Project

# Title Team Members TA Documents Sponsor
16 Cost-Effective Signal Processing Solution for Bat-Call Detection and Hearing
 Liwei Koh
Michael Mcnally
Theo Xiong
 Tim Jiang Dr. Joy O'Keefe
# Cost-Effective Signal Processing Solution for Bat-Call Detection and Hearing

Team Members:

- Theo Xiong (tyxiong2)
- Michael McNally (mm153)
- Liwei Koh (liweitk2)

Sponsored by Dr. Joy O'Keefe and the Human-Wildlife Interactions Lab

# Problem

Reliable heterodyne bat-call detectors are difficult to obtain for under $150 in the United States. Affordable options such as the Magenta Electronics Bat4 (approximately £80) generally require international purchasing and shipping, while comparable devices available in the US, such as the Elekon BATSCANNER (approximately $395), are significantly more expensive. This limits researchers, students, and bat enthusiasts who want an affordable and accessible way to detect and listen to ultrasonic bat calls.

# Solution

Build a portable heterodyne bat detector with a 3D-printed housing that is able to detect ultrasonic bat calls and convert them into frequencies that can be heard by the user. The device will aim to provide similar core functionality to the Magenta Bat4, minus the flashlight, while also using signal processing to recommend a frequency range for the user to tune to.

# Solution Components

## Processing Subsystem

* Processes the microphone signal and performs an FFT to determine the most prominent frequency range being detected.
* Sends the detected frequency range to the display subsystem to recommend where the user should tune the detector.

## Microphone Subsystem

* Uses a directional ultrasonic microphone to pick up bat calls.
* Feeds the captured signal into both the processing and heterodyne subsystems.

## Heterodyne Subsystem

* Passes the microphone signal through filtering and amplification.
* Mixes the signal with a tunable local oscillator signal.
* Shifts the ultrasonic bat call into the human-audible frequency range.
* Filters and amplifies the resulting signal before sending it to the audio output.

## Power Subsystem

* Uses a 4×AA battery pack as the main power source for the device. A voltage regulator is used to provide a stable supply voltage to the microphone, processing, heterodyne, display, and audio subsystems. Basic filtering and an on/off switch are included to help provide clean and controllable power throughout the system.

## Display Subsystem

* Uses an Inland 1602 I2C LCD display module.
* Displays the recommended frequency range determined by the processing subsystem.
* Helps the user determine where to tune the detector.
* Also displays potential species detected

## Buttons/Dials

* Frequency Tuning Potentiometer: Allows the user to tune the detector through different frequency ranges, with approximately ±5 kHz of fine adjustment around the selected frequency.
* Calibration Button: Allows the user to calibrate the detector and initiate frequency analysis.
* Volume Dial: Controls the volume of the audible output.

# Criterion For Success

* The device should reliably detect the ultrasonic output produced by a bat-call simulator and convert it into an audible signal.
* The device should be practical to construct using readily available and accessible components.
* The device should provide adjustable tuning capabilities, allowing the user to cycle through different frequency ranges to improve detection performance.
* The device should be able to analyze the microphone signal and recommend a frequency range for the user to tune to.

## Stretch Goal

* Collect and analyze enough bat-call data to provide an estimate of the species of bat being detected based on characteristics such as its dominant frequency range.

Modularized Electronic Locker

Jack Davis, Joshua Nolan, Jake Pu

Modularized Electronic Locker

Featured Project

Group Member: Jianhao (Jake) Pu [jpu3], Joshua Nolan [jtnolan2], John (Jack) Davis [johnhd4]

Problem:

Students living off campus without a packaging station are affected by stolen packages all the time. As a result of privacy concerns and inconsistent deployment, public cameras in Champaign and around the world cannot always be relied upon. Therefore, it can be very difficult for victims to gather evidence for a police report. Most of the time, the value of stolen items is small and they are usually compensated by the sellers (Amazon and Apple are very understanding). However, not all deliveries are insured and many people are suffering from stolen food deliveries during the COVID-19 crisis. We need a low-cost solution that can protect deliveries from all vendors.

Solution Overview:

Our solution is similar to Amazon Hub Apartment Locker and Luxer One. Like these services, our product will securely enclose the package until the owners claim the contents inside. The owner of the contents can claim it using a phone number or a unique user identification code generated and managed by a cloud service.

The first difference we want to make from these competitors is cost. According to an article, the cost of a single locker is from $6000 - $20000. We want to minimize such costs so that we can replace the traditional mailbox. We talked to a Chinese manufacturer and got a hardware quote of $3000. We can squeeze this cost if we just design our own control module on ESP32 microcontrollers.

The second difference we want to make is modularity. We will have a sensor module, a control module, a power module and any number of storage units for hardware. We want to make standardized storage units that can be stacked into any configuration, and these storage units can be connected to a control module through a communication bus. The control module houses the hardware to open or close all of the individual lockers. A household can purchase a single locker and a control module just for one family while apartment buildings can stack them into the lockers we see at Amazon Hub. I think the hardware connection will be a challenge but it will be very effective at lowering the cost once we can massively manufacture these unit lockers.

Solution Components:

Storage Unit

Basic units that provide a locker feature. Each storage unit will have a cheap microcontroller to work as a slave on the communication bus and control its electronic lock (12V 36W). It has four connectors on top, bottom, left, and right sides for stackable configuration.

Control Unit

Should have the same dimension as one of the storage units so that it could be stacked with them. Houses ESP32 microcontroller to run control logics on all storage units and uses the built-in WiFi to upload data to a cloud server. If sensor units are detected, it should activate more security features accordingly.

Power Unit

Power from the wall or from a backup battery power supply and the associated controls to deliver power to the system. Able to sustain high current in a short time (36W for each electronic lock). It should also have protection against overvoltage and overcurrent.

Sensor Modules

Sensors such as cameras, motion sensors, and gyroscopes will parlay any scandalous activities to the control unit and will be able to capture a photo to report to authorities. Sensors will also have modularity for increased security capabilities.

Cloud Support

Runs a database that keeps user identification information and the security images. Pushes notification to end-users.

Criterion for Success:

Deliverers (Fedex, Amazon, Uber Eats, etc.) are able to open the locker using a touchscreen and a use- provided code to place their package inside. Once the package is inside of the locker, a message will be sent to the locker owner that their delivery has arrived. Locker owners are able to open the locker using a touchscreen interface. Owners are also able to change the passcode at any time for security reasons. The locker must be difficult to break into and offer theft protection after multiple incorrect password attempts.

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