as the goal is habit formation and not permanent storage of potentially sensitive health information in the cloud.

# Solution Components

## Subsystem 1 - Sensor Band

The sensor band will contain a Bluetooth/Wireless Accelerometer and Gyroscope, or Accelerometer, IR sensor (to determine height lifted above sink), Bluetooth/Wireless connection to the microcontroller. This will allow us to determine if the electric toothbrush has been turned on. We will experiment with the overall angle, but knowing whether the toothbrush is parallel to the ground, or is lifted at a certain height above the sink will provide additional validation. These outputs need to be communicated wirelessly to the habit-forming toothbrush stand.

Possibilities: https://www.amazon.com/Accelerometer-Acceleration-Gyroscope-Electronic-Magnetometer/dp/B07GBRTB5K/ref=sr_1_12?keywords=wireless+accelerometer&qid=1643675559&sr=8-12 and individual sensors which we are exploring on Digikey and PCB Piezotronics as well.

## Subsystem 2 - Toothbrush Base/Stand and Display

The toothbrush stand will have a pressure sensor to determine when the toothbrush is lifted from the stand (alternatively, we may also add on an IR sensor), a microcontroller with Bluetooth capability, and a control unit to process sensor outputs as well as an LED display which will be set based on the current state. Additionally, the stand will need an internal clock to distinguish between morning and evening and mark states accordingly. The majority of sensors are powered by 3.3V - 5V. If we use a battery, we may include an additional button to power on the display (or just have it turn on when the pressure sensor / IR sensor output confirms the toothbrush has been lifted, or have the device plug into an outlet.

# Criterion For Success

1. When the user lifts the toothbrush from the stan and it begins to vibrate (signaling the toothbrush is on), the brushing timer begins and is displayed.

2. After at least two minutes have passed and the toothbrush is set back on the stand, the display correctly marks the current day and period (morning or evening).

3. Track record over current and previous days and the overall weekly record is accurately maintained. At the start of a new day, the record is shifted appropriately.

Project Videos