Hardware

Hardware Resources

The Srivastava Senior Design Lab has a wide variety of hardware available for use in projects, including microcontrollers, DSP boards, LINX RF transmitters and receivers, GPS units, webcams and more. These things can all be checked out from you TA for use on your project. See below for more details, and check out the links above.

Development Boards

Intel Galileo Development Boards

The lab has 25 Intel Galileo Development Boards available for checkout. The following links are useful resources for working with these boards:

Microcontrollers

PIC Microcontrollers

The lab has a number of PIC16F877A microcontrollers available for use in projects. It is understandable that wiring errors might happen, so each student is allowed to burn out a maximum of two PICs. They are programmed in a simplified C instruction set and are used to simplify design and perform IO with ease. Check the PIC Tutorial for more information.

BASIC Stamp Microcontrollers

The BASIC Stamp is a simple, tiny microcontroller with serial communications abilities, programmed in BASIC. This makes it ideal for simple applications where I/O speed is not critical, and the complexity of the HC12 is not needed.

DSPs

TI TMS320C54x DSPs

We have several C54x DSPs available for checkout (if demand is high, sharing a DSP with another group may be needed). Check out these resources for more information:

TI TMS320C6713 DSP

We have one TMS320C6713 (16 Mb) Floating Point DSP that was graciously donated by TI. The board is in the TA cabinet and is available for checkout.

LINX RF modules

We have a number of LINX transmitters and receivers available in the lab for RF projects, with a choice of the LC Series (315 or 418 MHz) or the HP series (902-928 MHz band).

GPS kits

We have 2-3 Garmin 12 XL GPS receivers. The Garmin units are equipped with a serial communication port and can be interfaced with microcontrollers or computers to provide information on position (lat, long, altitude, time) and velocity (differentiation of position). We also have one equivalent Motorola kit, and another kit by Ashtech (Eval and development kit, 990285). There are antennas on the roof of EL with wires into the lab so that data can be acquired while in the building (for testing purposes). The antennas can be accessed through connectors in the back left corner of the lab, by the far computer.

UV Sensor and Alert System - Skin Protection

Liz Boehning, Gavin Chan, Jimmy Huh

UV Sensor and Alert System - Skin Protection

Featured Project

Team Members:

- Elizabeth Boehning (elb5)

- Gavin Chan (gavintc2)

- Jimmy Huh (yeaho2)

# Problem

Too much sun exposure can lead to sunburn and an increased risk of skin cancer. Without active and mindful monitoring, it can be difficult to tell how much sun exposure one is getting and when one needs to seek protection from the sun, such as applying sunscreen or getting into shady areas. This is even more of an issue for those with fair skin, but also can be applicable to prevent skin damage for everyone, specifically for those who spend a lot of time outside for work (construction) or leisure activities (runners, outdoor athletes).

# Solution

Our solution is to create a wristband that tracks UV exposure and alerts the user to reapply sunscreen or seek shade to prevent skin damage. By creating a device that tracks intensity and exposure to harmful UV light from the sun, the user can limit their time in the sun (especially during periods of increased UV exposure) and apply sunscreen or seek shade when necessary, without the need of manually tracking how long the user is exposed to sunlight. By doing so, the short-term risk of sunburn and long-term risk of skin cancer is decreased.

The sensors/wristbands that we have seen only provide feedback in the sense of color changing once a certain exposure limit has been reached. For our device, we would like to also input user feedback to actively alert the user repeatedly to ensure safe extended sun exposure.

# Solution Components

## Subsystem 1 - Sensor Interface

This subsystem contains the UV sensors. There are two types of UV wavelengths that are damaging to human skin and reach the surface of Earth: UV-A and UV-B. Therefore, this subsystem will contain two sensors to measure each of those wavelengths and output a voltage for the MCU subsystem to interpret as energy intensity. The following sensors will be used:

- GUVA-T21GH - https://www.digikey.com/en/products/detail/genicom-co-ltd/GUVA-T21GH/10474931

- GUVB-T21GH - https://www.digikey.com/en/products/detail/genicom-co-ltd/GUVB-T21GH/10474933

## Subsystem 2 - MCU

This subsystem will include a microcontroller for controlling the device. It will take input from the sensor interface, interpret the input as energy intensity, and track how long the sensor is exposed to UV. When applicable, the MCU will output signals to the User Interface subsystem to notify the user to take action for sun exposure and will input signals from the User Interface subsystem if the user has put on sunscreen.

## Subsystem 3 - Power

This subsystem will provide power to the system through a rechargeable, lithium-ion battery, and a switching boost converter for the rest of the system. This section will require some consultation to ensure the best choice is made for our device.

## Subsystem 4 - User Interface

This subsystem will provide feedback to the user and accept feedback from the user. Once the user has been exposed to significant UV light, this subsystem will use a vibration motor to vibrate and notify the user to put on more sunscreen or get into the shade. Once they have done so, they can press a button to notify the system that they have put on more sunscreen, which will be sent as an output to the MCU subsystem.

We are looking into using one of the following vibration motors:

- TEK002 - https://www.digikey.com/en/products/detail/sparkfun-electronics/DEV-11008/5768371

- DEV-11008 - https://www.digikey.com/en/products/detail/pimoroni-ltd/TEK002/7933302

# Criterion For Success

- Last at least 16 hours on battery power

- Accurately measures amount of time and intensity of harmful UV light

- Notifies user of sustained UV exposure (vibration motor) and resets exposure timer if more sunscreen is applied (button is pressed)