ECE 477 Senior Design ECE 477 Senior Design Group 12 Group 12 Spring 2006 Spring 2006

Daniel daSilva

AtandraBurman

Eric Aasen

HarshaVangapaty

OutlineOutline

• Project overviewProject overview

• Design challenges facedDesign challenges faced

• ECE 362 knowledge usedECE 362 knowledge used

Project OverviewProject Overview

Maximum Power Point Tracker (MPPT) :Maximum Power Point Tracker (MPPT) :

• DC to DC converter that converts the input voltage from a solar cell DC to DC converter that converts the input voltage from a solar cell array to the output voltage of a battery pack.array to the output voltage of a battery pack.

• Optimum “power point” along Optimum “power point” along current vs. voltage curve that current vs. voltage curve that produces power for solar array.produces power for solar array.

• Our tracking algorithm will provideOur tracking algorithm will providecontrol of the DC to DC converter bycontrol of the DC to DC converter byadjusting the duty cycle on the PWMadjusting the duty cycle on the PWMin order to achieve this power point. in order to achieve this power point.

• Relay data to the telemetry unit and driver interface system on the Relay data to the telemetry unit and driver interface system on the solar car via the CAN bus.solar car via the CAN bus.

Design Challenges FacedDesign Challenges Faced

• Board sizeBoard size– Board area must be no larger than 1.8” by 3.0”Board area must be no larger than 1.8” by 3.0”

• EfficiencyEfficiency– Car puts out a maximum of 1200W of powerCar puts out a maximum of 1200W of power

– Critical that most of this power is used for motion of the carCritical that most of this power is used for motion of the car

– 8 converters on the solar car, thus 1mW consumed by this tracker 8 converters on the solar car, thus 1mW consumed by this tracker equals 8 mW consumed on the carequals 8 mW consumed on the car

• High DC AccuracyHigh DC Accuracy– Critical for finding the maximum power point of the solar arrayCritical for finding the maximum power point of the solar array

– Critical for data as, solar array power output and converter Critical for data as, solar array power output and converter efficiency, gathered by vehicle’s telemetry system efficiency, gathered by vehicle’s telemetry system

ECE 362 Knowledge UsedECE 362 Knowledge Used

• Understanding and implementing ISA of a microcontrollerUnderstanding and implementing ISA of a microcontroller• Buffer I/O handlingBuffer I/O handling• Interrupt HandlingInterrupt Handling• Analog-to-Digital ConverterAnalog-to-Digital Converter

– Convert input voltage, current and temperatureConvert input voltage, current and temperature

• PWMPWM– Controls conversion ratio of DC-DC converter boardControls conversion ratio of DC-DC converter board

• SPISPI– Load the CAN address of the device, detect cables, send various Load the CAN address of the device, detect cables, send various

flags to diagnostic LEDsflags to diagnostic LEDs

Project DemoProject Demo

• Demo shown in conjunction with the other Demo shown in conjunction with the other two Solar teams.two Solar teams.

ECE 477 Senior Design ECE 477 Senior Design Group 13 Group 13 Spring 2006 Spring 2006

Matt Cozza, Joe Waugh, Evan Zelkowitz, Elmer Chao

OutlineOutline

• Project overviewProject overview

• Design challenges facedDesign challenges faced

• ECE 362 knowledge used ECE 362 knowledge used

• Project demoProject demo

Project OverviewProject OverviewOur team designed and created a telemetry Our team designed and created a telemetry

board for the Purdue Solar Racing teamboard for the Purdue Solar Racing team

• Interfaces with Motor Controller, Battery Interfaces with Motor Controller, Battery Pack, Packet Modem, PowerPoint trackers, Pack, Packet Modem, PowerPoint trackers, and Driver Interface System.and Driver Interface System.

• Gathers temperature, acceleration, and GPS Gathers temperature, acceleration, and GPS data.data.

• Transfers information out to Driver Interface Transfers information out to Driver Interface System and Packet Modem.System and Packet Modem.

Design Challenges FacedDesign Challenges Faced

• Integrating with motor controller, battery Integrating with motor controller, battery system, GPS module, driver interface system, GPS module, driver interface system, and power point trackerssystem, and power point trackers

• CAN protocol CAN protocol • PIC processor and compiler quirksPIC processor and compiler quirks

– Banked memoryBanked memory– Compiler “issues”Compiler “issues”

ECE 362 Knowledge UsedECE 362 Knowledge Used

• Register settingsRegister settings• Microcontroller SPI port operations and Microcontroller SPI port operations and

UARTUART• Timers and interruptsTimers and interrupts

Project DemoProject Demo

• Demo shown in conjunction with the other Demo shown in conjunction with the other two Solar teams.two Solar teams.

ECE 477 Senior Design ECE 477 Senior Design Group 14 Group 14 Spring 2006 Spring 2006

Jason, Nathanael, David, DavidJason, Nathanael, David, David

OutlineOutline

• Project overviewProject overview

• Design challenges facedDesign challenges faced

• ECE 362 knowledge used ECE 362 knowledge used

• Project demoProject demo

Project OverviewProject Overview

• Driver interface for Solar Racing TeamDriver interface for Solar Racing Team• Communication with onboard power trackers Communication with onboard power trackers

and telemetry board via CAN busand telemetry board via CAN bus• Allow driver to navigate through a text-based Allow driver to navigate through a text-based

interface to issue commands to the solar interface to issue commands to the solar battery chargers (power trackers)battery chargers (power trackers)

• Display speed, battery power, and other Display speed, battery power, and other information on the LCD information on the LCD

Design Challenges FacedDesign Challenges Faced

• Low Power RequirementsLow Power Requirements– Used high efficiency switching regulatorUsed high efficiency switching regulator

• OrCAD bug with overlapping nets on different layersOrCAD bug with overlapping nets on different layers

• I2C bus needs pull up resistorsI2C bus needs pull up resistors

• PLDs are smallPLDs are small– had to move functionality to microcontrollerhad to move functionality to microcontroller

Design Challenges FacedDesign Challenges Faced

• Component Datasheets (configuration/usage Component Datasheets (configuration/usage information buried deep)information buried deep)– Such as LCD requires few seconds to boot Such as LCD requires few seconds to boot

upup• Controlled Area Network (CAN) Controlled Area Network (CAN)

communication protocolcommunication protocol– Send/Receive CAN messagesSend/Receive CAN messages

• Useable Menu SystemUseable Menu System

ECE 362 Knowledge UsedECE 362 Knowledge Used

• Assembly Language (and embedded C)Assembly Language (and embedded C)• Software/Hardware Debug skillsSoftware/Hardware Debug skills• On-Chip PeripheralsOn-Chip Peripherals

– I2C serial interface (LCD communications)I2C serial interface (LCD communications)– A/D Module (Temperature and Diagnostics)A/D Module (Temperature and Diagnostics)– Timers (Timeouts, CAN interrupts)Timers (Timeouts, CAN interrupts)– SCI (RS232)SCI (RS232)– Software DebouncingSoftware Debouncing

Project DemoProject Demo

• LinkLink

Questions / DiscussionQuestions / Discussion