Presentation | Power supply | Infra-red radar | Motor drivers | CPU |
PC Interface | PC Software | Frame
Italian documentation

Likeness a N.A.S.A. project, Stream was born. Stream is a six wheels robot, remote controlled by PC.
I built it likeness the rover Sojourner, sent to Mars by the N.A.S.A in the July 1997.
In the September 1997 I started this project, completed in the February 1999, when Stream moved its first meters.
I bring it at my graduate examination on June/July 1999 (Italian school), get through with the votation of 100/100 (Electronic and Telecommunication course).

How does it work?
Stream can execute 4 movements: go ahead, go back, turn on the left and on the right.
It's very friendly to use: with its administration program that I developed you can send to it the route.
The lastest version of this software is Stream 4.0, written in C++, available only for Windows (when I developed it I didn't still know Linux) in Italian language.
It works very simply: you must only complete a form with the way that you prefer, then send the data using a dedicate command.
You can write your own way choosing by 4 movement: "Avanti" (go ahead), "Indietro" (go back), "Destra" (turn on the right) or "Sinistra" (left). You must also specify a quantity from 1 to 31, as centimeters for go ahead and back movement, or as 6° each one for the turns movement.
A fifth instruction is available: it's "Stop", to stop the robot.

How much is accurate covering the way?
Stream is very accurate: the error is less than 1% on the total. This is possible because I use step motors, making the system more complicated but obtaining a lot of advantages.
During the turn movement the rotation center is the center of the robot: so you can know always what is the exact position of Stream in the space.

Stream has a battery: how is its autonomy?
The medium electrical input is about 0,9A. Its battery is a rechargeable Pb 12V-2Ah battery. So it's autonomy is about 2 hours.

Stream has a radar. Why?
To dodge round obstacles, Stream has a infra-red radar. It can get objects far at least 15cm (depending on their reflecting ratio): when Stream "see" an object, it stop itself immediately. Then you can study a route to avoid the obstacle.

Stream receive the route from a PC. How can you do it?
You can link Stream to a PC by two ways: by cable or by radio connection. My model works only by cable, but there is a slot where you can put a radio-receiver module. There is another slot onto the PC interface, for the radio-transmiter module. How you can see in the picture Stream already has an aerial, essential for a radio comunication.

You must connect an interface board to the PC. How can you do it and why?
You must connect an interface board on the COMx port of your PC. This module reads data from the serial port and send them by radio signals (using the radio-transmiter module) or by cable (you must connect this board and Stream with a cable) to the robot. External supply is not needed: this module take current from the PC, because it use only 3mA, from 20mA available from the COMx port.
This circuit convert data from serial standard to Stream protocol.

Where the Stream admin software works?
Stream 4.0 needs of Windows 95/98/NT o.s. and more or less 100KB of available disk-space. Of course you need the serial port to connect the interface board.

How can Stream execute your commands?
Stream has an ST62T10 microcontroller, built by SGS-Thomson. It contains also the software to receive data from PC, drive motors and so on..

How do you can use Stream?
Stream has infinite applications. You can adapt Stream as you need, building hardware parts and developing software to drive them.
You can patch the software adding new commands as you need, for example to drive a mechanic arm or to return to the PC result of a relevation (temperature, humidity...)
An example: if you need to get the temperature from an inaccessible spot, you can put a temperature sensor on a mechanic arm, so Stream go there for you. Then it returns to you the results.
But remember that to return the data you must implement a duplex comunication.

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