Problem Statement TelosB Charging/Metering Kit Power from 2 sources Charge AA or AAA NiMH batteries...

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

2

TelosB• Wireless Sensor Module• Low Power• For Experimentation/

Research• Open Source Operating

System-TinyOS


3

Sundance Solar Panel• Small Solar Panel• For Low Power Applications• 4V produced by solar

panels


4

Concept Sketch


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


6

RequirementsFunctional 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

Design Decomposition


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

Protection

Overcharging

Overvoltage

Back Current

8

Functional Block Diagram


9

Circuit Diagram


10

Microcontroller Justification


MSP430

PIC Arduino

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


Diode LM317Pros• 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


2:1 MUXPros

• Inexpensive• Low resistance

switch• Easily controlled• Small leakage

current

Cons• Packaging

Pros• Packaging

Cons• Larger voltage

drop

Transistor

13

TelosB Interface


Problem Statement TelosB Charging/Metering Kit Power from 2 sources Charge AA or AAA NiMH batteries...

Documents

Transcript of Problem Statement TelosB Charging/Metering Kit Power from 2 sources Charge AA or AAA NiMH batteries...