Transcript Slide 1

Group 14
Michael Trampler EE
Javier Arias EE
Ryan Kastovich EE
Genaro Moore EE
Overview
 Heating
 Ventilation
 Air Conditioning
 Some provide advanced features such as humidity
control and CO2 monitoring/control
 Scheduling and adaptive set-points will allow the user
to reduce the systems run time.
 Run time data logging will give the user a better
understanding of the systems activities
Motivation
Increased cost of electricity
Great cost of commercially available HVAC
controllers
Limited feature set of commercially available
HVAC controllers, especially web enabled
controllers
Objectives
 Accurately read temperature and relative humidity both
inside and outside building.
 System management through web app
 Scheduling capabilities
 CO2 monitoring for a gauge of air quality
 Zone control
 Expandable to multiple zones
 Wireless connectivity to RSM
 Reduction of energy consumption due to scheduling and
set-point control
 Simple and easy installation with minimal wiring.
Project Specifications
 Main Controller
 Control up to 8 zones
 Wireless connectivity to RSM at a minimum of 50ft
 Web Interface
 Host at least 5 users simultaneously
 Manage week long schedules for each zone
 Track duty cycle of heat pump to an accuracy of 0.1%
 Display status of up to 8 zones simultaneously
 RSM
 Temperature ±0.125°C
 Humidity ±5% relative
 CO2 At least ±500 ppm
 1.5 month battery life
System Block Diagram
Plant Block Diagram
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Plant Specifications
 Need to supply 24VAC to drive the different
components
 Be able to support up to 8 zones
 Continuous uptime for 2 months
Heat Pump
 Various types: single stage, multi-stage, variable
compressor, variable fan, oil, gas, etc…
 Design for single stage because most common in FL
 Air handler indoors, compressor outdoors
Heat Pump Components
 Reversing Valve (changeover)
 Controls heating/cooling mode
 Compressor
 Supplementary heat
 Electric heating coils
 Fan (Air Handler)
 Automatic – turns on when ever the whole unit is on
 ON (continuous) – on regardless of the state of the unit
Control (Hardware)
 74HC595 (from TI)
 8-bit serial input shift register
 Serial or parallel output
 Vcc: -0.5V - +7V
 Needs only 3 inputs: data, latch, and clock
 Outputs 0 – Vcc (V)
Control (Hardware) Continued
 MAC97 Triac
 Connected to 24VAC supply to drive the heat pump
components
 Can handle up to 600V
 2V max gate trigger voltage
 0.66V typical trigger voltage
Heat Pump Control Schematic
Plant Block Diagram
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Damper Control
 Dampers act as a door for air to flow through ducts
 Dampers come either N-O/N-C
 Require 24VAC
 Utilize normally open 2 position dampers
 Makes system modular
 Design for up to 8 zones
 74HC595 Shift Register
 8 outputs for 8 zones
 MAC97 Triacs
 8 triacs for the 8 zones
Damper Control Schematic
Output Board
 The plant control will be implemented onto a PCB
separate from the Main Control Unit
 Responsible for shift register and triac control
 It will communicate wirelessly between the output
board and the Main Control Unit
 1 MSP430 will be utilized to drive the shift registers
Output Board Specifications
 MSP430G2553
 1.8 – 3.6 V supply
 230uA active consumption
 Drives triacs and shift registers
 74HC595 Shift Register
 MAC97 Triacs
 UART connectivity to Wireless Module
Main Control Unit (Hardware)
 Control software of the plant will be housed in the
MCU
 Once the state of the HVAC system is determined, the
MCU will send the state to the Output Board which
will take care the rest
 Also in charge of gathering data from the Remote
Sensor Modules
 Communicates with Web App
 Stellaris LM3S8962 Microcontroller
System Block Diagram
Temperature/ Humidity
Hardware
Using a digital Temperature/Humidity Sensor
from Honeywell
HIH-6130
 Accurate to 4% RH
 Operates from 0-100% RH
 Accurate to .025 C
 SPI
 3.3V supply
 0.6-0.75mA current consumption
CO2 Measurement
 MC811
 Low cost CO2 measurement
 Analog output voltage which requires amplification
 Sensitive from 250ppm to 10000ppm
 Requires 200mA at 6V
 LMC660
 Very High input impedance FET op-amp
 Used to amplify the output to a usable level for the
microcontroller
User Interface
 One 1.8 inch TFT color display
 16 bit color resolution
 160 x 128 pixels
 SPI interface
 4 push buttons
 Used for simple input
Wireless Communication
Specifications
 MSP430G2553
 UART Connectivity to modules
 CC110L Transceiver
 Anaren booster pack
 Frequency Band: 779 – 928 MHz
 200nA sleep mode consumption
 SPI connection between transceiver and MSP
 Creates single code base for wireless communications
System Block Diagram
Stellaris Internet Connectivity
 Modified lwIPhttpd (web server) implementation provided with Stellarisware.
