Preliminary Design Review

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Preliminary Design Review

• February 11, 2008
• ECE 492 Spring 2008

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• MasterPC communicates to each station via RS-232
• This communication is done in parallel via the
  Octopus.
• PICs at each station will then process this
  information and send necessary commands to Rails
  Switches
• Whenever a sensor is triggered, an interrupt will
  be created that sends information back to the
  MasterPC

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• Test to meet the integrated system requirements
  for
• Powering and switching
• Operation at 16 speed levels
• The correct sensor operation
• RoHS compliance, EMI/EMC and hazmat requirements
• Documenting expandability and adaptability
• Test plan will be divided into individual test
  plans for GUI, networking and the power system

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• High risk subsystems
• RS-232 communication (PC to PIC)
• Digital to PWM on PIC
• API
• Lower risk subsystems
• GUI
• Automatic control software
• Hardware that resides on the end of the system
• Low level hardware to power circuits/rails
• Switch control hardware
• Sensor hardware

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• Direct Costs Octopus-550, PICs, PCBs, logic
  chips, serial cables, surge protector.
• Total direct costs 348.70
• Indirect Costs Labor (2250 Hours), computers,
  wires, resistors, capacitors.
• Total indirect costs 34,505.00
• Total Costs for project 34,853.70

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Automatic Control
Manual Control
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PIC Functionality SPECS

• Sensors generate interrupts that send data
  automatically to PC
• Rails are powered via PWM.
• PWM is generated via secondary PIC
• PIC keeps a timer for direction control to supply
  enough energy to coils. Implements watch-dog to
  keep voltage

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PC-to-PIC Frame Format
4-bit Rail Speed
1-bit Switch Info
1-byte Addresses
Destination Address
Source Address
R 15
R 14
R 13
R 12
R 3
R 2
R 1
R 0
S7
S6
S5
S4
S3
S2
S1
S0
8bytes
11bytes
1byte
1byte
1byte
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PC-to-PIC Communication Specs

• RS-232 Standards
• Destination and Source Addresses
• 4-bit Data/Rail
• 1-bit Data/Direction
• Speed of RS-232 shall be chosen to optimize speed
  error

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PIC-to-PC Frame Format
1-byte Addresses
1-bit Sensor Info
Destination Address
Source Address
S 7
S 6
S 5
S 4
S 3
S 2
S 1
S 0
3bytes
1byte
1byte
1byte
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PIC-to-PC Communication Specs

• RS-232 Standards
• Destination and Source Addresses
• 1-bit Data/Sensor
• Speed of RS-232 shall be chosen to optimize speed
  error

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• Political Concerns
• Environmental
• RoHS compliant
• avoiding pollution
• Funding

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• Social Concerns
• Safety
• Signs, doors, platforms
• Cost
• Transportation
• Disturbances
• Construction, use of land
• Opportunities
• Jobs

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QUESTIONS?
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• There will be testing on the following
• Packet Builder
• Packet Decoder
• Manual Control
• Automatic Control

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• There will be testing on the following
• RS-232 Communication
• Sensor Interrupts
• Rail Control
• Switch Control

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• The low level hardwares three main parts will
  each be tested individually
• The reed switches / proximity sensors
• The switching mechanism
• Train Speed

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• Functional Description
• The function of the software is to control the
  system. It includes a user interface, an
  auto/manual control and failsafe module, a packet
  builder module, and a packet decoder module.
• As a whole the software has a fairly high risk
• The user interface is at low risk
• The auto/manual control and failsafe is at high
  risk
• The packet builder is at high risk
• The packet decoder is at high risk

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• Direct Costs Octopus-550.
• Total direct costs 115.00
• Indirect Costs Labor (750 Hours), computers (8).
  
• Total indirect costs 19,500.00
• Total Costs for project 19,615.00

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Requirements Analysis Networking
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Risk Assessment Networking
RS-232 Communication This is the communication
from the computer to the 5 stations. We have
devised a crude packet structure for the data.
This subsystem is the structure of the packet and
the retrieval of these packets by the PIC
controller.
If the RS-232 does not work we need to find a
different method of data transmission. This would
mean redesigning logic inside the PIC and
possibly needing completely different hardware.
It would delay the low level hardware progress as
well as the software development. Risk Factor
PC (PC) 0.2167 .4 (0.2167 0.4) 0.53
high risk
Sensor Interrupts This subsystem will monitor
the sensors and send a packet of information back
to the PC when a sensor has been tripped. We will
generate an interrupt in the PIC when this event
occurs to make sure the data is sent and sensor
information is not missed. This subsystem will be
software written in the PIC.
Risk Factor PC (PC) 0.6 .4333 (0.6
0.4333) 0.7733 high risk
Rail Control The 4 bit data per rail will be
converted into usable analog values for lower
level hardware. The 4 bit data is a 16 value
range from 0 (rail off) to F (full speed). A
second PIC will convert this digital data to a
PWM signal for use on the rails.
Risk Factor PC (PC) 0.5 .5667 (0.5
0.5667) 0.7834 high risk
Switch Control Signals will be sent out on
parallel lines to appropriate low level hardware
that will send power to the individual coils.
There will be checks to make sure they coils are
not over powered or oppositely powered. This
subsystem will be software written for the PIC
chip.
Risk Factor PC (PC) 0.5 .5667 (0.5
0.5667) 0.7834 high risk
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• Direct Costs PICs (5), serial cables.
• Total direct costs 69.70
• Indirect Costs Labor (750 Hours).
• Total indirect costs 7,500.00
• Total Costs for project 7,569.70

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Requirements Analysis Low Level
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• -Four Tasks Overall Power, Rail Power, Rail
  Switching, Sensors
• -Overall Power Risk factor of 0.400 (Medium
  Risk)
• -Rail Power Risk Factor of 0.578 (High
  Risk)
• -Rail Switching Risk Factor of 0.337 (Medium
  Risk)
• -Sensors Risk Factor of 0.490 (Medium
  Risk)
• Most of the risk in each item is attributed to
  the high cost of failure. If any item fails, the
  entire system will not meet the requirements.
  The additional risk associated with rail power is
  due to the added complexity of using the DAC chip

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• Direct Costs PCBs (7), logic chips (28), surge
  protector.
• Total direct costs 164.00
• Indirect Costs Labor (750 Hours), wires,
  resistors, capacitors.
• Total indirect costs 7,505.00
• Total Costs for project 7,669.00