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