1

Emergency Exit DetectorTeam Kelly

MDR Presentation

Team MembersLeonardo Mascarenhas

Ernald NicolasKrystina PyszDavid Vega

2

Motivation

September 11, 2001

South Tower• four civilians escaped on Stairwell A from 80th floor or

above• one specific evacuee switched from one impassable

staircase to a clear one

North Tower• one group below the fire repeatedly called 911 asking

for the fire’s location• this group is presumed dead because 911 advised them

to remain on the 83rd floor

3

Existing Sensor Networks Wireless fire sensor networks

commercially available and commonly found in high-rise buildings.

In a fire emergency, these sensors relay their data to a fire panel display accessible to authorized personnel.

Sensors update the fire panel periodically to indicate their ongoing operation.

This SDP project will take the fire panel information, process it, and relay suggestions to the building occupants.

4

Fire Control Panel

Routing Algorithm PC

FM Transmitter

Block Diagram

Wireless

Wire

FSM (A/D)

Exit Warning Devices

FM Receiver

Light Displays

Device 1

FSM (A/D)

FM Receiver

Light Displays

Device 2

FM Receiver

Light Displays

Device 3

Digital Logic

Digital Logic

Digital Logic

5

MDR Specifications

Detailed block diagram of routing algorithm design. One wireless transmitter capable of sweeping through four

different frequencies.• Transmitter sweep will consist of sine waves without

modulation.• Transmitter will reach receiver at a distance of at least

10 meters.

One wireless receiver unit attuned only to one particular broadcast frequency.• Receiver will be able to switch its light display off, green,

and red.• Receiver will not respond to frequencies outside of its

pass-band.

Algorithm

1. Flowchart of Algorithm2. Example Scenario3. Algorithm and Transmission

7

Algorithm Light Display Code:

• Red (R) = Heat detected• Green (G) = Clear• Yellow (Y) = Smoke detected

Main Idea of Algorithm: Priority/level of danger from Highest to Lowest:

• Heat/Fire, Smoke, Clear• Red, Yellow, Green

Current floor’s status will be analyzed before, and compared with, the previous floor’s status. The color of light displayed will depend on priority.

8

Algorithm Flowchart

Set floor 1 lights to conditions

sensed

Determine floor 2 (or current floor) lights based on its own conditions and floor 1 (or previous floor) conditions

If 2nd flr has smoke:If 2nd flr is clear: If 2nd flr is on fire:

Is 1st flr on fire?

Is 1st flr on fire?

GreenYellow

N

NY

Y

RedYellow

YN

Red

1st flr have smoke?

Red

9

Example Scenario 4 Story Building 3 Stairwells/Exits: A, B, C

Light Display Code:• Red (R) = Heat detected• Green (G) = Clear• Yellow (Y) = Smoke detected

Main Idea of Algorithm: Priority/level of danger from Highest to Lowest:

• Heat/Fire, Smoke, Clear• Red, Yellow, Green

Current floor’s status will be analyzed before, and compared with, the previous floor’s status. The color of light displayed will depend on priority

10

Algorithm and Transmission

Transmission to change light color will occur only if status of sensor has changed from previous check.

Plan: Save matrix of previous sensor data and compare with new matrix to see which have changed.

11

FM Transmitter

What is new from PDR design?• Changed from FSK chip to FM chip.

• FM fits our needs better.• We are transmitting simple data.

• Input will be a sum of sinusoidal waves.• It will transmit different messages at the same fc.• Addition of microcontroller to generate desired message.

What is the Chip we are using?• The Motorola MC2833 (Low Power FM Transmitter).

• Has an output power in the range of 5dBm to 10dBm. What the design look like?

12

FM Transmitter design

13

FM Transmitter cont’d

What frequency are we planning to use?• We want fc equal to 49.7MHz (US Army range).

Why?• Breadboard has problems to handle VHF.• RLC components are easier to buy.• FM radio stations range is full and has very strong signals. • It is legal to transmit in any FM range as long as we output less than 10dBm (10mW) in power.

What is the problem with the transmitter?• Have the design ready, and all components. However, the Motorola MC2833

Chip has not arrived. What have we done instead?

• Concentrated on other parts of project.• Worked on alternative FM transmitter. However, we are currently debugging the

tank component of the design.

14

FM Transmitter in the Lab

15

Receiver Unit What is missing?

• Same problem as transmitter, the Motorola MC3362 Chip has not arrived. We have the receiver design ready, and all components.

Why is it mostly complete then?• The change from FSK to FM also changed the receiver unit.

What is new?• Now the receiver unit is composed of:

• FM receiver• Digital logic:

• BPF, Analog to Digital conversion, CPLD.

• Light display. What is done?

• The Digital logic (BPF, Analog to Digital conversion, CPLD), and the Light display are completed and working.

16

Narrow BandPass Filter

Radian Frequency Hertz

0

R5

300k

V8-5Vdc

R83k

C5

26.5n

R71200k

V

0

U2

uA741

3

2

74

6

1

5+

-

V+

V-

OUT

OS1

OS2

V7

5Vdc

0

0

C4

26.5n

VV11

20mVac

0Vdc

17

Frequency Sweep Bandwith of 20 Hz 90Hz – 110Hz

100.9 Hz

The “filtered” 100 Hz signal is next inputted into an amplifier stage…

18

Amplifier/Schmitt Trigger

19

Plots of different Stages

20

CPLD

Signal Timing Analysis for State Transition:

1)Set the specs for when a signal is definitely pulsing

2)Set the spec for when an old signal has ended and

a new signal has begun (signifying a change in state)

21

Timing Analysis

1) one period of HI’s of shortest period (1/250Hz – 4ms)

2) three cycles worth of LO’s of longest period (1/50 Hz – 20ms) for delay of consectuive transmissions

22

Summary

Routing algorithm logic completed, actual code needs to be written.

Preliminary transmitter and receiver designs completed, awaiting component ICs.

Receiver logic completed, and component LED for light display chosen.

Less than $100 has been spent, and thus the project is well under budget.