 CGI adapter provided by Stellarisware sample code.
 unsigned long FindCGIParameter(const char *pcToFind, char *pcParam[], int iNumParams)
 Searches the list of parameters passed to a CGI handler and returns the index of a given parameter
within that list.
 long GetCGIParam(const char *pcName, char *pcParams[], char *pcValue[], int iNumParams,
tBoolean *pbError)
 Searches the list of parameters passed to a CGI handler for a parameter with the given name and, if
found, reads the parameter value as a decimal number.
 unsigned long EncodeFormString(const char *pcDecoded, char *pcEncoded, unsigned long
ulLen)
 Encodes a string for use within an HTML tag, escaping non alphanumeric characters. This function
encodes a string, adding escapes in place of any special, non-alphanumeric characters.
 unsigned long DecodeFormString(const char *pcEncoded, char *pcDecoded, unsigned long
ulLen)
 Decodes a string encoded as part of an HTTP URI. This function decodes a string which has been
encoded using the method described in RFC1738, section 2.2 for URLs.
Web App Hosting
Stellaris LM3S8962
Beaglebone Google App Engine
Clock Frequency
50 Mhz
720 Mhz
N/A
RAM
64 KB SRAM
256 MB DDR2
N/A
microSD
N/A
Yes
Linux
Apache/Lightt
pd
C/Python/PHP
/Perl/Java
CSV/SQL
~$90 (dev
board)
N/A
N/A
Storage
Ethernet
Operating System
HTTP Server
256 KB Flash +
microSD
Yes
None
C (Custom coded
using lwIP)
Application Programming
C
Data storage
CSV
Cost
~$90 (dev board)
N/A
Python/Java/Go
Datastore
N/A
End-to-End Connectivity
Web App Hosting
 Google App Engine
 Cloud computing: Platform as a service
 Hosting on Google's infrastructure
 Google Cloud = Distributed resources
 No need to manage server
 Application development:
 Python
 Java
 Data storage: Google Datastore
Python/ Java
Is it Free?
Learning Curve
Does it need to
compile?
Other tools?
Built In Docs?
Script?
Difficulty of
Implementation in the
Google App Engine
Python
Free and Open Source
Simple Syntax
Java
Free and Open Source
Lacks Simple Syntax
No
Wide range of tools and
libraries
Yes
Yes
Yes
Large range of libraries
No
No
Very straight forward
implementation
Not very straight forward
Webapp2
 Lightweight framework
 Flexible and easy to extend
 Built into Google App Engine
 WSGI Adapter
 Interface between web server and web application
 Also responsible for handling uncaught exceptions
 Templating
 HTML embedded in code is messy and difficult to maintain.
 Using a templating system we can dynamically generate
portions of the HTML and embed special placeholders in the
HTML files to indicate where the generated content should
appear.
 Django templating engine
Webapp2 Handlers
 handlers.ReadingsHandler
 handlers.ZonesHandler
 handlers.UsersHandler
 handlers.PlantsHandler
 handlers.SchedulesHandler
 handlers.ThermostatsHandler
 handlers.LoginHandler
 handlers.ReportsHandler
Google Datastore
 Horizontally distributed database based on Google's
Bigtable
 Manages very large sets of structured data
 Allows for scaling of applications as they receive more traffic
 Object datastore
 Objects are called entities
 Entity kinds (classes) Modeled in Python or Java
 Supports atomic transactions
 Python and Java APIs
 Google Query Language: flexible but not as much as SQL
Data Models
 Every entity has its own unique key property
 Implicitly created by the App Engine during entity creation.
