Picaxe

PIC microcontrollers




PIC microcontrollers come in a wide range of
packages from small chips with only 8 pins and 512
words of memory all the way up to very powerful
devices that have 32 Kilo words of memory and 84
pins to connect to electronic circuits
.



8 and 16 bit EEPROM/EPROM/ROM CMOS
Microcontroller



Applications in personal care, security systems,
remote transmitter/receivers




Programmable input/output terminations



This block diagram shows a PIC
microcontroller application in a vacuum
cleaner

http://www.microchip.com


Microchip’s Infrared products enable the
embedded system designer to easily add
infrared wireless connectivity


http://www.microchip.com



Internal view of a microcontroller


PIC development boards are used to program and
run simple programs



Serial PC interface to


program IC



Some small PICs though powerful have only 35
instructions that control its operation
.


PROGRAM DEVELOPMENT TOOLS



Icon Assembler (CoreChart) Simple Flowchart



Pin Description for PIC12C508A



GP0


Bi
-
directional I/O port/ serial programming data mode.


GP1


Bi
-
directional I/O port/ serial programming clock.


GP2/T0CKI


I/O Bi
-
directional I/O port. Can be configured as T0CKI.


GP3/MCLR/VPP


Input port/master clear (reset) input/programming voltage
input.


GP4/OSC2


I/O Bi
-
directional I/O port/oscillator crystal output.


GP5/OSC1/CLKIN


Bidirectional IO port/oscillator crystal input/external clock
source input


VDD
—

Positive supply for logic and I/O pins


VSS
—

Ground reference for logic and I/O pins


THE PICAXE MICRO CONTROLLER



The PICAXE is a low
-
cost ‘FLASH’ memory


based microcontroller.



These microcontrollers can be programmed


over and over again (typically 100 000 times).




The PICAXE uses a simple BASIC language (or graphical flowcharts).





It is much easier to learn and debug than industrial


programming languages.



PICAXE programming is at the ‘chip’ level.



The microcontroller is programmed via a 3
-
wire


connection to the computers serial port.


THE PICAXE MICRO CONTROLLER




Has an internal A to D converter enabling analogue


inputs with digital outputs.


THE PICAXE MICRO CONTROLLER