Project

# Title Team Members TA Documents Sponsor
33 HelpMeRecall
 Michael Jiang
Sravya Davuluri
William Li
 Hossein Ataee design_document2.pdf
final_paper2.pdf
proposal3.pdf
video
# HelpMeRecall

Team Members:
- Sravya Davuluri (sravyad2)
- William Li (wli202)
- Michael Jiang (mbjiang2)

# Problem

Many individuals have difficulty remembering recent activities and completing routine tasks like eating or taking medication.

# Solution

A standalone assistive device that supports activity recall using sensor-gated voice interaction. It allows users to verbally log activities they have completed, and later query if a specific activity has been performed. It uses an onboard microphone and on-device audio processing on a microcontroller to perform keyword detection.

This device is always on and will be verifiable with an LED, but the voice input is only accepted if the device is worn (capacitive touch sensor) and specific words from a limited vocabulary is said to avoid accidental logging. To address the possibility of reduced correct detection of supported keywords, we will have various keywords targeted for an activity. So in the case of taking medicine, it might be medicine, medication, pill, drug, and prescription. This also simplifies the problem and prevents confidence rate issues. To validate a completed action, the action is logged only if an accelerometer detects physical movement around the time in order to reduce false logging. If a voice log is accepted, haptic feedback is provided by the device. Activities are also timestamped and stored in local memory. If the device notes that a specific activity has been completed, it affirms it including the timestamp using an integrated speaker.

The logs reset at midnight automatically since the activities repeat on the daily. There is also an option of a hard reset button to clear logs. There will also be a button to delete the latest log in case of a logging mistake by the user.

# Solution Components

## Subsystem 1: Microcontroller Unit and Controls

Acts as the central unit for logic. Manages the sensor inputs, and executes a finite state machine. The FSM states are start, idle, listening, logging, and replying.

Components: ESP32-S3-WROOM-1

## Subsystem 2: Audio input processing unit

Captures the voice input from the user and performs keyword detection on a limited vocabulary, where each action can be mapped to multiple set keywords to improve detection.

Components: Digital MEMS microphone (INMP441), ESP32-S3-WROOM-1

## Subsystem 3: Sensor gating and activity validation

Uses a capacitive touch sensor and an accelerometer to detect motion, which ensures that voice input is only received and accepted if the device is worn and recent movement is detected by the accelerometer instead of continuous voice recognition. A "cooldown" period is enforced where the microphone will be disabled for 10 seconds if there's motion but no logging during the listening period multiple times in a row to help conserve some battery.

Components: Capacitive touch sensor (AT42QT1010), Accelerometer (MPU-6050)

## Subsystem 4: Feedback and Output

Uses a speaker for audio feedback as a response to the user’s query. This subsystem also provides haptic feedback as an indication of an accepted user voice log. To indicate if the device is on, the LED is green. If the device is listening, the LED is yellow. If the device is low on power, the LED will be red.

Components: Speaker (8 ohm speaker), amplifier (MAX98357A), coin vibration motor, transistor (2N3904), RGB LED

## Subsystem 5: Time logging and local storage

Stores the activity voice logs along with timestamps. Allows automatic reset at midnight to support daily repetitive tasks. Timekeeping is done using ESP32’s internal RTC.

Components: ESP32-S3-WROOM-1

## Subsystem 6: Power

Supplies power to the device.

Components: Battery (Li-Po battery)

# Criterion For Success
- Correctly detects supported keywords with an accuracy of at least 80% in a quiet environment
- Device will only log upon verifying physical activity and hearing a keyword from the user within a 5 second window
- Upon successful logging, the speaker will output audibly and haptic feedback can be felt by the user with a 2 second vibration
- While querying logs, speaker will output and LED will be solid
- Logs will be automatically cleared at midnight and can be manually reset with the reset button
- Latest log will be deleted upon pushing a separate button
- LED stays solid while device is powered
- False log rate < 1 per hour in normal conversation when worn.

Tesla Coil Guitar Amp

David Mengel, Griffin Rzonca

Featured Project

# Tesla Coil Guitar Amp

Team Members:

* Griffin Rzonca (grzonca2)

* David Mengel (dmengel3)

# Problem:

Musicians are known for their affinity for flashy and creative displays and playing styles, especially during their live performances. One of the best ways to foster this creativity and allow artists to express themselves is a new type of amp that is both visually stunning and sonically interesting.

# Solution:

We propose a guitar amp that uses a Tesla coil to create a unique tone and dazzling visuals to go along with it. The amp will take the input from an electric guitar and use this to change the frequency of a tesla coil's sparks onto a grounding rod, creating a tone that matches that of the guitar.

# Solution Components:

## Audio Input and Frequency Processing -

This will convert the output of the guitar into a square wave to be fed as a driver for the tesla coil. This can be done using a network of op-amps. We will also use an LED and phototransistor to separate the user from the rest of the circuit, so that they have no direct connection to any high voltage circuitry. In order to operate our tesla coil, we need to drive it at its resonant frequency. Initial calculations and research have this value somewhere around 100kHz. The ESP32 microcontroller can create up to 40MHz, so we will use this to drive our circuit. In order to output different notes, we will use pulses of the resonant frequency, with the pulses at the frequency of the desired note.

## Solid-state switching -

We will use semiconductor switching rather than the comparably popular air-gap switching, as this poses less of a safety issue and is more reliable and modifiable. We will use a microcontroller, an ESP 32, to control an IR2110 gate driver IC and two to four IGBTs held high or low in order to complete the circuit as the coil triggers, acting in place of the air gap switch. These can all be included on our PCB.

## Power Supply -

We will use a 120V AC input to power the tesla coil and most likely a neon sign transformer if needed to step up the voltage to power our coil.

## Tesla Coil -

Consists of a few wire loops on the primary side and a 100-turn coil of copper wire in order to step up voltage for spark generation. Will also require a toroidal loop of PVC wrapped in aluminum foil in order to properly shape the electric field for optimal arcing. These pieces can be modular for easy storage and transport.

## Grounding rod -

All sparks will be directed onto a grounded metal rod 3-5cm from the coil. The rest of the circuit will use a separate neutral to further protect against damage. If underground cable concerns exist, we can call an Ameren inspector when we test the coil to mark any buried cables to ensure our grounding rod is placed in a safe location.

## Safety -

Tesla coils have been built for senior design in the past, and as noted by TAs, there are several safety precautions needed for this project to work. We reviewed guidelines from dozens of recorded tesla coil builds and determined the following precautions:

* The tesla coil will never be turned on indoors, it will be tested outside with multiple group members present using an outdoor wall outlet, with cones to create a circle of safety to keep bystanders away.

* We will keep everyone at least 10ft away while the coil is active.

* The voltage can reach up to 100kV (albeit low current) so all sparks will be directed onto a grounding rod 3-5cm away, as a general rule of thumb is each 30kV can bridge a 1cm gap.

* The power supply (120-240V) components will be built and tested in the power electronics lab.

* The coil will have an emergency stop button and a fuse at the power supply.

* The cable from the guitar will use a phototransistor so that the user is not connected to a circuit with any power electronics.

# Criterion for Success:

To consider this project successful, we would like to see:

* No safety violations or injuries.

* A tesla coil that produces small visible and audible 3-5cm sparks to our ground rod.

* The coil can play several different notes and tones.

* The coil can take input from the guitar and will play the corresponding notes.

Project Videos