ECE411_FALL2011
HOMEWORK 3
REQUIREMENTS DOCUMENT
Team members: Thang Vo, Michael Lowe, Jules Alfani, Anh Ngo
Needs Requirement
Greenhouses are important for growing vegetation in non ideal climates. While greenhouses protect
plants from harsh weather and pests, if not properly monitored the artificial environment can cause
decay and disease among the plants. Because greenhouses are controlled environments for plants, it is
very important to monitor the environmental data in real-time, as well as provide information from
recent time periods.
Objective
The goal of this project is to design a system that can provide current temperature and humidity to a
user and provide them data from certain periods of time, in case they need to troubleshoot problems
with the greenhouse.
Product Design Specification
Marketing
Requirements
Engineering Requirements
Justification
Performance
4
4
4
4
5, 6
The system should detect humidity from
0 to 100% RH (relative humidity).
Should be able to measure temperatures
between 0° and 40° C
Functionality
The system will populate the
temperature and humidity into a
database every 10 minutes
The system will display the temperature
and humidity on an easy to read LCD.
Energy
The device should be able to run with the
supply power of 4.5V-5.5V
In a typical greenhouse
environment a humidity of
above 80% for a long period of
time should be avoided
A typical greenhouse should not
get below 10° C and above 30° C
It will be useful for a gardener to
know for what periods of time
the environment is out of range.
The system needs to provide real
time data for the user.
This requirement is important to
make the device portable and
compact. It is based on the USB
standard
5, 6
The average power consumption of the
microcontroller should be about 3.3mW
(at 1MHz, 3V and 25oC)
4, 5, 6
The peak current going through the
microcontroller must be less than 100mA
1, 2, 5
Maintainability
Every electronic component assembled in
the device must be easy-to-find
4, 5
Maintenance-period requirement should
be less than two months
2
The mean time for fixing common errors
should be less than half a day
1, 2
1, 7
1, 2
4, 5
1, 3
5
7
Manufacturability
All of the elements should be chosen
from one company without any change
of product line
The device must interact well with
Window or Unix systems
Design tools, assembly tools and testing
tools have to be common
Operational
3.3mW at such conditions is an
intermediate value that would
reflect normal operation.
To guarantee that the device as
well as the USB port are not
overwhelmed
This is critical to assure a quick
fix when malfunctions occur
To make the device long-lasting
and competitive to other similar
devices
To ensure the sustainable
operation when the device is set
in place
This help us to take advantage
of large-quantity orders and
makes the device sustainable
The requirement guarantees
that users can easily work with
the device and the device itself
can be widely distributed
To optimize the process flow
and reduce the cost of products
The device is sustainable in temperature
varying from -10 to 50 degrees C
temperature range and humidity ranges
from 0-100% RH
The condition for greenhouse
using the device is
Temperature: 10-30 degrees
Celsius
RH: < 80 %
Area of PCB should be no more than
16in2
PCB fab house only provides
student the maximum PCB area
of 16in2
Reliability
The lifetime of the device should be at
least 1 year
Usability
Interface is a user friendly window
application.
Based up on similar devices
outside market
Does not require any training or
tutorial on using the application.
Economic
1
The costs for developing or producing
the system (parts) should not exceed
$100.
This is based upon, each student
member in the team, financial
budget.
Health and Safety
8
The system will not expose humans to
unhealthy levels of electromagnetic
radiation.
9
The system will use only UL (Underwriter
Laboratory) approved components.
The IEEE C95.1-1991 Standard
for Safety levels with Respect to
Human Exposure to Radio
Frequency Electromagnetic
Fields is 3 kHz to 300 GHz.
UL (Underwriter Laboratory) is a
North American component
certification program that
requires component parts are
suitable for installation and meet
the Conditions of Acceptability.
Environmental
9, 10
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
50% of the component parts should be
recyclable, able to be repaired and
reused in similar product.
Oregon is an environmental
friendly state with clear
regulation on recycling and
waste management.
Marketing Requirements
Should be low cost
Easy to assemble and maintain
Should be compact
Can measure and display accurately
Durable and a long life span
Low power consumption
Handy interface
Safety
Legal
Contribute to environment protection
http://njveg.rutgers.edu/assets/pdfs/ajb/Temperature%20Management.pdf
http://www.howitworks.net/how-a-greenhouse-works.html