 Includes the entity kind and a unique numeric ID that is automatically
assigned.
System Block Diagram
Operating Environment
Development Platform:
Google App Engine
 Backend Programming Language:
Python
 Primary Client-Side Scripting Framework:
jQuery Mobile (JavaScript)
Why jQuery Mobile?
 HTML5 and CSS3 Compatibility
 Works on both Android and iOS
 Professional Layout for PC, Tablet and Mobile Devices
 Compatibility with Firefox, Chrome, Safari and others
 Allows for rich touch screen interfaces for mobile
devices
Simple Splitview
 jQuery Mobile plugin which utilizes white space by
splitting the menu options on the left side and the
displayed selection on the right
 A PC/ Tablet layout will have a split in the middle
between these two parts of the web app to fill in the
white space
 A Mobile layout will fit the menu options to the
screen and upon user interaction will display the data
PC/ Tablet Landscape View
Mobile View
Web App Use Case Diagram
Scheduler
 Standard HVAC systems typically do not include
embedded schedulers for their users
 User will be able to adjust Set times, Humidity and
Temperatures for specific zones in the system
 Users will be able to adjust their scheduler for a week
at a time
 Coded using Python and JavaScript
Output Power Supply
 Use readily available 24VAC supply
 Most commercial HVAC controllers use a 24VAC
supply as standard
 Output 24VAC for HVAC system control
 Use Full Wave rectifier and 3.3V switching
regulator for logic level power
OKI-78SR-3.3
DE-SW033
TPS62111R
Input Voltage
Range
7-36V
5-30V
3.3-17V
Efficiency
75-90%
83%
80-95%
Current
1.5A
1.0A
1.0a
Cost
$4.35
$15.00
$3.72
Main Controller Power Supply
Use readily available 17V Laptop power supply
3.3V switching regulator for logic level power
OKI-78SR-3.3
DE-SW033
TPS62111R
Input Voltage
Range
7-36V
5-30V
3.3-17V
Efficiency
75-90%
83%
80-95%
Current
1.5A
1.0A
1.0a
Cost
$4.35
$15.00
$3.72
RSM Power Supply
RSM will use 4 AA batteries to supply the
CO2 sensor’s heaters, as well as the op-amp’s
Vcc
3.3V regulator will be used for the sensors,
the wireless communication and the main
microcontroller
Progress
Progress
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Plant Control
RSM
Database
Web App
PCB
Wireless Module
Project Distribution
Plant Control
RSM
Database
Web App
PCB
Michael
5%
85%
5%
5%
75%
Javier
15%
5%
55%
35%
5%
Ryan
5%
5%
35%
55%
5%
Genaro
75%
5%
5%
5%
15%
Budget
Item
Sensor Microcontroller
Humid/ Temp Sensors
CO2 Sensors
Graphical Display Unit(s)
Input Peripheral Suite
RSM Power Supplies
Main Controller Power Supplies
RF Module
PCB
Main Controller
Triacs
Grand Total
Quantity
8
4
4
4
4
4
1
6
5
2
16
Price (of each)
$1.00
$15.00
$20.00
$20.00
$5.00
$10.00
$15.00
$15.00
$33.00
$100.00
$2.00
Expected Budget
$8.00
$60.00
$80.00
$80.00
$20.00
$40.00
$15.00
$90.00
$165.00
$100.00
$32.00
$690.00
Budget so Far
$0.00
$20.00
$40.00
$30.00
$10.00
$10.00
$20.00
$70.00
$165.00
$100.00
$20.00
$485.00
Issues/ Concerns
Wireless Node Limit
Collision During Wireless Transmit
Duplicity of commands from Google App Engine
to Stellaris
Designing a Scheduler
No touch event response on Google Chrome
Questions?