Microcontrollers you should know about

1
Microcontrollers you should know about

• Thomas Edwards
• http//www.t11s.com

2
What is a Microcontroller (uC)?

• A computer-on-a-chip
• Simple but reliable way to control
  electromechanical systems
• No boot-up / no hard drives
• Smaller than a PC
• Less power/heat than a PC
• Cheaper than a PC

3
What can you do with a uC?

• Flash LEDs in a particular way
• Move a motor in a pre-programmed fashion
• Have LEDs, motors, servos respond to switch or
  sensor inputs
• Connect devices to the Internet
• Much more!

4
What does a uC need?

• Power Supply the right voltage
• Support circuitry different needs for different
  uCs
• Voltage regulators
• Crystals or resonators
• Serial, USB, or Ethernet interfaces
• Programmer (usually PC based)
• Proto-board to assemble circuitry on

5
Basic Stamps

• Very popular!
• Runs PBASIC interpreter
• No Analog inputs
• BS2 (49)
• 4,000 instructions per sec.
• 16 Digital I/O pins
• 32 bytes RAM
• 500 instructions
• http//www.parallax.com

6
Other Types of Stamp

• BS Rev. Dx (34)
• BS1 w. proto area
• 16 bytes ram
• 80 instructions
• 2,000 instructions./s
• BS1 USB (39)
• 39.95
• BS2px (79)
• 38 bytes RAM
• 4,000 instructions
• 19,000 instructions/s

7
Programming BS in PBASIC

• For b2 0 to 5
• high 1
• pause 100
• low 1
• pause 100
• next b2

N VAR BYTE TOP FOR N 0 TO 100 SEROUT 16, 84,
10, "N ", DEC N, CR PAUSE 500 NEXT GOTO
TOP
8
Parallax Sensors

• Sensors made with the BS in mind
• But you could use them with other uCs

9
Basic Stamp Pros/Cons

• Cons
• Expensive
• Small memories
• No A/D inputs

• Pros
• Popular
• Easy to use
• Tons of online documentation
• Many sensors available

10
Fish Pain Maquette

• Basic Stamp reads button, drives fish animation
• Winbond Chipcoder voice board

11
Microchip PIC

• Array of cheap but powerful microcontrollers
• 1-10
• Natively programmed in assembly language
• Lots of functionality (A/D, PWM, timers, counters)

12
Some (of the hundreds) of PICs

• PIC12C508/509 (Small 8-pin package, internal
  oscillator, popular in small designs such as the
  iPod remote)
• PIC12F629/675/683
• PIC16F84 (generally considered obsolete, but
  still popular)
• PIC16F84A (upgrade to above, some versions do 20
  MHz, 11 compatible with PIC16F84)
• PIC16F628 (replaces the PIC16F84. The 16F628A has
  more program memory and fully compatible)
• PIC16F88 (an excellent all-round 18-pin PICmicro)
  
• The PIC16F87X family (The PIC16F84's "big
  brothers", with lots of built in hardware similar
  to the 16F88. Quite common in hobby projects.)
• PIC16F877 (RS232, Parallel Port Interface, PWM
  and much more)
• PIC18F452
• PIC18F4550 and relatives (Full-speed USB support,
  all sorts of inbuilt hardware. Very powerful and
  versatile)

13
PIC Assembly Language

• Harvard Architecture
• Separate instructions and data
• Memory Banks
• Many, many special registers for config

14
PIC C

• void serTxIsr(void)
• if (idxTxbufPut ! idxTxbufGet)
• TXREG txBufidxTxbufGet
• idxTxbufGet (idxTxbufGet)
  SER_TXBUF_MASK
• else
• PIE1_TXIE 0 //Disable USART Transmit
  interrupt when nothing more to TX

15
PICs Pin Overloading

• Pins can serve four or more different functions
• Flexibility to meet project needs with minimal
  pins
• Often difficult to properly configure

