TEAM 2 Solar-Powered Multi-Seat Computer Kiosk for Tanzanian Classrooms ECE Facilitator Jian Ren Telecomm Facilitator Kurt DeMaagd UDSM Solar Advising Professor Dominick Chambega UDSM Telecomm Advising Professor Aloys Mvuma Management Jakub Mazur Web Josh Wong Document Ben Kershner Presentation/Lab Eric Tarkleson Telecomm Joe Larsen Telecomm Tor Bjornrud UDSM Telecomm Victor Crallet Request for Proposal – October 13 th , 2008 Sponsored By: In Cooperation With:
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TEAM 2 - egr.msu.edu · Web viewTEAM 2Solar-Powered ... The design team preceding ours built a solar powered computer system that can be deployed in a relatively durable building.
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TEAM 2Solar-Powered Multi-Seat Computer Kiosk
for Tanzanian Classrooms
ECE Facilitator Jian RenTelecomm Facilitator Kurt DeMaagd
UDSM Solar Advising Professor Dominick ChambegaUDSM Telecomm Advising Professor Aloys Mvuma
Management Jakub MazurWeb Josh Wong
Document Ben KershnerPresentation/Lab Eric Tarkleson
Telecomm Joe LarsenTelecomm Tor Bjornrud
UDSM Telecomm Victor Crallet
Request for Proposal – October 13th, 2008
Sponsored By:
In Cooperation With:
Michigan State University University of Dar es Salaam
Ben Kershner, 10/13/08,
First name obtained via Google.
Ben Kershner, 10/13/08,
Should I include these team members.?
Ben Kershner, 10/13/08,
Should I include these team members?
Ben Kershner, 10/13/08,
First name obtained via Google.
Executive SummaryWith the increasing proliferation of affordable, reliable personal computers
into the marketplace, there is a great demand to develop affordable personal
computers for remote and undeveloped areas. One such potential region is rural
East Africa, specifically Tanzania. Before deploying a computer system into such
harsh conditions, several obstacles must be overcome, including source of
electricity, telecommunications, and the savannah climate. The Lenovo Corporation
has tasked this team to develop a solar-powered computer workstation that can
accommodate up to eight users. The solution must be robust enough to withstand
the harsh environment with as little technical maintenance as possible, yet still be
affordable for rural schools.
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Table of Contents
EXECUTIVE SUMMARY 2
TECHNICAL SPECIFICATIONS 4
INTRODUCTION 4BACKGROUND 4DESIGN SPECIFICATIONS 5DESIGN CRITERIA 5CONCEPTUAL DESIGN 6PHASE I: POWER ARCHITECTURE 7PHASE II: SYSTEM ARCHITECTURE PROTOTYPES 8PHASE III: POWER MANAGEMENT 14PHASE IV: CONTENT 14
PROJECT MANAGEMENT 15
DESIGN TEAMS AND ROLES 15
REFERENCES 16
IMAGES 16NOMENCLATURE 16
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Technical Specifications
IntroductionThe primary goal of this project is to help promote education in developing
countries by providing grade schools with electronic resources. There are a variety
of other groups that have already initiated solutions to this problem. The most
prominent group is the One Laptop Per Child Association (hereinafter referred to as
OLPC), which has created a cheap, durable laptop known as the XO-1. Other groups
such as the Center for Scientific Computing and Free Software (hereinafter referred
to as C3SL) have made significant strides in reusing older computers for schools;
however, both of those programs have some significant drawbacks.
BackgroundThe primary competitor identified is the OLPC. The OLPC Association is
dedicated to producing low cost laptops and distributing them to low-income areas.
There exist several problems with the program, including the per-deployment cost
and deployment. The original intent was to deliver a laptop to every child for a cost
of $100 per device. The program, however, is unable to deliver the laptop at the
$100 target; in fact, the cost to donate a system is almost $200. Deployments also
require a minimum commitment of 100 laptops. This represents a very significant
financial burden, though once deployed, the XO-1’s are extremely rugged PCs and do
not depend on any external power sources. Once deployed, it is difficult to integrate
multiple PCs into a cohesive learning environment, and this takes away from
educating the students.
C3SL’s solution integrates into school systems better, and was widely
deployed in the Paraná Digital project. This project involved having the multiple
terminals running off of a single computer in multiple schools. This program has
been very successful and shows great promise, but there is a critical flaw. The
program is entirely software, and this software was intended to run in a classroom
equipped with at a minimum basic utilities, such as power and internet-
connectivity.
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Our solution is to integrate the OLPC's ruggedness and the C3SL's novel
software solution into one robust package. The design team preceding ours built a
solar powered computer system that can be deployed in a relatively durable
building. They assembled a solar panel, battery, and a charge controller into a self-
contained solution, such that deployment in a wide variety of climates and locales is
possible, but they were unable to decide on the computer system. Our primary goal
for this project of integrating the work of our predecessors with a computer system
that is suitable for educating youth, regardless of regional or socio-economic
boundaries.
Design SpecificationsThe core of the design is a single computer powering multiple dumb
terminals. There are many ways to create a dumb terminal; these will be discussed
later in the proposal. The entire system is connected to an AC/DC inverter, which is
powered by a large, deep-cycle battery. The battery is charged via a photovoltaic
panel. There is independent monitoring circuitry to ensure the system is functioning
properly, which can gather data to recommend ways of improving system
performance as well.
