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From: ear@usfirst.usfirst.org (Eric A. Rasmussen)
Subject: Re: Joystick control of Robot
Message-ID: <DAJwIE.7Fr@mv.mv.com>
Nntp-Posting-Host: usfirst.mv.com
Sender: usenet@mv.mv.com (System Administrator)
Organization: U.S. FIRST
Date: Thu, 22 Jun 1995 01:37:24 GMT
References: <3rtv8t$jgg@elaine47.stanford.edu>
Lines: 26

In article <3rtv8t$jgg@elaine47.stanford.edu>,
Patrick Hugh Campbell <patrickc@leland.Stanford.EDU> wrote:
>I am using an analog joystick (from my 486) to control my mobile robot for
>Robot Wars.  I am reading the analog signals for X and Y with my micro-
>controller board's 8 bit A/D.  My robot has 2 motors (left & right) which
>are PWM'd for speed control.  I was wondering what's the best way to
>transform the X & Y signal to the % power & direction signals to my motors.

A very simple possibility that I haven't seen mentioned yet is to simply get
two joysticks and only use the Y axis on each one.  By mounting them side by
side, you get the same intuitive control layout as the old Atari Battlezone
machines, and direct mapping of input channels to output channels.  (You
could also do full power turns in place without coming up with a funky
non-linear algorithm.)

FYI, your control system sounds very similar to control system used for the
1995 U.S. FIRST Competition.  Our transmitter and receiver are HC11 based,
with two joystick ports plus some extra switch inputs on the transmitter, and
PWM outputs (8 channels) on the receiver.

I'm curious as to what you use for an RF link.  We use pairs of wireless
RS232 modems.  Perhaps if we found a cheaper RF link, we could market the
systems to Robot Wars competitors or other R/C "Robot" enthusiasts.

--------------------< Eric Rasmussen - ear@usfirst.mv.com >---------------------
U.S. FIRST=U.S. Foundation for Inspiration & Recognition of Science & Technology
