Mid-Semester PresentationSenior Design IIOctober 2, 2012

Humidity-Activated Bathroom Fan

Dontavius MorrissetteComputer EngineerDr. Mike Mazzola

Team Advisor

John AyomElectrical Engineer

Brittany BerrymanElectrical Engineer

Chris FlemingElectrical Engineer

Aaron PlunkettElectrical EngineerComputer Engineer

Team Members

Presentation Overview

Problem and Solution

Issues with high humidity in the bathroom:

•Uncomfortable environment

•Structural damage

•Mold

Problem

Humidity-Activated Bathroom Fan:

• Two device system: wall (control) and ceiling module

• Calibrates and sets initial humidity settings for room

• After humidity exceeds 15% of initial calibration, the fan will turn on

• When room returns to the calibrated level, the fan will turn off

• Pushbutton will allow for user override

Solution

Technical and Practical Constraints

Name DescriptionHumidity Resistance The wireless ceiling module must be

able to withstand up to 100% humidity.Activation Accuracy The HABF is activated when the

humidity reaches ±5% of the user set level.

Wireless Transmission The system must have wireless range of at least 30 feet.

Supply Power The control module must operate from 120VAC/60Hz.

Device Power The ceiling module is battery operated with an estimated battery life of no less than 1 year.

Technical Constraints

Type Name DescriptionManufacturability

Size The HABF control module must fit within a single-gang electrical junction box.

Sustainability Maintenance The HABF system must require almost no user interaction or maintenance.

Practical Constraints

Manufacturability: Size

The HABF control module must not exceed 2-1/4"(W) x 3-3/4"(L) x 3-1/4"(D). This will allow the HABF to:

• Fit in to a typical single gang junction box• Replace existing fan switch

Practical Constraints

[1]

Sustainability: Maintenance

The HABF must require limited user interaction relating to device maintenance.

Practical Constraints

2/23/12

System Overview

System Overview Control Module Ceiling Module

2/23/12

Refinements and Progress

•Extended Battery Life• Configure pins for low power• Minimize a wait-time• Eliminate parts

•Add Low Battery Indicator•Reduced Part Sizes•Completed PCB Design

Control Device

Schematic

Printed Circuit Board

Wall Routed

AC/DC Converter

PIC24

XBEE

TRIAC

67mm

83mm

Ceiling Device

Schematic

Printed Circuit Board

Ceiling Routed

Timer

XBEE

PIC24

Humidity SensorVREF

63mm

70mm

Device Enclosures

Control Module• The PCB for the Control Module is sized to fit

inside a single gang junction box.• The module is a drop in replacement for the

factory fan switch.

Ceiling Module• A small enclosure will be constructed to house

the Ceiling Module PCB and batteries.

[1]

Testing

TestingThe following tests will be performed on both devices following the population of both printed circuit boards:

•Control Module Power Supply Measurements

•Ceiling Module Current Draw Measurements

•Final Product

Tasks Left To Do:1. Finalize Code

2. Order PCB

3. Populate PCB

4. Test PCB

5. Design Ceiling Enclosure

2/23/12

Senior Design II TimelineAugust Septemb

erOctober Novembe

rProjectRefinementPCBDesignPCB PopulatingControl ModuleEnclosureCeiling ModuleEnclosureTesting

[1] In techMall, February 16, 2012. Retrieved from http://biotechnological/Single-Gang-In-Wall-Junction-Box-

S1-18- W-1G-p/30780.htm

[2] Honeywell. “HIH-5030/5031 Series Low Voltage Humidity Sensors”, in Digi-Key. Retrieved from http://www.digikey.com/

References

Mid-Semester PresentationSenior Design IIOctober 2, 2012

Humidity-Activated Bathroom Fan