Once the prototype is complete, we will install it in a school in Tanzania.
Lenovo will also be able to mass-produce the system and package it for sale. A
variety of organizations, such as governments or humanitarian groups, can then
purchase a base station and add any number of terminals. Given that each station
functions independent of a power source or communications source, it can be
shipped to any location and quickly be installed. Once the system is set up, it will
require minimal maintenance, and limited software support will be provided over
the Internet.
Design Criteria The following requirements are established to decide the feasibility and rating
the desirability of the conceptual designs:
Stability/Reliability
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o The system is to operate in a remote area with as little maintenance as
possible.
Power Consumption
o Solar power is the single power source for the system therefore
minimal power consumption is a priority.
Construction Difficulty
o The team has a limited time frame to complete the project and have it
packaged ready for deployment.
Lenovo Hardware
o Implementing the sponsor’s hardware into the system will help keep
costs down.
Cost
o The system is to be implemented in schools with a very limited
budget, the lower the cost the greater the chances of system
deployment.
The criteria (specifications) to be used in the matrices for deciding the
feasibility and rating the desirability of the conceptual designs are still being
developed, and at least one conceptual design.
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Conceptual DesignThe conceptual design for this project is split into four phases. The first is
power system design, which for the most part was completed by the previous
semester’s team, but was still reviewed by our team. The next phase is system
architecture, i.e. how the computers and workstations are set up. After that, we
covered power management, and finally, content.
Phase I: Power Architecture
Figure 1: Power architecture flowchart.
Given that the power architecture was in place when the team received the
project, and that the schedule and budget are limited, we decided to leave it in its
current configuration. A meeting was convened and possible improvements to the
architecture were discussed, which could be considered for the production model.
Starting from the top down is the solar panel. There are two qualities to
consider: efficiency and price. The panel chosen should provide the highest wattage
per dollar spent, giving the greatest value. Several cheap, low efficiency panels
would be preferable to a single high efficiency panel if they provide a higher wattage
per dollar. They would also be more robust; e.g. a single panel could fail and the
system would loose a portion of its power generation capabilities, rather than its
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sole source of power. The panel currently used is the Kyocera KC85TS 85W panel,
which operates at 16% efficiency (see Figure 2 for value).
A mid-range standard charge controller (CirKit SCC3) is used to regulate the
voltage from the solar panel to the battery. The standard charge controller could be
improved by replacing it with a maximum power point tracker (MPPT), which is
more capable of handling the surplus voltage (> 15V) generated by the solar panel
in high irradiance conditions (i.e. direct sunlight).
The battery purchased for the project is a 225 Amp-Hour marine deep-cycle
battery, chosen for its large capacity and ability to delivery current at a constant
voltage for an extended period of time. As in the solar panel, the capacity and price
are the two key qualities in consideration (see Figure 2 for value), the life cycle is
also very important. It tends to not vary throughout the industry with deep-cycle gel
batteries intended for solar use, and therefore did not garner much consideration.
This entire system feeds a 1750W power inverter, which ideally operates at
90% efficiency. From here power can be provided to anything that can operate at
115VAC. This may be an issue depending on the area of deployment; a majority of
the world operates at 220-240VAC, thus interfacing other components into the
power system (such as cell phone chargers) could prove to be dangerous.
Figure 2: Component cost/value table.
Component Model Number
Capacity Efficiency Cost Value
Solar Panel Kyocera KC85TS
85W 16% $468.75 0.181 W/$
Charge Controller
CirKit SCC3 N/A N/A $44.95 N/A
Battery Deka Domintator 8G8D
225AH N/A $399.07 0.564 AH/$
Power Inverter XPower 1750 Plus
1750W 90% N/A N/A
Phase II: System Architecture PrototypesThe ECE team considered four ideas for the architecture of the system.
During a whiteboard brainstorming session, each prototype was sketched, the pros
and cons were weighed, and a cost was estimated, as shown in Figure 3.
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Figure 3: System architecture advantages, disadvantages, and estimated cost table.
Tanzania (University of Dar es Salaam)Member RoleDominick Chambega Solar Advising ProfessorAloys Mvuma Telecommunications Advising ProfessorVictor Claret Telecommunications
References
ImagesAll images on the coversheet were obtained from Wikipedia:
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The Lenovo logo is owned by the Lenovo Group and is being used under the fair-use rationale.
The Michigan State University logo is owned by the Michigan State University Board of Trustees and is being used under the fair-use rationale.
The University of Dar es Salaam logo is owned by the University of Dar es Salaam and is being used under the fair-use rationale.
Nomenclature C3SL – Center for Scientific Computing and Free Software. CPU – Central Processing Unit, refers to the main processor chip on a computer
motherboard, not the computer as a whole. COTS – Commercial Off The Shelf, describes hardware or software that may be
purchased rather than designed and built. MPPT – Maximum Power Point Tracker, a style of solar charge controller. multi-seat – A type of system architecture in which many workstations are built
onto a single machine. PIC – The company that produces the microcontroller used, may also refer to the
microcontroller itself. PV – Photo-Voltaic, i.e. solar panel. PXE – Pre-boot eXecution Environment, a manner of booting computers over the
network without a locally installed operating system. OLPC – One Laptop Per Child. OSS – Open Source Software. system architecture – The term used within this document to describe how the
style in which the workstations are deployed. thin client – A client computer that relies on a central server for a majority of its