Subject:
|
Re: about robots and handy board
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Wed, 12 Apr 2000 02:16:18 GMT
|
Original-From:
|
FTHOMPSON9@AOLspamcake.COM
|
Viewed:
|
1011 times
|
| |
|
|
Dear Francois A du Toit:
PIC stands for Programmable Integrated Circuit. Generally it is what we
call a microcontroller. You write a program in Assembler, burn that program
into the PICs EPROM or EEPROM. Then when you put the PIC in its circuit, it
runs the program. Most of the pins on the PIC are inputs or outputs. (Which
they are, is determined by the program you write, and can be changed mid
program.) The pins which are not I/O are power, ground, reset, and two pins
for the crystal oscillator circuit. To a small extent a chip with power
applied and a crystal attached is like a Handy Board. Both expect the
external world to supply electrical input, and both using a program apply an
electrical output to the world in response to the input signals. There I
would say the similarity stops. The could be thought of as a
Microcontroller, but in the Handy board, it is really being used as a
microprocessor. The program that you write for the Handy board is stored on
a memory chip outside the 6811. The signals from the 6811 are conditioned on
the Handy board to be more useful to simple robots. With a PIC the program
is burned into ROM and will not go away until it is physically erased with UV
light or special voltages. The Handy board will loose the program when power
is removed (it's not as easy as it sounds), or when you tell the Handy board
to forget (unload) the program.
The primary advantage to the Handy board is that it is easy to use. You
write the programs in C in an interactive environment directly connected to
the Handy board itself. Finding program errors is easy. For small robots
nearly no electrical conditioning of the signal is required.
The primary advantage to the PIC is that it is cheap. You would use a
PIC processor if you plan to make a dozen or more identical robots. Signal
conditioning is almost certainly required. Finding program errors is
anywhere from nontrivial to very difficult.
When I was in St. Louis, I build a line following robot based on stepper
motors (to demonstrate stepper control to the club [MARS]) and a PIC
microcontroller. It took me more than two months to build, program, and fix.
It finally did make it all the way around a simple line course, but at a
very slow speed. Rick Moll snapped together a line follower over a weekend
using the Handy board and modified servo motors. It followed the line quite
well at a speed that put my stepper motors to shame.
If you are trying to learn about robots, get the Handy board!
You can learn everything you need to know about PICs (except what is
available in Senix parts) at their web page.
http://www.microchip.com/
For more info. on the Handy board try:
http://lcs.www.media.mit.edu/groups/el/projects/handy-board/index.html
Hope this helps,
Pherd
Currently Pensacola, FL
|
|
Message has 1 Reply:
 | | Re: about robots and handy board
|
| Francis, Thanks for the info! I'm not an expert, but doesn't PIC stand for "Peripheral Interface Controller"? Well, I guess it's all just semantics, they both could be correct... Just wondering, John Wynne (...) (25 years ago, 12-Apr-00, to lugnet.robotics.handyboard)
|
2 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
