Classic Computer Magazine Archive ANTIC VOL. 3, NO. 12 / APRIL 1985


Latest robot-Atari interface news

by MICHAEL CIRAOLO, Antic Associate Editor

The day isn't here yet when your personal robot can perform most household chores and is the family's third major purchase after home and car. But it's not that far away, either.
  "Optimists say that in five to ten years a robot will meet you at the front door with the newspaper and a martini. It will cook dinner, teach the kids and keep grandmother company," according to Sharon Smith of RB Robot Corporation in Golden, Colorado.
  Smith's scenario covers personal robots, as opposed to the industrial robots that are already doing much of the detailed assembly of late-model automobiles and other technology-intensive products. Personal robots need to be both more mobile and less expensive than their builder industrial siblings. Voice control would also be a desirable feature in personal robots.
  "We're still in the first generation of personal robots," said Smith. This first generation includes both expensive robots and inexpensive remote-controlled machines that are closer to toys.

The typical first generation robot like the RB Corp.'s RB5X, or the Heath Company's HERO-1 kit costs about $1,500, looks like R2D2, can move around in a programmed pattern, sense walls, doors, people and other obstacles, and monitor its own energy level.
  RB5X and HERO-1 are both expandable. You can add, at substantial extra cost, extendable manipulator arms, voice synthesizers, and so on. But that still doesn't mean these robots can do anything as practical as walking your dog or answering the door.

RB5X is fully programmable from most computers, including the Atari. It has an RS232 port, through which you can download a program into RAM, or install a debugged program in EPROM form. RB5X, like other comparable robots, has its own internal language. But it accepts downloaded programs in assembly and Tiny BASIC.
  Tiny BASIC can be programmed on the Atari and other microcomputers using a text editor. It is a compact form of BASIC that supports only integers and has no strings. A command to go RIGHT FORWARD would read as @#7802=#08.
  Other, cheaper, robots are remote-control toys directed through the Atari's joystick port. The Think Tank ($100, 3R Robotics, Houston, Texas), connects your Atari to a radio-control module so you can use the joystick or keyboard commands to direct a model tank.

"The cost of personal robots will go up as robots are able to do more things," Smith predicted. 'There's a balance between cost and what the robot can do. Right now, robots are a little expensive for what they actually do."
  Meantime, robot companies are looking to the second generation of personal robots. "The second generation will include programmable vacuuming and home security," Smith said. These robots won't be able to move furniture, but they could sense and steer around obstacles as they vacuum on a programmed route.
  Second generation robots could also be responsible for home security-they could sense intruders and other hazards, and notify the police, fire department, or paramedics.
  First and second generation robots both depend on three separate but interactive technologies.
  The robot must have sensors, usually sonar, touch-sensors or infrared. The robot must also have a way of physically affecting its environment, such as wheels for mobility or manipulator arms. And the robot must have computing power.

As the robot craze continues to catch on, there is more information available for hobbyists who want to make their own robots.
  The Robotics Society of America offers tips on finding inexpensive supplies, news of industrial robot developments, a calendar of events and a hefty schedule of seminars on robot-related subjects. (Their address is 200 California Avenue, Suite 215, Palo Alto, CA 94306.)
  Antic carried specific instructions for a basic robot project in December 1983, January 1984 and June 1984.
  Making your own Atari-controlled robot is not that difficult or expensive if you are a hobbyist at heart and somewhat mechanically inclined.
  Let's say you wanted to start with a simple robotic arm with one joint. Movement of the joint would be concoupled to a gear train and electronics that convert logic-level signals into power to drive the motor. The actual arm can be made from an Erector set, wood, metal or any material you can work easily.
  Instructions for the arm come from your Atari via the joystick port, so you would need a DB-9 connector and some cable wire.
  A simple BASIC program would open the joystick port and send the appropriate pulses. If you wanted to extend the robot arm, you'd turn on the servo, and send it pulsed messages for as long as you wanted it to continue extending.

After you've produced remote-controlled motion, you can think about the next step. Each joystick port contains four pins which can be set for input or output. On the Atari 800, with four ports, you can have sixteen lines, or 65,536 external operations (that's 2 to the 16th power).
  With so many lines to the outside world, you can direct multiple motors-arms, wheels, perhaps a rotating head. Your Atari can also accept sensor input, which can be used to keep the robot from running into things.
  On the other hand, requiring your Atari to recognize objects is not possible. This requires more computing power than a small computer has, and would also require highly sophisticated sensor equipment.
  Many hobbyists use sonar on their robots, according to Tom Burke, who builds and services robots for U.C. Berkeley's Lawrence Hall of Science.  Until a few years ago, sonar was very expensive. But with the advent of Polaroid's sonar-using autofocus cameras, the technology became small and cheap enough for hobbyist.
  Evaluation kits for the Polaroid sonar system are available for around $100, said Burke. These kits can be interfaced to an Atari. The sonar has a range between one and 39 feet, and a resolution of one inch. Of course, the further from the source, the less the accuracy.
  Inexpensive Radio Shack infrared LEDs and phototransistors, of the same wavelength, can be wired into a circuit that will follow a line on the floor, according to Burke. The photo-transistor will measure the difference between light and dark, keeping the robot on a track over a one-color painted line.
  Of course, these are not the only avenues open to the would-be robotics hobbyist. Jim Strope, head of the Robotics Society of America's San Franscisco chapter, suggested using the Atari's parallel bus to directly control a robot. Each line out of the bus could be amplified until it was capable of controlling a DC motor. (This issue of Antic contains the last installment of Earl Rice's four-part series explaining how to build Input/Output connectors for the parallel bus.)
  Strope said that many hobbyists are using a round robot platform with two unidirectional casters and two bi-directional wheels, all arranged in a square. If one wheel is on and the other off, the platform rotates. If both are moving constantly, the robot moves foward, etc.
  And so the robot revolution rolls on. It is a young field, with plenty of room for you and your Atari.