The design will consist of three parts, each powered by an individual STM32 microcontroller: The wearable accessory, the wireless receiver, and the wired hub.
This is an STM32 device which the user will wear on their own body, either by putting the device in their chest pocket or by attaching it to an arm strap. The wearable accessory will detect panic attacks and send a signal to the wireless receiver to notify uWaterloo staff of the panic attack. Additionally, it will perform various functions in order to help the user calm down from their panic attack.
| Component | Purpose | Placement |
|---|---|---|
| Nucleo Case | Contain the STM32 and its peripherals, serving as a container/shell for the wearable accessory | The STM32 microcontroller will be located inside the case |
| Arm Strap | Allows the user to wear the device on their arm | The arm strap can be placed on the user’s arm |
| MB102 Breadboard Power Supply | Supply the STM32 and certain peripheral components with power received from the 9V Battery | The Power Supply will be located inside the case and connected to the 9V Battery to Barrel Jack Converter |
| 9V Battery to Barrel Jack Converter | Allow for the energy stored on the 9V Battery to be accessed by the Power Supply | The converter will be located inside the case and connected to the Power Supply and 9V Battery |
| 9V Battery | Supply the wearable accessory with power | The 9V Battery will be located inside the case, and connected to the 9V Battery to Barrel Jack Converter |
| Microphone Omni Directional | Monitor the breathing rate of the user to detect panic attacks | The microphone will be attached to the exterior of the Nucleo Case |
| AD8232 Heart Rate Monitor | Monitor the heart rate of the user to detect panic attacks | The heart rate sensor consists of three electrodes, which will be attached according to the User Manual |
| Output Wire for Skin Conductivity | Deliver a current that will pass through the user’s arm | The output wire will lead towards the user’s arm, on the opposite side of the input wire |
| Input Wire for Skin Conductivity | Receive the current produced by the Output Wire for the microcontroller to measure | The input wire will lead towards the user’s arm, on the opposite side of the output wire |
| Big RGB LED | Emit blue light to calm down the user during a panic attack | The LEDs will be attached to the exterior of the Nucleo Case |
| LCD Screen | Emit blue light and display positive and helpful text to calm down the user during a panic attack | The LCD will be attached to the exterior of the Nucleo Case |
| I2S Audio Breakout | Converts digital PWM signals to analog audio signals for the speaker | The breakout will be located inside the Nucleo Case |
| Speaker | Play relaxing sounds to calm down the user during a panic attack | The speaker will be attached to the exterior of the Nucleo Case |
| HW-203 SD Card Reader | Read the audio file from the SD card | The SD reader will be located in the Nucleo Case with the microcontroller |
| SD Card | Stores the audio file that will be played to calm down the user during a panic attack | The SD Card will be located in the SD Card Reader |
| IR Emitting LED | Emit a 52kHz IR signal to alert the wireless receiver that the user is experiencing a panic attack | The IR Emitting LED will be attached to the exterior of the Nucleo Case |
This is an STM32 device which will mounted to the walls of public uWaterloo buildings to detect for the panic attack distress signal emitted by the wearable accessory. If a distress signal is detected, the receiver will transmit an I2C signal to the wired hub over a wired connection.
| Component | Purpose | Placement |
|---|---|---|
| Infrared Receiver | Receive infrared light from the wearable accessory to detect that a user is experiencing a panic attack | The infrared receiver will be placed on the wall with the microcontroller |
| 2 Wires to Wired Hub | Communicate to the wired hub that a panic attack is occurring at its location | The wires will lead towards the wired hub |
This is the terminal used to inform uWaterloo staff of a panic attack that occurs within the range covered by the wireless receivers. An STM32 alerts uWaterloo staff of a panic attack, lighting up an LED when a panic attack is detected and specifying its location at LED. Since the wired hub communicates with its wireless receivers using the I2C protocol, the hub knows the location of the panic attack based on the I2C address sent by the wireless receiver
| Component | Purpose | Placement |
|---|---|---|
| LCD Screen | To display the signal location during a detected panic attack, to alert the uWaterloo staff | The LCD Screen will be placed beside the microcontroller |
| 2 Wires to Wireless Receiver | Detect signals from the wireless receiver to be alerted whenever a panic attack is detected | The wires will lead towards any wireless receivers |
| 12S Amp Speaker | Piezo Speaker |
|---|---|
| Larger in size | Smaller in size |
| Can play large range of sounds | Can only create buzzing |
| Needs 12S Audio Breakout module | Can connect directly to the microcontroller |
| More expensive | Less expensive |
Despite several aspects of the piezo speaker that make it preferable to the 12S Amp Speaker, we choose to use the 12S Amp Speaker in order to match with our requirement of playing calming audio. The piezo speaker can only create buzzing, which does not have any calming properties and will not fulfill our requirement.
I2C Wired Protocol: requires two wires between the wireless receiver and the wired hub, and allows for multiple wireless receivers each with their own distinct address. Using I2C allows for the wired hub to maintain a directory of all wireless receivers and their locations in uWaterloo. The STM32 has built-in software for handling I2C wired connections.
High-Low Wired Signals: requires one wire, and is a simple approach to alerting the wired hub that a panic attack has been detected by the wireless receiver