DPRG
DPRG List  



[DPRG] can i use a bulb mounted on an object for identification?

Subject: [DPRG] can i use a bulb mounted on an object for identification?
From: Sluggy slugmusk at home.com
Date: Thu May 18 10:25:16 CDT 2000

LO VENG CHEONG wrote:

>   Another problem met is that two motors rotate on different speed even
> giving the same PWM signal. So, it can't go straight. Then, I tried to
> tune the motors by adjusting the power level using the PWM technique. And,
> it can roughly go straight now. I know that it is not a good method. I
> should use the shaft encoder. 

You are likely to find, even with shaft encoders, that the motors will
actually need to run at different speeds. Not only will the motors run
slightly different speeds on their own, the wheels are unlikely to be
identical, even if you put them on a lathe and cutting them to size
(though that will help).

The big advantage of the shaft encoders that that you will be able to
know the angular position of the wheels at any moment. With one known
quantity, it will help you deal with the the inconsistencies.

> And i think that i may try to hack the shaft
> encoders from a mouse. As some of you taught me that I can hack the wheels
> and the light emitter and receivers but I don't know how I can interface
> theses to the i/o ports of my controller board and what is the operation
> of the receivers?

I have been intrigued by the concept of hacking a mouse for wheel
feedback. Long ago, I looked into this a little and I think that it's
doable. It would take some careful analysis of the output of a mouse
under such conditions, but there seems no reason why one could not
update positional registers from the encoders, one for each wheel.

You might be able to find some mouse programming info online somewhere
and modify that as needed.

Sluggy!

-- 
------

Why Windows NT Server 4.0 continues to exist in the enterprise
would be a topic appropriate for an investigative report in the
field of psychology or marketing, not an article on information
technology.  - John Kirch     http://www.unix-vs-nt.org/kirch/


More information about the DPRG mailing list