Taylor Holmes, Jason Partin, William Rody, Malcolm Stagg

Recap of Project A biometric device which functions as: – Pedometer – Calorie Counter – Heart Rate Monitor – Temperature Monitor Data will be used by students in a physics class for calculating power and work

Objective Review Be able to measure and display heart rate Be able to measure and display temperature Be able to measure and display number of steps taken Be able to calculate work done by user Implement green energy

Hardware Accelerometers (as a pedometer) Pulse Sensor Thermistors Solar cells Li-ion battery

Surface Mount Devices (SMDs) Super – tiny parts (0.3mm x 0.5mm) We will be soldering these to our PCB by ourselves!

PCB Design 1.5” x 1.5” actual size Original Design

PCB Changes Updated our schematic to correct some errors and use an updated charge circuit Updated the PCB to pass the Design Rule Check, which is required for fabrication “Metal pours” for lower ground resistance and lower signal noise Improved parts placement Silkscreen labels for soldering

PCB Changes 1.5” x 1.5” actual size Updated Design (Submitted for Manufacture)

Coding To this point, we have: – Found a library (FatFS) for creating a file system on the flash memory – Found TI USB interface libraries – Found library code for Sharp Memory LCD – Worked with TI Code Composer Studio to gain familiarity with the tools

Enclosure Concept (from last semester) Transparent lid (acrylic or transparent polymer) 8 mm 32.5 mm 47.5 mm Rough dimensional conjecture for the interior compartment

Enclosure Accomplishments 3D-Printed a prototype enclosure Used the Stratasys Dimension Elite (communication studio)

Enclosure Challenges We need more interior room, but a less bulky enclosure! We’re currently working on optimizing internal real estate Also need to figure out what went wrong with the current printout

Pulse Sensor Low power optoisolator in a small package Specs: – Voltage = 3V to 5V – Current = 4mA at 5V

Pulse Sensor LED illuminates the skin A phototransistor senses the light’s reflection – Outputs an analog waveform to the microcontroller (Taylor’s pulse from fingertip)

Pulse Sensor Additional challenges – Filtering the signal – Coding the GPIO pins of our microcontroller

Pedometer Objectives Count within ±1 step for every 10 steps taken Eliminate as many “false steps” as possible

Pedometer Progress and Goals Parts change (ADXL-345) Waiting on PCB to run tests Problem Identification Set On/Off Mode to help accuracy More useful for experimental purpose

Thermometer

Testing hasn’t started yet Anticipate contact problem Adjustable Wrist Strap

Solar Cell KXOB22-12X1 2 monocrystalline solar cells KXOB22-12X1 instead of KXOB22-01X8 Why? – Greater IV-Curve – 18.6mW – Isc = 50mA

LTC3105 Boost Converter Step up DC/DC converter Wide Vin range: 225mV to 5V

Voltage Regulator TPS78330 TPS78330 instead of the LTC3100 Why? – 5 pins (smaller & simple) – Fixed Output (3V) – Fewer Components

To Do List & Challenges Create an effective strap for the thermistor Integrate all the systems with the microcontroller (Coding) Solder all systems and test them Create a smoother, more space-efficient enclosure