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 workingon optimizing internalreal estate

• Also need to figure out what went wrong withthe 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’sreflection– 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

• Measure skin temperature around the wrist• Measure before and after exercise• Uses 10k NTC Thermistor in voltage divider• 3 Equations

Thermometer

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

Solar CellKXOB22-12X1

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

LTC3105Boost Converter

• Step up DC/DC converter• Wide Vin range: 225mV to 5V

Voltage RegulatorTPS78330

• 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