Electrical & Computer Engineering

Presentation by:Andrew FriedenMatthew Weydt

Nick SetzerTyler Dunn

PDR 2012 – Team GongSelf Sustaining Sensor System

s4

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Presentation Outline Problem Solution System Level Requirements

• Software Component Requirements & Functional Flow Diagram

• Hardware Component Requirements & Functional Flow Diagram

Power Consumption Sample Frequency Microcontroller

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Presentation Outline continued Transmitter Server Data Processing Budget Deliverables

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Problem Being Addressed Land degradation

• Depletion of soil nutrients• Inappropriate irrigation• Over fertilization• Other land pollutants

Water pollutants • Acid rain from human introduced toxins• Oxygen Depletion• Pathogens

Other environmental issues

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Solution Modular, robust device to report on current

status of environment around it Compatible with two environments: Water and

Soil Completely autonomous for convenience of end

user

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System Level Requirements The device shall be able to sense and collect

data from two types of environments: water and soil

The device shall be completely autonomously powered and operated

The device shall be able to communicate autonomously to a server via GPRS

The device shall be supported by an android software application

The software shall be able to display a graphical representation of the sensor data

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Software Component Requirements Android application shall be able to post and

receive data to and from a database Application shall be able to format and present

data from a database in a graphical user interface

Web service shall be able to provide communication between the device and the server

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Software Component: Functional Flow Diagram

MySQL Database

Android Application

Http Post

Web ServiceGPRSSIM Card /GPRS Module

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Hardware Component Requirements The energy harvester shall be able to fully charge a

battery at least 3 seasons of the year The battery shall be able to power the

microcontroller, sensor device and on board transmitter

The sensor shall be able to regularly take accurate readings of its current environment and transmit them to the microprocessor

The data shall be able to traverse from on board memory to an on board transmitter in increments of no more than 1400 bytes

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Hardware Component: Functional Flow Diagram

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Power Consumption Solar Panel supplies a maximum of 1.8 Watts at

125 mAh 2000mAh capacity battery will take 16 -20 hours

to fully charge Typical operation, 500mAh will be drawn

• 4 hours continuous use When powered on for 12 minutes:

• 5% of the battery is discharged• 48-60 minutes to recharge back to full• ~72 minute cycles• Operates for 24 hours without charging

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Sample Frequency Minimum of 72 minute sample cycles using best

case operating power, and sending after every sample

Will be at least once every 2 hours• Results in 20 samples in 40 hours without recharging

Reduced transmit rate• Delay sending until several samples have been taken• Will increase how often a sample can be taken

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Gecko micro controller Ultra low power

• 1 to 16 MHz configurable clock rate• 200µA per MHz when running

• 1.6mA @ 8 Mhz• 1250 continuous operating hours with 2000mAh battery

• 45µA per MHz Sleep Mode• 5µA Deep Sleep Mode

32Kb Flash memory UART / SPI interface GPIO Pins

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Transmitter GPRS (General Packet Radio Service)

• GSM/GPRS 850/900/1800/1900MHz • Performance for voice, SMS, Data, and Fax• Low power consumption: 1.5mA(sleep mode)• Operation temperature: -40°C to +85 °C

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Transmitter Continued Transmit using GPRS (Mobile Internet)

• 1460 byte package sizes• UART interface to Microcontroller

Use web methods for posting data to MySQL database

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Server MySql/Sql Server

• $4-$10/mo• Bandwidth: 1-unlimited GB• Web Space: 80-unlimited GB• Datacenter Locations:

• Columbus, Ohio• Chicago, Illinois

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BudgetItem Expected Cost

Solar Energy Panel $20Dc-Dc Step Up Converter $10Battery $30Soil Sensor $100Low Power Micro Controller $70Wireless Transmitter $100Water sensor $40Database $40Total $410

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Deliverables: MDR Fall 2011 Sensor / Micro controller communicating Power Supply charging battery Server and software communication System integration to be completed next

semester