Rod Barman rodb at
Fri May 6 14:46:38 GMT 1994

Well, since you asked ... 


This short document is an introduction to the Mini Board.  This
information is posted to the Internet newsgroup "comp.robotics"
periodically or upon request, or may be mailed to individuals who
specifically requested information.  This document may be distributed
without restriction.

The Mini Board is a miniature microprocessor-based controller board
designed for control of small robotic devices.  It may be used for any
number of applications that require sensing with analog and digital
electronic sensors and/or control of DC and stepper motors.  It may
programmed to operate "stand-alone" (i.e, running a program
autonomously from its internal memory) or attached via an RS-232
serial line to provide sensing and control capability to a desktop

The Mini Board was designed at the MIT Media Laboratory.  The printed
circuit board design, electronic schematic, related software, and
documentation are are copyrighted but may be distributed and used
freely.  This means that you may use the Mini Board for any
application you like without having to pay anyone for its design, but
you must leave the copyright information intact if you re-distribute
boards and/or plans.

The remainder of this note provides the following additional

1.  An introduction to the Mini Board:  its functionality, hardware
design, and available software.

2.  How to obtain documentation, software, and printed circuit board
artwork for the Mini Board.

3.  How to obtain physical boards, parts kits, and assembled boards.

4.  How to join the "robot-board" mailing list, which is formed
largely of Mini Board users.

For more information, please contact Fred Martin at
fredm at 


A miniature controller board for small mobile robots

The MINI BOARD 2.0 is a complete embedded computer board for robotic
applications.  It can directly power four DC motors and receive inputs
from numerous sensors.  Its miniature size (smaller than a business
card) makes it suited well for mobile applications as well as other
embedded control.

It can be programmed in 6811 assembler code or C for stand-alone
operation, or it can serve as a serial-line based controller operated
by a desktop computer.

  * overall dimensions: 3.3" by 1.86", smaller than a business card.
    If desired, an off-board serial connector can be used, allowing an
    additional .6" of board length can be chopped off. 

  * nearly all parts can be purchased from Digikey (including all
    connectors and switches).  Extensive use of resistor packs 
    minimizes component count.

  * uses Motorola 68hc811e2 microprocessor with 2048 bytes of
    internal, electrically erasable PROM and 256 bytes of RAM.

  * four motor drivers for bidirectional control of small DC motors
    (up to 600 mA current, 36 volts each motor).

  * eight analog inputs; eight digital inputs or outputs; several
    timer and counter I/O pins, all broken out to convenient header

  * on-board 5v regulator allows board to be powered by any DC power
    source from 5.6 to 36 volts.

  * RS-232 compatible RJ-11 port for communication/program download
    between host computer.

  * two modular high speed serial jacks, allowing networks of multiple
    MB 2.0's to be constructed using common 4-wire phone cable.
    Multiple-mastering bus protocols supported.

  * optional battery level monitoring using voltage divider from
    supply voltage before regulation.

  * XIRQ line broken out to a pad:  when this line is given 12.5v,
    an 'hc711e9 chip with 12K of EPROM can be programmed in place.

  * MS-DOS, Macintosh, and Unix software provided for downloading
    programs to board.  6811 monitor program provided for recording
    changes in sensor state, controlling motors and interacting with
    other board features over serial line.

  * C/assembler libraries provided for code development using
    Dunfield Development Systems' Micro-C compiler, and ImageCraft's
    freeware icc11 C compiler.


Full documentation for the Mini Board is available via anonymous FTP
to "" (Internet  Go to
"pub/miniboard" directory and begin by reading the README file located
there.  ** You will need a PostScript printer to print out the
documentation files; the main document is about 60 pages long. **  If
you do not have ready access to a PostScript printer, you may order a
hard copy by sending a check or money order for $5 (U.S. dollars) made
out to "MIT Epistemology and Learning" at:

	Epistemology and Learning Publications
	M.I.T. Media Laboratory
	20 Ames Street Room E15-315
	Cambridge, MA 02139 

Request the "Mini Board 2.0 Technical Reference."  International
orders are accepted without any surcharge; you just have to obtain a
check payable in U.S. currency.

Software for the MS-DOS, Macintosh, and Unix platforms is also
provided on the FTP server.  The provided software includes a 6811
assembler and a program for downloading assembled programs to the Mini
Board.  ImageCraft's icc11 C compiler for MS-DOS is also available
from the MIT FTP site.  If you are interested in using the Micro-C
environment, you must buy Micro-C from Dunfield Development Systems
(which has no affiliation with MIT).  Information on doing this
accompanies the Mini Board documentation.

Printed circuit board artwork files, produced by Douglas Electronic's
"Professional Layout" program for the Macintosh, are on-line the FTP
server.  For more information about using this format, see the
information on the server.  Gerber-format files are also available on
the FTP server.

People who don't have access to anonymous FTP can do FTP-by-mail,
provided as a public service by DEC.  Send a message containing the
single word "help" to "ftpmail at" for instructions.  You
probably will want to start your queries by retrieving the file named
"allfiles.ftp", which is at the top-level directory of our FTP server.
This file is a recursive directory listing of all files on the server.


Two individuals are independent suppliers of Mini Board technology:

* Gregory Ratcliff (gratclif at, 1763 Hess
  Boulevard, Columbus, Ohio 43212; (614) 487-0694 (late evenings EST). 

  Greg sells blank boards for $6, parts kits, and assembled boards.
  Please contact him for information.

* Mark Reeves (mdreeves at, 1117 Braemar Court, Cary, NC
  27511; BBS and voice (919) 481-3170 (voice hours from 5-7 pm EST).

  Mark sells blank boards for $4.75, a variety of parts kits, and
  assembled boards.  See the file pub/miniboard/mb-kits.txt on the
  cherupakha FTP server or contact Mark directly for more info. 

  Mark is a supplier of the recent board revision called the "Mini
  Board 2.0 Extended."  This version of the Mini Board includes a
  power switch and DC power jack for ease of use.  Please see the file
  pub/miniboard/mbextend.txt for more information.


Greg Kulosa has established a mailing list for users of the Mini Board
and other robot controller boards.  

To join the list, send an e-mail message with the Subject: line
containing the following text:

	subscribe robot-board <your real name>

to "listserv at".  Then you will be automatically added to the
list.  To send a message to the people on the list, write e-mail to
"robot-board at".

Please *DO NOT* send administrative things to the main "robot-board"
mailing list address, as then everyone will get annoyed.  If you have
trouble, you can contact Greg directly at "gkulosa at".

   -----------------------end of document--------------------------
-----------------last updated Tue Mar 22 16:15:35 1994-----------------

Rod Barman, IRIS NCE @ Laboratory for Computational Intelligence, 
University of British Columbia
rodb at

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