360 likes | 432 Views
Critical Design Review - “Dayrider”. Team Dayrider George Jenny, Amjad Sawaged, Tim Ikenouye, Kieran Tie. Objectives. Minimum : A solar-powered, router-controlled RC vehicle Target : A self-controlled software-sensor interface with regenerative techniques for energy recapture measurements
E N D
Critical Design Review - “Dayrider” Team Dayrider George Jenny, Amjad Sawaged, Tim Ikenouye, Kieran Tie
Objectives • Minimum: A solar-powered, router-controlled RC vehicle • Target: A self-controlled software-sensor interface with regenerative techniques for energy recapture measurements • Optimal: A vehicle that combines efficient design, functional power management, and a dynamic user interface in an aesthetically pleasing package CDR - Team Dayrider
Status • Components selected and shipping • Preliminary wire-wrapping of modular pieces (ADCs) • Control software of the MSP430 I.P. • Schematics: main board, subsystems sketched out and transferring to Altium • Router hardware/software modifications completed CDR - Team Dayrider
Block Diagram CDR - Team Dayrider
Motor - Traxxas “Stinger 540” • 20-turn DC brushed motor • ~1.5A at 3V no load • ~33mA at 500 mV reverse • Already standard on the current chassis CDR - Team Dayrider
Battery – STAAB • 6V output • 3.4 Amp-hour capacity • 7-7.5 rated charging V • ~0.692 kg • 134mm/34mm/60mm CDR - Team Dayrider
Solar Panels • 7.2 V@200 mA • Thickness 0.6mm (24 mil) • Total Size 253mm x 150mm • Weight-25.9g CDR - Team Dayrider
Microcontroller - TI MSP430F1611 • 16 bit RISC CPU • 8 MHz operational frequency • 48 KB Flash, 10 KB Ram • 48 GPIO pins • Analog Comparator, DMA • Hardware Interface: • 2 UART or SPI for hardware Interface: (USART 0, USART1) • I2C mode for peripheral interface CDR - Team Dayrider
Microcontroller - TI MSP430F1611 CDR - Team Dayrider
Modular Peripherals • Hardware addressed on each peripheral board • Plug and Play onto main board • Modularized design allows for easier assembly and debugging • I2C Bus: supports 7 and 10 bit addressing modes (p308 user guide) CDR - Team Dayrider
I2C Bus • Basic implementation of I2C Bus • Must be implemented in USART0 CDR - Team Dayrider
USART0 Control Register RXDMAEN - Transmit data from I2C via DMA upon receiving data SYNC– (1) for [SPI or I2C] mode, (0) for UART mode I2C– (1)selects I2C mode when SYNC = 1 I2CEN– enables(0) or disables(1) operation of I2C mode MST– selects master (1) or slave (0) mode CDR - Team Dayrider
I2C Timing Diagrams One clock pulse is generated by the master device for each data bit transferred. The I2C module operates with byte data. Data is transferred most significant bit first as shown in Figure 15.3 STOP Condition: SDA Low to High while SCL is High START Condition: SDA High to Low while SCL is High Change of Data only allowed while SCL is Low, otherwise START and STOP conditions are generated CDR - Team Dayrider
I2C Addressing Scheme Start Condition Stop Condition Acknowledge bit sent by receiver after each byte Direction of data flow on SDA can be changed by master by issuing a repeated start condition: RESTART is issued, slave address issued with new value for R/W bit CDR - Team Dayrider
Motor Controller - LMD18200T • Controlled using PWM by additional MSP430F2003TN connected to I2C bus • Steering mechanism: 5 V supply servo motor, dead straight D = 50%, f = 392 Hz @ 1 V, modulating D from 40% – 60% steers left to right. Functional diagram CDR - Team Dayrider
Motor Controller Schematic 3 inputs to motor controller supplied by smaller MSP430F2003 CDR - Team Dayrider
Analog to Digital Converter - PCF8591 • Operating supply voltage 2.5 – 6 V • Serial throughput of data via I2C • 4 Analog input programmable with multiplexer • Addressing via 3 hardware addressing pins • Sampling rate given by I2C bus speed Programmable hardware bits CDR - Team Dayrider
ADC schematic • 4 input ports • I2C interface • 3 programmable hardware bits CDR - Team Dayrider
Light-to-Voltage Converters - TSL14S • Converts light intensity to output voltage • Single supply operation 2.7-5.5V • Connect to PCF8951 ADC • Mount along perimeter of car Output pulse falling edge Output pulse delay rising edge Output pulse fall time Output pulse rise time CDR - Team Dayrider
TSL14S LVC schematic • 4 LVC’s connected directly into ADC • We will have 2 of these modules for a total of 8 LVC’s CDR - Team Dayrider
Range Sensors - MaxSonar EZ1 • Analog 10mV/inch output • Detection from 0 – 255 inches (~20 ft.) • Single 5V power supply • Very low power; draws only 2mA • < ½ the size of other sensors in its class • Connect to PCF8951 ADC CDR - Team Dayrider
Range Sensor Schematic • All 3 sensors multiplexed in 1 ADC • Same ADC used throughout all peripheral modules CDR - Team Dayrider
Parts List • MSP430F1611 microcontroller • MSP430F2003 microcontroller • LMD18200T motor controller • PCF8591 ADC’s • TSL14S light to voltage converters • MaxSonar EZ1 range sensors • Sparkfun F1611 Dev board • Assembled chassis with motor • STAAB deep cycle battery (2) • Traxxas Stinger 540 motor • Solar Panels • Linux router • MAX233a level converters • HAC-UM96 wireless transceivers CDR - Team Dayrider
Serial Communication - MAX233e • Converts TTL/CMOS levels coming from router/microcontroller to RS232 levels for computer/HAC-UM96 • 2 needed - one for router, and one for microcontroller/UART CDR - Team Dayrider
Serial Communication - HAC-UM96 • 96kbps wireless transceivers • Transmission power 10mW • 433MHz frequency • Range 300-500m • Takes TTL or RS232 inputs - will use RS232 for ease of debugging CDR - Team Dayrider
Software - MSP430 • Written in C / Assembly • Developed using IAR Embedded Workbench • Tested on prototyping board from Olimex • Final version transferred to main circuit • No software yet, but… CDR - Team Dayrider
Software - MSP430 • Use Cases - Outline software algorithms for the operation of the vehicle • UC1 - Avoid Obstacle • UC2 - Drive to Sunlight • UC3 - Drive Vehicle • Test cases for all possible paths of use cases • Domain model under construction… CDR - Team Dayrider
Software - Linksys WRT54G • Linux - OpenWRT • lighttpd - web server • Ajax - live updating of site • PHP - system commands • Serial data processor CDR - Team Dayrider
Web Interface - Concept CDR - Team Dayrider
Web Interface - Demo CDR - Team Dayrider
Division of Labor • Software Kieran & Amjad • User’s Interface (webpage) • Autonomous Control • Peripherals • Hardware Tim & George • Wire-wrap board • Peripherals • Regenerative Braking CDR - Team Dayrider
Milestone 1: November 2 • Preliminary MSP430 code • Serial communication between vehicle and router • Moving Vehicle CDR - Team Dayrider
Milestone 2: November 30 • Completely Solar/Battery Powered • User control of Vehicle • Range Sensors CDR - Team Dayrider
Expo: December 14 • Energy Regeneration • Peak Power Tracking CDR - Team Dayrider
Schedule CDR - Team Dayrider
Questions? CDR - Team Dayrider