Problem Statement

1. www.seniord.ece.iastate.edu/dec1201 Problem Statement TelosB Charging/Metering Kit • Power from 2 sources • Charge AA or AAA NiMH batteries • Monitor Current, Voltage and Power Deliverables • 3 Fully Functional Kits • Complete Design and Testing Documentation

2. www.seniord.ece.iastate.edu/dec1201 TelosB • Wireless Sensor Module • Low Power • For Experimentation/ Research • Open Source Operating System-TinyOS

3. www.seniord.ece.iastate.edu/dec1201 Sundance Solar Panel • Small Solar Panel • For Low Power Applications • 4V produced by solar panels

4. www.seniord.ece.iastate.edu/dec1201 Concept Sketch

5. www.seniord.ece.iastate.edu/dec1201 Users & Uses • iCube Sensors Lab • EE 423: Communication Systems Laboratory • CprE 546: Wireless and Sensor Networks • CprE 454/ComS 554: Distributed and Network Operating Systems • For Research of Energy Replenishment for Wireless Sensor Networks

6. www.seniord.ece.iastate.edu/dec1201 Requirements Functional Non-Functional • The entire system must keep power consumption to a minimum • The device must be able to receive inputs from USB or a Sundance Solar charger • Must sample power usage every 0.1 seconds • A computer must display the real time data points and store the data • At least an 8 bit ADC resolution on voltage measurements 0-3 Volts • Output the readings to the TelosB device or a PC via USB • The size of the device must be limited to 2 AA plus 2 AAA batteries and about 1 inch tall • The system should be neatly integrated • The device could have a sturdy packaging solution

7. www.seniord.ece.iastate.edu/dec1201 Design Decomposition • TelosB Charging & Metering Kit • Metering • Protection • Microcontroller • Charging • Regulator • Batteries • Measures Voltage via ADC • Back Current • Reports via USB • Provides Power • Smart Charger • Maintain Voltage • Controls Circuit • Overvoltage • Calculates Current • ADC • Overcharging • Calculates Power

8. www.seniord.ece.iastate.edu/dec1201 Functional Block Diagram

9. www.seniord.ece.iastate.edu/dec1201 Circuit Diagram

10. www.seniord.ece.iastate.edu/dec1201 Microcontroller Justification • Pros • Low Power Consumption • USB Interface • DIP Package • Pros • User Friendly • Powerful System • USB Interface • Pros • Low Power Consumption • USB Interface • Small Size • Inexpensive MSP430 PIC Arduino • Cons • Expensive Test Board • QFN Package • Cons • Larger Size • Slightly More Expensive • Cons • Higher Power Consumption • Expensive • Complex System • Large Size

11. www.seniord.ece.iastate.edu/dec1201 Regulator Justification • Pros • Inexpensive • Simple • Pros • Easy to Implement • Provides overvoltage protection • Good Voltage Control • Pros • Boosts Voltage to use for ADC • Good Voltage Control • Cons • Difficult packaging • Not adjustable (fixed voltage) Diode LM317 Buck/Boost • Cons • High Power Consumption • Cons • Expensive

12. www.seniord.ece.iastate.edu/dec1201 Multiplexer Justification • Pros • Inexpensive • Low resistance switch • Easily controlled • Small leakage current • Pros • Packaging 2:1 MUX Transistor • Cons • Packaging • Cons • Larger voltage drop

13. www.seniord.ece.iastate.edu/dec1201 TelosB Interface