Microcontroller recommendation?

[Greg Brandon]

I am trying to choose a microcontroller for use in a robot.
I am not overly familiar with electronics, and although I can read a
schematic, my skills WRT a soldering iron and breadboard are nil.

Here are what I need, as far as I understand -- and I have several
questions.
(I am considering Zilog's Z8-Encore!)

- on-chip program/data memory (the Encore has up to 64K)
- ability to control at least 4 servo motors
- something with readily available software development tools (ie.
cheap or free C compiler)
- easy to program, preferably via a serial cable.

here are some of my concerns:

I'm sure I could accomplish all of this with the Z8-Encore's development
kit, but then when it comes to putting something on a board small enough
for my robot, and without the LED panels, etc. that the test-board has,
I wouldn't know how to set up the circuitry. Is this something simple, or
no?

How would I interface the microcontroller with a GPS module, such as
motorola's M12+ chip, or their InstantGPS chip?

Can anyone recommend anything? I've looked at the 6.270 robot board, the
Handyboard, and the miniboard (68hc11-based boards) developed by MIT. They
could be options -- especialy the miniboard due to it's small size, but if I
recall correctly, it could only handle two servos.

Any other suggestions?

Thanks.

 

[Sergio Masci]

I am trying to choose a microcontroller for use in a robot.
I am not overly familiar with electronics, and although I can read a
schematic, my skills WRT a soldering iron and breadboard are nil.

Here are what I need, as far as I understand -- and I have several
questions.
(I am considering Zilog's Z8-Encore!)

- on-chip program/data memory (the Encore has up to 64K)
- ability to control at least 4 servo motors
- something with readily available software development tools (ie.
cheap or free C compiler)
- easy to program, preferably via a serial cable.

here are some of my concerns:

I'm sure I could accomplish all of this with the Z8-Encore's development
kit, but then when it comes to putting something on a board small enough
for my robot, and without the LED panels, etc. that the test-board has,
I wouldn't know how to set up the circuitry. Is this something simple, or
no?

How would I interface the microcontroller with a GPS module, such as
motorola's M12+ chip, or their InstantGPS chip?

Can anyone recommend anything? I've looked at the 6.270 robot board, the
Handyboard, and the miniboard (68hc11-based boards) developed by MIT. They
could be options -- especialy the miniboard due to it's small size, but if I
recall correctly, it could only handle two servos.

Any other suggestions?

Thanks.

You could use a dirt cheap 16F628 (about 2 USD) to control upto 12 RC
servos. It is an 18 pin device with its own internal 4MHz oscillator,
hardware USART and 2K words of program memory. The 16F88 is bigger and
better (8MHz internal oscillator, USART, I2C, ADC, and 4K words program
memory) but still a small 18 pin device. The 16F876 is a 28 pin device but
needs an external oscillator (similar to the 88 but with 8K words of program
memory).

The LITE version (free for non-commercial use) of the XCSB compiler (v0.19.0
due out in a few days) comes with a servo library that you can use to
program the above mentioned PICs. The LITE version is limited to 4 servos
and no library source while the commercial version is unrestricted and comes
with source.

A demo (code + circuit diagram) will also be available at
http://xcprod.com/titan/XCSB/CONTRIB/
that allows you to control 4 servos using a 16F628 (internal 4MHz
oscillator), 3 push buttons and an LCD.


Regards
Sergio Masci

 

[happyhobit]

Hi Greg,

How are your programming skills, ‘C’ and assembly? Do you understand
microcontroller architecture?

Buy a plug in breadboard, handy for learning more electronics and developing
your ideas. Buy some kits and learn to solder. You can build a programmer
for it for 4 bucks. A development / application board for about the same
( including microcontroller), but you have to know how to solder.

I like the AVR line of microcomputers. It will do everything you want, but
you have to know how to ask it. http://www.atmel.com/products/AVR/

Check out AVR Freaks, everything about AVR microcontrollers.
http://www.avrfreaks.net/index.php

Check out the ‘Butterfly’ development board. Develop your application here
with a display and canned routines, then port it to a 2 Sq. In. application
board in your robot.
http://www.avrfreaks.net/Tools/showtools.php?ToolID=462

Intelligent modules, like GPS, normally communicate serially. (1 bit at a
time) Go online and get their datasheets (PDF).

I did a Google for AVR + robot + servo, and got over 1000 matches. "Google
is your friend".

Jay