Project

# Title Team Members TA Documents Sponsor
18 Self-Charging Automatic Bike Lock
 Jake Li
Paul Jeong
Rithik Morusupalli
 Jason Zhang design_document2.pdf
final_paper1.pdf
presentation1.pptx
proposal2.pdf
video
**Team Members**
- Paul Jeong (paulj3@illinois.edu)
- Rithik Morusupalli (rmorus2@illinois.edu)
- Jake Li (jli301@illinois.edu)

**Problem**

Stolen bikes are a big problem in Champaign, necessitating bike locks and alarms. However, basic bike locks are mechanical, and once broken, the bike can be easily stolen. Also, most bike alarms require a remote to enable and disable it.

**Solution**

Our solution to this issue is an automatic bike lock with an alarm system. This device will be attached to a bike with a clamp and will contain a physical locking mechanism and an alarm device. The physical lock will consist of a linear actuator that inserts itself through the wheel spokes (therefore preventing the wheel to spin) and touch sensors whose input will change the linear actuator’s state, while the alarm device will have a small speaker and a flashing light. The device’s microprocessor will also have bluetooth functionality. To lock and unlock the device, it has to be paired to the user’s phone with bluetooth and the user needs to correctly input the correct touch sequence into the touch sensor input. The device also contains a self charging subsystem, which will charge the device when the vibration sensor is triggered (bike is moving).

**Solution Components**
- PCB and Microcontroller: STM32WB55CCU7
- Power Subsystem: Lithium ion Battery (3.7V 2000mAh), Buck Boost regulator (LTC3115), Piezo Vibration Sensor (SEN-09196 ROHS)
- Charging Subsystem: 24V 30W 3500RPM DC Motor
- Bluetooth Subsystem: contained on the STM32WB55CCU7
- Touchpad Subsystem: TTP223B Capacitive Touch Sensor
- Physical Locking Subsystem: Mini Linear Actuator B07ZJ46947
- Alarm Subsystem: Piezo Vibration Sensor (SEN-09196 ROHS), Mini Speaker - PC Mount 12mm 2.048kHz (COM-07950 ROHS), ADDRESS LED RING SERIAL RGB (COM-14967)

**PCB and Microcontroller**

The STM32WB55CCU7 will require a bluetooth connection from a mobile device to access the touchpad subsystem. Then, a correct code from the touchpad subsystem is required to unlock the physical subsystem as well as disable the alarm subsystem. The microcontroller will make sure the bike is in motion with the vibration sensor in order to enable the charging subsystem. The charging subsystem will disable when there is no vibration detected based on a certain threshold to allow variables like wind and minor bumping. Then a correct code from the touchpad will enable the physical locking subsystem and enable the alarm subsystem.
This subsystem controls the overall interactions among all subsystems.

**Power Subsystem - heavily collaborates with the Charging Subsystem**

Our power subsystem will consist of a set of rechargeable Lithium ion Batteries (3.7V 2000mAh) in parallel that allows us to power the PCB and microcontroller. To ensure that we meet the demands of all of our subsystems while also ensuring even power distribution we also plan on including a Buck Boost regulator (LTC3115) to ensure no power spikes or drops affect the overall apparatus. Depending on the readings of the vibration sensor, the power system will either be in a state of charging through the charging subsystem, or in a state of discharging. If a certain amount of vibration is detected (ie you are riding the bike around) we want to shut off the discharge of the battery pack and allow it to recharge. If the amount of vibration is lower than a certain threshold (ie the bike is stationary) we want to begin discharging the battery pack and therefore power the entire system.

**Charging Subsystem - heavily collaborates with the Power Subsystem**

The DC motor will be attached to the rear axle and directly wired up to the main power subsystem through the buck boost regulator. As the rear wheel spins, the DC motor will spin along with it, therefore creating the kinetic energy that we will use to charge the rechargeable battery pack. The charging subsystem will only be active when there is bluetooth connection, meaning the user is near or riding the bike, and the vibration sensor detects enough movement.

**Bluetooth Subsystem**

The bluetooth subsystems act as the first level of security in our bike lock. It is controlled via the STM32WB55CCU7 microcontroller that has onboard Bluetooth 5.4. Once paired with the user’s mobile device, it will automatically connect when the mobile device is in range with bluetooth on. Thus allowing access to the second level of security in our overall locking subsystem

**Touchpad Subsystem**

The second security level of our locking system. Once the Bluetooth signal is recognized and within our chosen activation range, the touchpad subsystem becomes activated. The user must then input the correct touch sequence on the array of TTP223B Capacitive Touch Sensors. If the correct sequence is met, then the physical locking subsystem will disengage or engage according to the previous state of the physical locking subsystem. We need this second level as more of a user safety device than an anti-theft mechanism. This will address the edge cases in which the Bluetooth device is within detectable range, but the owner does not wish for the physical lock to change states or when the user is riding the bike and loses their remote and it falls out of range.

