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Today's Experiment
Pic Pyro 12
NOPPP Software for 12F675
Pic Pyro 16
NOPPP Software for 16F877A
Pic Pyro 18
NOPPP Software for 18F452
1st Project
Hello World
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Microchip Technology, Inc.'s
PIC Microcontrollers
The RCA CDP1802 was a GREAT starting point in the world of
CPUs. It was static and could be clocked at super slow speeds so one could
actually whip out the logic probe and poke around for whatever the problem
might be. The PIC series of MCU's offered by Microchip offers this same
advantage. Development with the PIC seems light years ahead of the
CDP1802, mostly because of the software tools available for it. Never mind
the obvious fact that the CDP1802 predates the PIC series by a few
decades, but it also helps that the PIC is still in production. The
CDP1802 is out of production and getting hard to find.
Most peripheral glue is built in to the PIC, making it
literally a one-chip solution for many projects. Main program memory, data
memory, A/D modules, Timer modules, I2C Bus capability, USB Modules, and
so on make the PIC a great component to build your project around. There
is an enormous number of PIC part numbers to choose from, from entry-level
simple control units to massive 80-pin chips with every conceivable
capability.
PICs come in the form of IC's, 8-Pin DIPs on up. With
normal CPUs and logic, each specific pin on the IC represents a certain
function. For example, pin 1 on the 74LS04 is always the input pin for
inverter number 1. It cannot be changed. That's what pin 1 does. On the
PIC? Totally different. Each pin can be programmed to represent a certain
function during runtime. Want pin 1 to be an A/D input? OK. Want pin 1 to
be 9600 baud serial output? OK. Want pin 1 to directly drive an LED? Easy.
The best thing about this is that pin 1 can be all these things, within
the same program. How simple is working with the PIC? Simple! Except for
the quirky instruction set, working with the PIC is a dream. It's perfect
for experimenter's breadboarding. The only pins that are not programmable
are the power, reset, and clock pins.
The most popular PIC for beginners seems to be the 16F84A.
There may be better choices for your first PIC, but with the immense
amount of example code and projects built around this PIC, it is a good
choice. It can run at speeds from DC to 20MHz. It has 1K of nonvolatile
main memory. It is an 18-Pin DIP, 13 pins of which are programmable.
The only problem? The same one as always... lack of
memory. Sure, 1K of onboard memory on the 16F84A may be more than enough
for 99% of projects and experiments, but I want MORE! Like... 64K would be
nice. Sure, the 13-bit PC can only count to 8K but... well, one can dream. |