New to Servo Control

Hi all.
I don’t have much experience with electronics/robotics, and I’m trying to become familiar with a Pololu Micro Serial Servo Controller for a school project where I want to be able to control a number of servos.

I have the controller hooked up to a serial port (RS-232) and a simple servo, but I’m having some trouble sending commands to the serial port and getting the servo to respond. The servo moves once when plugged in.

I’ve been trying to send it commands from Hyperterminal. The green light on the controller blinks whenever I type into Hyperterminal but I don’t understand how to make something happen.

What would a typical command line look like? Should everything be in hexadecimal? Or can the controller understand decimal? Is Hyperterminal a good program to explore or are there other better options?

Thanks!
Emily

Hello,

Hyperterm is not a good option since it sends characters rather than just the raw numerical value that you want. For instance, “35” would get sent as the character ‘3’ followed by the character ‘5’; what you need is to send a single byte with the value of 35.

Most servo controller users don’t use a terminal program; instead, they write a custom program to make the servos do what they require. If you have access to visual basic 6, the following example could be helpful:

http://gpsbots.com/tutorials/vb/pololu_controller.php

Microsoft also has free versions of their developer tools that can be used to write applications that send data to the serial port:

http://msdn.microsoft.com/vstudio/express/

If you just want to do some initial tests with the servo controller, you can look for a terminal program that lets you send arbitrary bytes to the serial port or use a demo version of a servo controller program such as:

http://www.brookshiresoftware.com/vsa_downloads.htm

- Jan