**Physical Locking Subsystem**

This subsystem is the primary physical component of our system. Consisting of a linear actuator (Mini Linear Actuator B07ZJ46947) that extends through the wheel spokes when the lock is activated, the solenoid prevents the movement of the wheel the locking apparatus is clamped to. We plan for this subsystem to be attachable to either the front or rear wheel through the use of a clamping mechanism that connects to the different cylinders that make up a bicycle.

**Alarm Subsystem**

The inbuilt alarm subsystem to the overall system enclosure. This subsystem consists of both a LED that acts as a flashing light and a speaker that should act to draw attention to the fact that someone is attempting to steal a bike. This subsystem should be activated if the overall system is being tampered with. Including situations such as attempts to access the touch subsystem without the paired Bluetooth device nearby, repeated mistakes in the touch combination once the touch subsystem is activated, and the vibration sensor detecting large movements like attempting to force the solenoid closed.

**Criterion For Success**

- Portable locking system that has the capability to clamp onto different bikes and also not clutter the bicycle.
- Self-charging capability, utilizing the spin of the rear wheel to recharge the battery that powers the system.
- Two levels of security for the looking system. First, an onboard bluetooth device that allows access to the second level of security if the paired bluetooth device is within range of ~5ft (due to change)
- The second level of security is a keypad that acts as a touch combination lock that activates the physical locking mechanism.
- Alarm system (sound and flashing LED) that gets activated when the lock is tampered with without the paired bluetooth device present and/or the incorrect pin/touch combination.

Electronic Replacement for COVID-19 Building Monitors @ UIUC

Patrick McBrayer, Zewen Rao, Yijie Zhang

Featured Project

Team Members: Patrick McBrayer, Yijie Zhang, Zewen Rao

Problem Statement:

Students who volunteer to monitor buildings at UIUC are at increased risk of contracting COVID-19 itself, and passing it on to others before they are aware of the infection. Due to this, I propose a project that would create a technological solution to this issue using physical 2-factor authentication through the “airlock” style doorways we have at ECEB and across campus.

Solution Overview:

As we do not have access to the backend of the Safer Illinois application, or the ability to use campus buildings as a workspace for our project, we will be designing a proof of concept 2FA system for UIUC building access. Our solution would be composed of two main subsystems, one that allows initial entry into the “airlock” portion of the building using a scannable QR code, and the other that detects the number of people that entered the space, to determine whether or not the user will be granted access to the interior of the building.

Solution Components:

Subsystem #1: Initial Detection of Building Access

- QR/barcode scanner capable of reading the code presented by the user, that tells the system whether that person has been granted or denied building access. (An example of this type of sensor: (https://www.amazon.com/Barcode-Reading-Scanner-Electronic-Connector/dp/B082B8SVB2/ref=sr_1_11?dchild=1&keywords=gm65+scanner&qid=1595651995&sr=8-11)

- QR code generator using C++/Python to support the QR code scanner.

- Microcontroller to receive the information from the QR code reader and decode the information, then decide whether to unlock the door, or keep it shut. (The microcontroller would also need an internal timer, as we plan on encoding a lifespan into the QR code, therefore making them unusable after 4 days).

- LED Light to indicate to the user whether or not access was granted.

- Electronic locking mechanism to open both sets of doors.

Subsystem #2: Airlock Authentication of a Single User

- 2 aligned sensors ( one tx and other is rx) on the bottom of the door that counts the number of people crossing a certain line. (possibly considering two sets of these, so the person could not jump over, or move under the sensors. Most likely having the second set around the middle of the door frame.

- Microcontroller to decode the information provided by the door sensors, and then determine the number of people who have entered the space. Based on this information we can either grant or deny access to the interior building.

- LED Light to indicate to the user if they have been granted access.

- Possibly a speaker at this stage as well, to tell the user the reason they have not been granted access, and letting them know the

incident has been reported if they attempted to let someone into the building.

Criterion of Success:

- Our system generates valid QR codes that can be read by our scanner, and the data encoded such as lifespan of the code and building access is transmitted to the microcontroller.

- Our 2FA detection of multiple entries into the space works across a wide range of users. This includes users bound to wheelchairs, and a wide range of heights and body sizes.