Project

# Title Team Members TA Documents Sponsor
29 Renter-Friendly Fob-Activated Door Lock
 Adam Quiballo
Antonio Laverd
Max Zhang
 Nikhil Arora design_document1.pdf
design_document2.pdf
final_paper1.pdf
presentation1.pdf
proposal2.pdf
proposal1.pdf
video
# Team Members:

* adamq3
* alaverd2
* mjzhang3

# Problem

How many times have you been carrying ten bags of groceries and arrived at a locked front door, or been pressed for time and had to fumble through a set of keys? These frustrating and time-consuming issues could be solved by a commercial “smart lock” system, however this solution is not renter-friendly because it requires replacement of a deadbolt.

# Solution

Now imagine the same scenario at your rented apartment, except you arrive at a front door which automatically unlocks with a powered wireless transmitter, instead of fumbling with a traditional key.

Our solution is an induction-powered RFID system that uses a battery-powered fob to automatically open the door lock when held up to the lock, instead of a traditional key. When the correct fob transmitter frequency is detected, a motor would immediately spin to open the deadbolt. There would also be a button activating a ”locking” capacitor to re-engage the deadbolt. This would build off of Project 40 from Spring 2023 by incorporating a separate inductive charging coil from the transmitter (a device acting like a phone) on top of the identification coil that was previously done. In this solution the RFID reader alone wouldn’t unlock the door, because in order to power the servo motor remotely it needs more power then the RFID tag could receive and transfer. This will happen transiently, either simultaneously sending the data and the power at the same time or by charging the circuit first and then sending data.


# Solution Components
## Subsystem 1: Wireless Charging

The induced electromagnetic field from the RFID reader alone is not powerful enough to power a motor to open a deadbolt even with amplification from a battery pack. Our solution is to utilize a second coil in the fob that can inductively charge the receiver circuit to power the motor and LED. The wireless charging system will include a small backup battery which is only engaged in the case that the induced current in the door's circuit is prematurely cut off before the deadbolt is done reaching its ending position. We are using separate coils for the RFID and induction charging systems to better modularize our design. An IC that was documented by digikey that could work for this subsystem is this [Wireless Power Receiver](https://www.digikey.com/en/products/detail/stmicroelectronics/STWLC33JR/497-17649-1-ND/7702488) and [Digital Power Controller](https://www.digikey.com/en/products/detail/stmicroelectronics/STWBC-EPTR/497-17636-1-ND/7702478) that would work with this system. This is a possible [coil ](https://www.digikey.com/en/products/detail/wurth-electronics-inc/760308104113/732-5717-ND/4988096) that these ICs can communicate with.


## Subsystem 2: RFID (radio frequency ID)

Using a separate coil to that of the Wireless Charging subsystem, we will transfer data using the fob as an RFID transmitter to send a simple signal that must match the frequency of the door lock so that the fob and lock can identify each other. RFID technology is available on many compatible chips and will function with our design. This subsystem will exist both in our fob and will be on the door unit which connects to and powers the motor subsystem, making for a total of two PCB boards.

## Subsystem 3: Servo Motors

A [low voltage servo motor](https://www.towerpro.com.tw/product/mg996r/) will be in the door module that applies enough torque to push a standard deadbolt. The hyperlinked motor has a maximum current draw of 1.4 amps, and the maximum current that can be supplied by the coil we included in subsystem 1 is 7 amps. This guarantees that the power supplied by our wireless charging subsystem will be powerful enough to instantaneously push a deadbolt with the motor. Logic on the door's PCB board will detect if the motor reaches its stall current and disengage it to prevent it from burning out if, for example, the deadbolt’s path is obstructed.

## Subsystem 4: LED indicators

In both the fob and door, we will use an LED controlled by a microcontroller which determines when the battery is low. In addition, an LED in the in-door RFID subsystem will turn green to indicate successful user identification.

# Criterion For Success

It is important to mention several ideas in this RFA overlap with Project 40 that was previously done in Spring 2023. We will take the previous advice that we will not have any requirements stating it has to be mounted on the door or the original key needs to still function. Our goals and ideas will be very similar to the previous project but we seek to improve upon the design in order to better meet the goal that our project is renter friendly.

Our criterion for success are:

* Wireless charging of the device that turns the deadbolt within 2 seconds
* Successful RFID reading of data indicated by green flashing LED on door unit when fob frequency is successfully identified
* Motors engage and disengage standard deadbolt
* Deadbolt stops and returns to unlock position if path is obstructed (successful stall current detection)
* LEDs light up to indicate low battery voltage on the fob module and door module

Prosthetic Control Board

Caleb Albers, Daniel Lee

Prosthetic Control Board

Featured Project

Psyonic is a local start-up that has been working on a prosthetic arm with an impressive set of features as well as being affordable. The current iteration of the main hand board is functional, but has limitations in computational power as well as scalability. In lieu of this, Psyonic wishes to switch to a production-ready chip that is an improvement on the current micro controller by utilizing a more modern architecture. During this change a few new features would be added that would improve safety, allow for easier debugging, and fix some issues present in the current implementation. The board is also slated to communicate with several other boards found in the hand. Additionally we are looking at the possibility of improving the longevity of the product with methods such as conformal coating and potting.

Core Functionality:

Replace microcontroller, change connectors, and code software to send control signals to the motor drivers

Tier 1 functions:

Add additional communication interfaces (I2C), and add temperature sensor.

Tier 2 functions:

Setup framework for communication between other boards, and improve board longevity.

Overview of proposed changes by affected area:

Microcontroller/Architecture Change:

Teensy -> Production-ready chip (most likely ARM based, i.e. STM32 family of processors)

Board:

support new microcontroller, adding additional communication interfaces (I2C), change to more robust connector. (will need to design pcb for both main control as well as finger sensors)

Sensor:

Addition of a temperature sensor to provide temperature feedback to the microcontroller.

Software:

change from Arduino IDE to new toolchain. (ARM has various base libraries such as mbed and can be configured for use with eclipse to act as IDE) Lay out framework to allow communication from other boards found in other parts of the arm.