Sr. Design II
Options Considered Document
October 9, 2006
Power Line Instant Messenger (PLIM) design project by Group SD0611 seeks to
develop a communication system that keeps track of number of doses and the time the
doses were dispensed from the automatic pill dispenser at the SVEE Home in West
Fargo. In addition, this system shall be integrated with the Fridge Control currently being
developed by Group SD0616.
There has been some work done in the past by Ryan Schiermeister who was a
senior design student at NDSU. His work as documented by the ECE Wiki website
describes a design which provides disabled individuals the ability to use the internet as
tool for controlling devices around the house. The devices/appliances could be controlled
from inside or outside the residence. Technical and operational manuals are available at
The idea behind the project was for the use of handicapped or disabled individuals
to use the internet as a tool in which to control devices around the house or from
locations outside the primary resident.
Our objective is to design and construct a communication system to transmit data
over power lines. The SVEE Home considered three options:
i. Bed Vibrator
ii. Data transmitter for Fridge Control
iii. Data transmitter for the Automated Medication Dispenser.
The Fridge Control alerts a supervisor when the fridge door is opened. The Bed
Vibrator shakes the bed of a client when the smoke detectors go off. The Automated
Medication Dispenser dispenses medication for a specified number of doses and records
the number of doses and what time it was distributed.
The data transmitter for the Fridge Control sends warning messages generated by
the Fridge control to a computer. The data transmitter for the Automated Medication
Dispenser collects information such as number of doses and dosage time and sends this
data to a database on a computer.
To build a system for these various applications the Echelon Mini EVK kit will be
used. Another medium of building this system instead of the Echelon Mini EVK kit is
wireless or wired communications hardware based on non-power line communicating
devices. Building a wireless communication system would require signal processing,
sensor, transmitter, receivers and other pertinent devices. The basic idea is that one
device transmits a message/signal to another device on the same network to perform a
given task. The wired communication system would require hardwiring the various
electronics on the network, consisting of numerous wires of large lengths.
Echelon Mini EVK Kit Uses existing hardware and Major software
power lines thereby saving programming required.
time and cost in setting up Limits innovation and
new communication freedom of design. Power
hardware. line problems would result
in signal loss or distortion.
Wireless System Less clutter involved in Increases complexity of the
arrangement. system. Interference to
wireless signals such as
atmospheric and physical
barriers might impede
Wired System Less potential for physical Costly in terms of wiring
interference. materials needed to be
purchased over considerable
The above reasons are why we chose the Echelon Mini EVK Kit instead of
wireless and wired hardware communication systems. The kit includes two evaluation
boards, two input/output boards, power supplies, and a USB network interface. The
evaluation boards (PL 3120 and PL 3150) send and receive information over power lines
and also connect to peripheral devices. These boards can be connected to input/output
boards called MiniGizmos via ribbon cables. These MiniGizmos include hardware such
as a temperature sensor, a buzzer, LEDs and push buttons. The U20 Power Line USB
Network Interface connects to a Windows computer to download our application images
(computer programs) to the hardware. The power supply has two primary functions: to
provide power for the evaluation boards, and also provide an avenue to send messages
across AC power lines to other evaluation boards. To compile the application images that
we plan to build, we will use the included Neuron C compiler.
The Automated Medication Dispenser collects information (how many doses and
the time) when medication doses are distributed. A PL 3150 board in conjunction with a
MiniGizmo receives the data from the Automated Medication Dispenser and passes it
through a power line to the PL 3150 board connected to the computer. Each unit has its
own identification number or IP address, which lets us specify the location to which
information is sent. The PL 3150 connected to a computer stores the information in a
The Fridge Door Control would be configured in the same way as the Automated
Medication Dispenser with a specialized interface and application program. In addition,
an LCD display will be used to communicate messages such as error messages or last
time the fridge door opened to the programmer or user. The PL 3120 and Pl3150 boards
will be interfacing with the Automated Medication Dispenser and Fridge Door Control
using serial cables. Finally, before installation, our boards will be encased in a
polycarbonate casing. Upon further consideration, we decided not to design the Bed
Vibrator based on time and finance.
The block diagram below displays the basic layout of the communication system:
PL 3150 Board
PL 3150 Board PL 3120 Board
Medicine Fridge Door
Part Number Actual Acquired Cost Notes
of Parts Cost
LCD Display - 2 $69.95ea. $139.92 LCD Display at Fridge
Digi-Key Part Number: Control Unit
Keypad 96BB2-006-F 2 $13.13ea. $26.26
Items To Be Purchased
Echelon PL 3150 1 $95.00ea. Free Needed to substitute
present PL-3120 due to
Serial Cable (RS232) 2 - $30 Required for interface
with the Fridge Monitor
Control and Medicine
Polycarbonate Casing 3 - ~$200
Wiring $20.00 Free from NDSU
Expected Total $396.18
A Gantt chart is attached with a proposed timeline of this project. At this point,
we have decided each one of us will program and install hardware parts for an individual
Tyler Schumacher will be in charge of the PL 3150 connected to the computer.
Andrew Teevens will be in charge of the PL 3150 connected Automated
Oluwasijibomi Saula will be in charge of the PL 3120 connected to the Fridge
All work between the team members will be closely knitted to ensure a successful
completion of the design.
The primary objectives of the PLIM design group are to build a working model
communication system using the Echelon Mini EVK Kit that transmit data over power
line and supports the following application systems:
Automated Medication Dispenser – transmits dosage amounts and time dispensed
over the power lines to be stored in a computer.
Fridge Door Monitor – sends a warning message to alert the supervisor when the
Fridge is open.
A secondary objective that would be completed depending on time and budget
constraints would be to add to the above communication system:
Bed Vibrator – Simply vibrates the bed when the smoke alarm goes off using the
communication system as the link between smoke detector and the vibrator.
Additional hardware required includes:
i. Echelon PL 3150 – This EVB board will be used to interface the
Medicine Dispenser to the communication system. We need one PL
3150 at the price of $95.
ii. LCD Displays – These are the programmer/user interfaces for the Fridge
Door Monitor and Medicine Dispenser. These parts will cost $69.95ea.
iii. Serial Cables – These interface the PL 3120 and PL 3150 boards with
the Fridge Door Monitor and Medicine Dispenser, respectively. These
will cost $20ea.
iv. Polycarbonate Casings – This will be our physical housing for our
electronic boards. This would cost approximately $200 for all the