Transcript Microcontrollers and DSPs

Resources:
Hardware and Software
Senior Design – Spring 2012
Microcontrollers
 Useful for analog-digital
conversions, timing, counting
pulses, serial communications,
PWM, digital I/O, and much more!
 Code can be interrupt driven
 Possible applications
 Perform an A-D conversion on a
signal and send that data to a PC
 Control an LCD display
 Receive information from a RF ID
reader
 Interpret signals from a numeric
keypad
*Pictures from http://www.electronic-kits-and-projects.com
Tips for using Micros
 Program in C
 Read all the documentation for the part!!!!
 Code in small steps
 Best first step is to make an LED blink
 Refer to code examples for help
 For digital I/O
 Be sure voltages are within permissible range
 Check if microcontroller can sink or source enough
current
 Development boards are a great way to get your
hardware running fast!
TI MSP430
 Ultra low power Micro
 Free samples from TI (we have a university agreement
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and can get samples and programmers)
Free IDE based on eclipse with integrated debugging
Free GCC compiler
Many RTOS solutions available
Hardware debugging makes finding problems in code
easier
Some development boards have integrated wireless
ZigBee support ez430-R2500
Many Examples
Very easy to use USB programmers/Debuggers
*Picture from http://www.ti.com/
ATMEL ATMEGA Microcontrollers
 Many Different microcontrollers – most
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commonly used for projects are
MEGA168/MEGA128
Powerful user community = Arduino project
Many open source tools, hardware and libraries,
entire tool chain runs on Linux/Windows/Mac
Several simple serial boot loaders to load
programs, programmers are easy to build
Software USB support
More limited hardware debugging
*Picture from http://www.atmel.com/
Arduino
Open source microcontroller
Arduino UNO available in the
ECE store
Based on ATMEL processor
IDE based on the
Processing language
Small boards are easy to
use but have limited I/0
Larger boards have more I/0
but are costly
*Pictures from arduino.cc
Microchip PICs
 Available in lab: PIC16F887
 Many other types available to order
 Two excellent resources
 PIC data sheet
 PICC Compiler Help
 Receive two PICs for free
 Disadvantage: Closed
compiler/toolchain
*Picture from http://ww1.microchip.com/downloads/en/DeviceDoc/39582b.pdf
Other Microcontrollers
 BASIC Stamp
 Programmed using BASIC
 Can be used when high performance is not
necessary
 ARM (LPC, TI, etc)
 Very Advanced toolchain, very powerful
microcontrollers with a lot of features
 Hard to program the hardware
 Cypress PSoC
 GUI based programming software
 Development Kits Available
*Pictures from http://www.basicx.com/ and http://www.ti.com/
DSPs
 TI TMS320C54x
 Same DSPs as used in ECE 420
 Programmable in assembly Simulink or C
 Useful for audio processing
 TI TMS320C6713
 Floating point DSP
 Useful for image and video processing
NATIONAL INSTRUMENTS CVS
Real time vision processing
system
programmed in Labview
*Images from http://www.ni.com/vision/cvs.htm
FPGAs
 We have several new NI FPGA boards
 Useful when very high speed calculations
are needed
 Power hungry
 Consider using a microcontroller first
 Great for projects which require a lot of
recursive or parallel calculations
XBee Radios
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Low-power wireless sensor networks
Zigbee/IEEE 802.15.4 compliant
ISM 2.4 GHz wireless
Serial interface (9600 to 115200)
10 uA sleep current
100 feet indoor range (may vary)
Advanced features include toggling pins
on remote radio, Over the air
programming of features, and many
integrated functions in the radio
hardware (Series 2)
Other Radio Chips
 Lynx
 Simple wireless data
transmitters and receivers
 Available in lab
 Wifi and Bluetooth
 Serial interface to
microcontrollers
 One starting point for products
www.sparkfun.com
* Pictures from http://www.linxtechnologies.com/ and www.sparkfun.com
Miscellaneous Parts
 Large selection of components in the
lab
 Check the inventory on the website or
speak with your TA
 NI myDAQ
 12V SLA batteries
 Various motors
 GPS receivers
 LCDs
 Resistors, Capacitors, Inductors,
diodes, transistors, etc.
Board Layout Software
 Eagle
 Installed on lab computers
 Free download for board
size < 4x3in x 2 layer
 Tutorial on class drive
 Orcad
 Installed on lab computers
 More complicated, lots of
options
* Picture from Kieran Levin
SENSORS!
Interface between:
Real World
Temperature
Humidity
Proximity
Light
Acceleration
Switches
Etc.
Your Circuit
Solutions
Limited Inputs
Limited input ranges
Limited bandwidth
Limited accuracy
Amplification
Clamping within a voltage
range to avoid damage
Debouncing
Filtering
Current to voltage
conversion
Etc.
SENSOR CHALLENGES:
Challenge
Potential Approaches
Inadequate voltage / current
Op Amp, buffer, transistors
Noise
Hardware or software filtering
Switch Bouncing
S/R Latch
Capture Signal
Sample & Hold
Limited Sampling Rate
New sensor
DATASHEETS!
Find them from manufacture or supplier websites.
Without a datasheet it is hard to design around an unknown part
Some Good places to look
Datasheet Repositories
• www.alldatasheet.com