16
Sycophant

• Head mounted on R/C car chassis
• Follows viewers as they move down hall
• Sharp active IR sensors
• PIC 16F648A controller
• L293 Motor controller
• Windbond Chipcorder audio chip

17
Atmel AVR

• Family of microcontrollers
• ATmega
• ATtiny
• 1-15
• Similar to PIC, but slightly easier to program in
  assembly language
• Religious discussions about PIC versus AVR

18
Training Boards

• PIC18F458 training board (44.90
  http//www.futurlec.com/PIC18F458Training.shtml)
• ATMega163 training board (44.90
  http//www.futurlec.com/ATMegaTraining.shtml )

19
PIC/AVR Pros/Cons

• Cons
• Tough to program in assembler/C
• Programmer board required (sometimes 50)
• Many different types of PIC, programs dont port
  between them

• Pros
• Very cheap
• Many interfaces and functions (A/D, PWM, timers,
  counters, I2C)
• Lots of online documentation support

20
CUBLOC CB220

• Basic Stamp pin compatible
• But much more powerful
• 80 KB flash instruction memory
• 4 KB EEPROM
• 2 KB Data RAM
• 36,000 instructions per second
• A/D (up to 5V)
• Built-in 5V regulator
• Based on AVR
• CB220 34, Proto board 5
• http//www.comfiletech.com

21
CUBLOC BASIC

• Dim f_pos_1 As Byte
• Dim f_pres_1 As Byte
• Input 5 'P0 / Pin 5 as Input
• Opencom 0,9600,3,32,32 'open RS-232 channel to
  Xport
• Opencom 1,9600,3,32,32 'open serial channel to
  Servo Controller
• Bclr 1,1 'clear channel 1 tx buffer
• On timer(10) Gosub a2d 'every 100 ms
• On Recv0 Gosub servo_move 'on UDP in from
  Xport
• Do
• Loop
• a2d
• f_pres_1Adin(0)gtgt2 'scale 0-1023 to 0-255
• Put 0,f_pres_1,1 'send finger pressure to
  Xport
• Return

22
Lantronix Xport

• Ethernet-to-serial converter
• Can operate in TCP or UDP modes
• Web-based configuration
• Comfile dongle allows easy DB9 attachement
• Xport (54), dongle (8)
• http//www.comfiletech.com

23
CUBLOC Pros/Cons

• Cons
• More expensive than PIC/AVR, but less than BS
• Not very popular yet

• Pros
• Easy to program/use
• Many interfaces (A/D, PWM, I2C)
• Great vendor documentaton

24
Touch Maquette

• To touch someone over the Internet
• R/C servo driving plastic finger
• Force-sensitive resistor on tip
• CUBLOC 220, Xport, Pololu Serial Servo controller

25
MAKE Magazine Controller

• Just came out (149 for board)
• 30 I/O lines
• 8 A/D (up to 3.3V)
• 8 high current motor driver outs
• Ethernet/USB/I2C
• Atmel AT91SAM7X256 based / 48 MIPS
• C programmed
• Connect to Max/MSP via Open Sound Control (OSC)
• http//www.makingthings.com/makecontrollerkit/

26
The Alternative PC Parallel Ports

• 12 digital outputs
• 5 digital inputs
• 8 grounds
• Data pins (Dx) may also be inputs in
  bi-directional ports, giving 13 inputs

data _inp(atoi(888)) / read port 0x378 data
pins / _outp(atoi(888),atoi(data)) / write
port 0x378 data pins /
http//www.logix4u.net/parallelport1.htm
27
PC w. Serial/USB Interfaces

• The Serializer (139.95)
• 16 Digital I/Os
• 5 Analog inputs
• 2 x 4A DC motor drivers
• 2 RC Servo controllers
• I2C Interface
• .NET/C programmable
• http//www.roboticsconnection.com/catalog/item/176
  7486/2337356.htm

28
Microcontrollers you should know about

• Thomas Edwards
• http//www.t11s.com