Project

# Title Team Members TA Documents Sponsor
84 Mobile stray cat rescue station
 Frank Chen
Ming Yi
Yilin Tan
 Rui Gong design_document1.pdf
final_paper1.pdf
proposal1.pdf
video
#Group members
- Yilin Tan(ytan47)
- Ming Yi(myi22)
- Frank Chen(sihan6)

# Problem:
For now, because of the kind people from all walks of life and the existence of many adoption agencies, it is difficult for us to see stray animals on the street without a fixed place to live, but this is not absolute! Because in my community, I always see a lot of stray cats, regardless of age and species. When I meet them, they are not necessarily alive. The cold and food shortage will threaten their lives. And every time I want to help them, I can't just happen to be able to provide them with food. Even if I can give them food, the stray cat population and its offspring will continue to wander. So my idea is how to help them live better. I plan to build a portable stray cat rescue station that can be placed in areas where stray cats are present to provide them with warmth and food.

# Solution:
My solution is to design a wireless constant temperature device that can detect the temperature in the cat's nest at all times to determine whether the heating device is turned on and off. Then equip it with feeding equipment, and detect whether there is enough food in the cat's food bin. Through wireless data transmission, maintenance personnel can decide whether to add food to the equipment according to the data.

This device includes the following modules:
Power supply module: as the power source of the entire device and other subsystems
Heating module: to control the device temperature
Main control module: transmit real-time data of the device
Casing and heating layer: enhance the warmth of the device at the physical level

#Solution components:

## Subsystem 1: Power supply module
Overview: This subsystem uses solar panels and lithium batteries to realize the device power supply system. While avoiding the trouble of replacing batteries, it can also realize the convenience of this device and can be installed outdoors. It is also conducive to the operation of subsystem 2 (heating module) at night.

Design:
Power generation method: solar panels can generate solar energy outdoors
Power storage method: use lithium batteries of suitable capacity to store electricity

## Subsystem 2: Heating module

Overview: This subsystem automatically controls the temperature in the device through heating equipment and temperature and humidity sensors

Design:
Heating method: heating by laying heating wires in the device
Temperature control method: use temperature and humidity sensors to detect whether the temperature in the device is lower than the set value and turn on the heating device, and the temperature can be monitored in real time through subsystem 3 (main control module)

## Subsystem 3: Main control module

Overview: Detect data in the device and transmit data wirelessly to the receiving station

Design:
Transmission method: Use LoRa devices for transmission to ensure that data is obtained when there is no network in the wild.
Reserve detection: Use pressure or infrared sensors to detect food residue
Power monitoring: Real-time recording of battery remaining power
Activity detection (optional): Infrared sensor detects cat entry and exit (optional: camera monitoring, but it is not suitable for no network and the price is higher.)

## Subsystem 4: Shell and heating layer

Overview: Use physical methods to assist and strengthen the role of subsystem 2 (temperature control module), and reduce power consumption.

Design:
Shell: Waterproof plastic board, aluminum plate or 3D printing material, and a metal frame about 10 cm above the ground to prevent rainy weather
Inner layer: Warm and fireproof foam board or other insulation material

# Criterion For Success:
This design would be considered successful if
The heater will automatically turn on and off when the temperature is within the set value range
When there is not enough food in the feeding bowl, it will automatically dispense food
Ability to obtain various real-time data on the LoRa master station

Phone Audio FM Transmitter

Madigan Carroll, Dan Piper, James Wozniak

Phone Audio FM Transmitter

Featured Project

# Phone Audio FM Transmitter

Team Members:

James Wozniak (jamesaw)

Madigan Carroll (mac18)

Dan Piper (depiper2)

# Problem

In cars with older stereo systems, there are no easy ways to play music from your phone as the car lacks Bluetooth or other audio connections. There exist small FM transmitters that circumvent this problem by broadcasting the phone audio on some given FM wavelength. The main issue with these is that they must be manually tuned to find an open wavelength, a process not easily or safely done while driving.

# Solution

Our solution is to build upon these preexisting devices, but add the functionality of automatically switching the transmitter’s frequency, creating a safer and more enjoyable experience. For this to work, several components are needed: a Bluetooth connection to send audio signals from the phone to the device, an FM receiver and processing unit to find the best wavelength to transmit on, and an FM transmitter to send the audio signals to be received by the car stereo.

# Solution Components

## Subsystem 1 - Bluetooth Interface

This system connects the user’s phone, or other bluetooth device to our project. It should be a standalone module that handles all the bluetooth functions, and outputs an audio signal that will be modulated and transmitted by the FM Transmitter. Note: this subsystem may be included in the microcontroller.

## Subsystem 2 - FM Transmitter

This module will transmit the audio signal output by our bluetooth module. It will modulate the signal to FM frequency chosen by the control system. Therefore, the transmitting frequency must be able to be tuned electronically.

## Subsystem 3 - FM Receiver

This module will receive an FM signal. It must be able to be adjusted electronically (not with a mechanical potentiometer) with a signal from the control system. It does not need to fully demodulate the signal, as we only need to measure the power in the signal. Note: if may choose to have a single transceiver, in which case the receiver subsystem and the transmitter subsystem will be combined into a single subsystem.

## Subsystem 4 - Control System

The control system will consist of a microcontroller and surrounding circuitry, capable of reading the power output of the FM receiver, and outputting a signal to adjust the receiving frequency, in order to scan the FM band. We will write and upload a program to determine the most suitable frequency. It will then output a signal to the FM transmitter to adjust the transmitting frequency to the band determined above. We are planning on using the ESP32-S3-WROOM-1 microcontroller given its built-in Bluetooth module and low power usage.

## Subsystem 5 - Power

Our device is designed to be used in a car, so It must be able to be powered by a standard automobile auxiliary power outlet which provides 12-13V DC and usually at least 100W. This should be more than sufficient. We plan to purchase a connector that can be plugged into this port, with leads that we can wire to our circuit.

# Criterion for Success

The device can pair with a phone via bluetooth and receive an audio signal from a phone.

The Device transmits an FM signal capable of being detected by a standard fm radio

The Device can receive FM signals and scan the FM bands.

The digital algorithm is able to compare the strength of different channels and determine the optimal channel.

The device is able to automatically switch the transmitting channel to the predetermined best channel when the user pushes a button.