LT ThomasTJ Volinski
Pat O’HaraKole Reece
MSP430 & Cortex Motor Driver
Design Team 6 2
Outline
• Background Information– DRV8824– MSP430– Stellaris (Cortex M3)– Software
• Proposed Solution• Budget
– Fabrication and Assembly
• Risk Analysis• Agenda2/16/2011
Design Team 6 3
Project Overview
• DRV8824EVM• Max Drive Current 1.6 A • Dual Motors Control• MSP430 and DRV8824 IC• Protective Features– Over Current– Short Circuit Protection– Temperature Protection
• Applications – ATM, Printers, – Handling Machines Video Security Cameras, Printers, Scanners
2/16/2011
Design Team 6 4
DRV8824
• H-Bridge Structure (Dual Bridges)• MOSFET Implementation• Pulse Width Modulated Current Regulation • Switching Frequency 500kHz• Problem Modularity. More Robust Design
Needed!
2/16/2011
Design Team 6 5
MSP430
• Mixed Signal 16-bit RISC MCU• Low cost, Low Power embedded
systems• 8MHz Clock• 55KB Flash• 5KB RAM• 5 Power Saving
Modes
2/16/2011
Design Team 6 6
MSP430
2/16/2011
Design Team 6 7
Stellaris(Cortex M3)
• ARM architecture allowsfor low power embeddedelectronics
• Thumb 2 instruction set• 32-bit RISC MCU• 80MHz Clock• 256KB Flash• 96KB SRAM
2/16/2011
Design Team 6 8
Software Background
• Code structured to enable any chip to be used• Uses RS232 standard to communicate with
microcontroller • PC connects to DIMM through USB• Sends signals such as direction, step, and mode
2/16/2011
Design Team 6 9
Proposed Solution
• Removal of MSP430F1612 and definition of DIMM ports
2/16/2011
Design Team 6 10
Proposed Solution
• Design of MSP430F1612 control card• Map pins between MSP430 and Cortex• Port MSP430 code to Cortex M3
2/16/2011
RS232 Analog PWM GPIB JTAG
Design Team 6 11
Budget
Expenses Cost
Parts (97) $55.97
PCB Fabrication (DRV) $345
PCB Fabrication (DIMM) $200
PCB Assembly $350
Total $950.97
2/16/2011
Design Team 6 12
Fabrication
• 4 - Layer Board– Top and Bottom Layer Traces– Ground Layer– Kelvin
• Drill holes, Contacts, and Labels• 4PCB Company Quote:
2/16/2011
Qty 1-day 2-day 3-day 4-day 5-day E Test(Lot)1 $1,845.44 $1,103.44 $891.44 $732.44 $573.44 $125.00 5 $382.89 $234.49 $192.09 $160.29 $128.49 $140.00
Design Team 6 13
Assembly
• Bill of Materials - $55.97 for DIMM and DRV• SSOP IC’s (Surface Mount) on DRV• LQFP IC on the DIMM• ECE Shop will assemble only as low as SSOP
• OneStopAssembly Quote:
2/16/2011
Qty 2 Day Labor Cost 5 Day Labor Cost 10 Day Labor Cost1 593.24 433.78 361.48
Design Team 6 14
Risk Analysis
2/16/2011
Risk Effect Level of Impact(1, 3, 6)
Likelihood(1, 3, 6) Score
Delayed PCB layout Design
Delayed PCB Fabrication 3 3 9
Delayed PCB Fabrication
Delayed code Debugging and
Testing6 1 6
Incorrect DRV8824 Design
Inability to control motor 6 3 18
Incorrect MSP430 DIMM Design
MSP430 DIMM rendered useless. Stellaris still valid.
3 3 9
Design Team 6 15
Agenda
2/16/2011
Task Deadline Completion
Send DRV to Fabricator3/1/2011 Completed
Send DIMM to Fabricator3/18/2011 40%
Stellaris Coding4/15/2011 5%
Test Stellaris
4/22/2011 0%
Design Team 6 16
Questions?
2/16/2011