Mid-Semester PresentationSenior Design IMarch 1, 2012
Humidity-Activated Bathroom Fan
Dontavius MorrissetteProgramming, Humidity
Sensor, Research
Dr. Mike MazzolaTeam Advisor
Chris FlemingTeam Technical Leader,
Power Circuit and Relaying
Brittany BerrymanTeam Manager, Power Circuit,
Wireless
Aaron PlunkettProgramming, Wireless,
Documents Lead, Website
John AyomProgramming, Wireless,
Team Members
• Problem
• Solution
• Constraints
– Technical
– Practical
• System Overview
• Approach
• Progress
• Timeline
• References
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 Description
Manufacturability 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
Control Module Ceiling Module
System Overview
Approach
Switching Comparison
Switching Comparison
How It Works:
[2]
Switching ComparisonProtocol Good Bad
Relay • Used for AC and DC circuits
• Sparking• Contacts wear
out easily
Triac • No operation noise• No moving parts to
wear out• No sparking
between contacts
• Only used for AC circuits
[2]
Switching ComparisonProtocol Good Bad
Relay • Used for AC and DC circuits
• Sparking• Contacts wear
out easily
Triac • No operation noise• No moving parts to
wear out• No sparking
between contacts
• Only used for AC circuits
[2]
Triac
Part Gate Voltage (V) Price ($)
Q2004L3 1.3 .85
Q4008L4 2.25 2.26
Q4008R4 2.5 1.25
Q6015L5 2 1.95[3]
Triac
Part Gate Voltage (V) Price ($)
Q2004L3 1.3 .85
Q4008L4 2.25 2.26
Q4008R4 2.5 1.25
Q6015L5 2 1.95[3]
Humidity Sensor
Humidity Sensor
How It Works:
Capacitive:•Consists of a substrate on which a thin film of polymer or metal oxide is deposited between two conductive electrodes
Resistive:•Consists of metal electrodes deposited on a substrate (silicon, glass, ceramic)•Sensor absorbs water vapor and ionic functional groups are dissociated
[4]
Part Accuracy (%) ResponseTime (sec)
Output
HIH-5030 ±3 5 Linear Voltage
HIH-4030 ±3.5 5 Linear Voltage
HCH-1000-001 ±2 15 Capacitance
Humidity Sensor
[3]
Part Accuracy (%) ResponseTime (s)
Output
HIH-5030 ±3 5 Linear Voltage
HIH-4030 ±3.5 5 Linear Voltage
HCH-1000-001 ±2 15 Capacitance
Humidity Sensor
[3]
Wireless
Wireless Communication
How It Works:Protocol Power Range (m) Connection Time
802.11(Wifi)
High 50 to 100 3s to 5s
802.15.4(Zigbee)
Low 10 to 100 30ms
802.15(Bluetooth)
Medium 1 to 100 3s[5]
Wireless Communication
How It Works:Protocol Power Range (m) Connection Time
802.11(Wifi)
High 50 to 100 3s to 5s
802.15.4(Zigbee)
Low 10 to 100 30ms
802.15(Bluetooth)
Medium 1 to 100 3s[5]
Wireless
Part Power Output (mW)
Sleep Current (µA)
Wake-Up Time
CC2530F32RHAT(Texas Instruments)
10 2µA 4µs
XB24-AWI-001(XBee)
1 <50 2ms
RF300(Synapse Wireless)
100 <16 1.2ms[6]
[3]
[3]
Wireless
Part Power Output (mW)
Sleep Current (µA)
Wake-Up Time
CC2530F32RHAT(Texas Instruments)
10 2µA 4µs
XB24-AWI-001(XBee)
1 <50 2ms
RF300(Synapse Wireless)
100 <16 1.2ms[6]
[3]
[3]
Progress and Timeline
Ceiling Module
1. Variable voltage is sent to the microcontroller
2. PIC receives analog voltage and sends value to XBee
3. XBee sends wireless data to the control module
Wall Module
1. XBee receives data from ceiling module
2. Microcontroller receives value from XBee
Output Data
2/23/12
•Output from the control module microcontroller
•Proves successful wireless transmission of data from the ceiling module to the control module
Example Code
2/23/12
Triac Circuit
2/23/12
The Triac circuit utilizes a low DC voltage to turn switch 120 V AC.
Power Circuit
Timeline
[1] In techMall, February 16, 2012. Retrieved from http://biotechnological/Single-Gang-In-Wall-Junction-Box-S1-
18-W-1G-p/30780.htm
[2] “How Dimmer Switches Work,” in howstuffworks, February 18, 2012. Retrieved from http://home.howstuffworks.com/dimmer-switch3.htm
[3] In Digikey, February 17, 2012. Retrieved from http://www.digikey.com
[4] “Resistance Change Type Humidity Sensor Units with High-Accuracy Detection and Output Control,” in TDK, February 23, 2012. Retrieved from TDK.co.jp/tfl_e/sensor_actuator/CHS/index.html
[5] “How does ZigBee compare with other wireless standards?” in Software Technologies Group, February 24, 2012. Retrieved from stg.com/wireless/ZigBee_comp.html
[6] “SNAP Components: Synapse RF Engines,” in Synapse, February 24, 2012. Retrieved from synapse-wireless.com/snap-components/rf-engine#docs
References
Mid-Semester PresentationSenior Design IMarch 1, 2012
Humidity-Activated Bathroom Fan