Wirelessly Powered Sensor Network

Team Tesla

Damian MandaLeo Ascarrunz

Brian FairburnSarah McNamara

InternetInternet

Extended

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Base StationBase Station

Power Transmitter

Power Transmitter

GUI

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Wireless Sensor

Power / Processing Board

Power / Processing Board

Sensor Module

Base StationBase Station

ComputerComputer

Analog & Digital Lines

ANT (2.45 GHz RF)

US

B

Web-based

Interface

Web-based

Interface

REST

Power Transmitter

Power Transmitter

Power Source Selection

Rectenna

Processor Transceiver Sensors

DC-DCConverter

Battery Charging

Dual polarized microstrip patch rectenna 5.8GHz

3.8cm

3.8cm

Antenna power output is dependent on: Incident power density (here in μW/cm2) Load resistance

Optimal load resistance for peak power collection is mostly independent of incident power density

Desired Emulated Resistance: 1.2kΩ – 1.5kΩ Want to be on the right side of the curve

Power Source Selection

Rectenna

Processor Transceiver Sensors

DC-DC Converter

Battery Charging

Operates in pulsed fixed frequency discontinuous conduction mode

Resistance seen by the input varies with the output voltage

Also operates in pulsed fixed frequency discontinuous conduction mode

Requires a floating input voltage source to allow non-inverted output

Choice of parameter settings based on: expected input power level desired emulated resistance

Expected input power: 50 μW – 200 μW Emulated resistance: 1.2kΩ – 1.5kΩ

Output Voltage between 3.3 and 2.6 V Input power independent of output

30ms Active Time150 uf Storage

Power Source Selection

Rectenna

Processor Transceiver Sensors

DC-DCConverter

Battery Charging

Processor is able to switch to the backup battery by outputting the Batt_Backup signal

If battery backup is needed, Batt_Backup is set to high, and the input power source is changed to the backup battery

Using Si151DL Complementary 20-V (D-S) Low-Threshold

MOSFET

Power Source Selection

Rectenna

Processor Transceiver Sensors

DC-DCConverter

Battery Charging

As long as the output voltage from the buck-boost converter is above a set level, we want the battery to be charging

If the converter output drops below that set level, the battery stops charging

Using ISL88001 Ultra Low Power 3 Ld Voltage Supervisors Fixed-voltage options allow precise

monitoring of +1.8V, +2.5V, +3.0V, +3.3V and +5.0V power inputs

160nA supply current

Data Collection & Dissemination

Power / Processor Board

SensorIC

Micro PitchConnector

SensorID

SamtecLSHM–120–01–L–DH–A–S–K–TR

Universal Header ConnectionPin Function

1VDD2Sensor Identification Power3Analog Data 14Sensor Identification Output5Analog Data 26Power Down7Analog Data 38SPI Master Output / I2C SDA9SPI Clk

10SPI Master Input / I2C SCL11Digital Data12GND

Accelerometer CMA3000

Temperature TMP36 LM94022

Humidity Ambient Light Occupancy Pressure Force

Using asynchronous communication mode w/ modules as masters

Connection Configuration[UART]

Data Packet

Antenna Factor ANT-2.4-CHP-T Omni-directional radiation pattern 50Ω impedance – no external matching 0.5dBi Gain

Setup Get Data Process Data Transmit Data Sleep

Lock all Unused Pins Set to Input with pull down/up Resistor active

Set on Used Pins Built in UART enabled

9600 baud Built in A/D enabled Watchdog and Interrupts configured Set voltage supervisor trip point

Temperature and Accelerometer

Both are analog devices Use the Built in 12 bit

A/D convertor. Sample and Hold Possible use of the on

board DMA controller to transfer data

Determine if data is needed to be sent. New? Important?

Format Data into a useful format to send. Inputs: Data from A/D Outputs: Data sent to Transmitter

Use Built in UART to communicate with our transceiver.

Asynchronous communication at currently 9600 Baud

Input: Data from Process Data

Output: UART communication

Low Power Mode 3 CPU Disabled MCLK/SMCLK Disabled DCO's dc generator Disabled ACLK still active

Interrupt to deal with data. DMA

GUI Programmed in C# Native USB Libraries Easy to display output Knowledge of developer

Web interface Communication to a REST PHP based server Output to flash charts / PHP dynamic pages

Part Function

LTC6909 High frequency oscillator

LMC7215IM5X Low Frequency Oscillator

Si1488DH MOSFET N-CH 20V 6.1A

BAT43WS Schottky Diode

DS1608C Series(220uH)

Series Shielded Surface Mount Power Inductor

293D 330uF Tantalum Capacitor

Si1501DL Complementary 20-V (D-S) Low-Threshold MOSFET

ISL88001 3 Ld Voltage Supervisors

MSP430F2616 Processor

nRF24AP2 Nordic transceiver

ANT-2.4-CHP-T Data transmission chip antenna

Part Function

CMA3000 Accelerometer

TMP36 Temperature Sensor

LM94022 Temperature Sensor

ORIGINAL

Sensor testing boards

Initial antenna design

First power supply boards done & testing begun

Development board learning

PROGRESS

Circuit diagrams complete

Revision in development by grad students

PCB created, but have since revised converter design

Various sample code run, basic setup code created

Milestone 1 Sensor boards physically constructed Final antenna design Power supply optimization

Milestone 2 Full sensor reading & data transmission Full PCB w/ all parts integrated Computer interface developed

Expo Documentation Final board revisions

Boost Converter Needs 2.2V to start switching Can use S-882Z charge pump to pre-charge

output capacitor to 2.2V Use a battery as storage element

Names Power Xmit

Antenna Power management

Processor Sensors Data Xmit

Computer Systems

Brian X X X X X

Sarah X X X X

Leo X X X X

Damian X X X X X

Team Tesla

In order of presentation:Sarah McNamaraLeo AscarrunzDamian MandaBrian Fairburn