1. 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 www.seniord.ece.iastate.edu/dec1201 1

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

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

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

5. 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 www.seniord.ece.iastate.edu/dec1201 5

6. Requirements FunctionalNon-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 6 www.seniord.ece.iastate.edu/dec1201

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

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

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

10. Microcontroller Justification www.seniord.ece.iastate.edu/dec1201 10 MSP430PICArduino Pros Low Power Consumption USB Interface Small Size Inexpensive Cons Expensive Test Board QFN Package Pros Low Power Consumption USB Interface DIP Package Cons Larger Size Slightly More Expensive Pros User Friendly Powerful System USB Interface Cons Higher Power Consumption Expensive Complex System Large Size

11. Regulator Justification www.seniord.ece.iastate.edu/dec1201 11 DiodeLM317 Pros Inexpensive Simple Cons High Power Consumption Pros Easy to Implement Provides overvoltage protection Good Voltage Control Cons Expensive Buck/Boost Pros Boosts Voltage to use for ADC Good Voltage Control Cons Difficult packaging Not adjustable (fixed voltage)

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

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