General overview to help me understand.

kansaschuck

I'm having just a little trouble grasping some concepts.

I had an old Lynxmotion Robot. It had and mini sscii from SEE. I understand it runs Basic Stamp. Looking to upgrade and working on some new project and recycle some old.

So the robot moved via robomotion and servomotion software on my computer.

I download Parallax Basic Stamp editor and tried to load a few programs and it said 'no stamp found'. So now I'm beginning to understand that the SEE mini scci isn't full basic stamp and that the function supplied by basic stamp were being handled by the PC software Robomotion. (?)

My long term project is to write some code that drives servos via the PC and later a remote internet website. (standard click move device left/right)

So I need a servo set up that can be control by repeated commands thru a serial/usb port from the PC/Internet. (I've got the Internet to PC link covered).

I just don't understand the code/setup/functions/etc that are needed for a program to send multiple and continous commands to the servo. Can I package up a 'servo left' command and send it to the servo when needed? Must it always be the Parallax Editor? Can Perl initiate the transfer? What are the requirements for a software/command transfer to the Basic Stamp? For a command of such type to be understood by the servo does anther basic stamp program need a pre-loaded program?

To this end I've purchased the stamp II Parallax Servo Controller (USB) 28823 because I'll be working off my serial port-less Toshiba. Not very interested in VB but willing to listen.
Still interested in recycling the old mini sscii SEE but that's secondary. (ordered the Parallax USB to Serial (RS-232) Adapter with Cable) I've got lots of sevros. A couple min sscII. And www.parallax.com as needed.

Post Edited (kansaschuck) : 2/2/2008 6:15:26 PM GMT

Mike Green

What you have (SEE servo controller and Parallax Servo Controller) are not Stamps nor do they have much to do with Stamps other than they were originally intended to make controlling servos with a Stamp easier. They are simple microcontrollers that accept a serial character stream containing some servo control information and they produce control pulses for controlling standard servo motors.

If you download the documentation for the Parallax Servo Controller, particularly the non-USB one, you will find the descriptions of the serial character sequences needed. For example (from the documentation), if you sent an exclamation ("!") then the letters "SC", then a byte with the channel (servo) number from zero to 15, then a zero byte, then two bytes (least significant, most significant) with the binary value of the pulse width for the servo in 2us units, then a return character (binary value 13), the servo controller will send a stream of control pulses to the specified servo for the pulse width requested until told otherwise. Usually a value from 250 to 1250 will drive the servo through a 180 degree range of movement although the range of values and the range of movement can vary from servo to servo and from manufacturer to manufacturer.

Any PC or microcontroller can send these sequences and, with a PC, you could use any programming language that can send information out a serial port.

The SEE controller works in a similar fashion although using different serial control sequences. You'll have to look at the documentation for details.

kansaschuck

Thanks Mike,

That helps a lot to understand were I've been going wrong. Can you explain any more about 'send these sequences '? I assume I'd have to address the port, clear, open, close. Is there lots of programing invovled? Just need an little more understanding in that area.

If I could just get one good example of a couple of servo commands sent to Mini SSCII and the Parallax Servo board I think I'd could run from there.


Thanks

Post Edited (kansaschuck) : 2/2/2008 7:28:30 PM GMT

Mike Green

Get the documentation, read it, and look at the examples. They're written for the Stamp, but, if you send the same characters from a PC to the PSC, the PSC will do the same thing.

The most complicated part of the programming is getting the PC to open the serial port and, of course, figuring out what you want the servos to actually do.