Well,

How the heck did you know it was a radio shack car???

Andy
----- Original Message -----
From: "Tom Handley" <thandley@TELEPORT.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Tuesday, November 07, 2000 11:30 AM
Subject: Re: [EE]: How to control a motor


>    Andy, I'm also hacking a Radio Shack R/C car to turn it into a robot.
The
> best way to control the motor is to use an H-Bridge. There are many
variants
> and several things to consider. The following links have a lot of info
> and/or links to other sites.
>
>       Portland Area Robotics Society. Links to many sites.
>       http://www.rdrop.com/~marvin/
>
>       Chuck McMannis. Good theory and both Bipolar and MOSFET H-Bridge
ckts.
>       http://professionals.com/~cmcmanis//robotics/servo.html
>
>       Bob Blick's site with a good Bipolar-based H-Bridge project.
>       http://www.bobblick.com/bob/projects/
>
>       Good theory with circuit examples of different types of h-Bridges.
>       http://www.cadvision.com/blanchas/hexfet/
>
>       James excellent Techref site with links and PIC code examples.
>       http://techref.massmind.org/
>
>    As far as my robot, I used a modified version of Chuck McMannis'
H-Bridge
> using N-Channel MOSFETs with built-in diodes (see link above). Since the
car
> has both 12V and 6V for the motor, I didn't have to hassle with a charge
> pump. It uses a quad opto-isolator controlled by a 16F876. I hacked the
> motor shaft to add a Hall-Effect sensor for a tach. So far it goes forward
> and backward with some intelligent (PID) control and has bumper switches
and
> an IR proximity detector. This is a spare-time project...
>
>    - Tom
>
> At 08:58 AM 11/7/00 -0500, Andy Kelley wrote:
> >Hello,
> >
> >I have an RC car that does not have a radio and i would like to make
> >it into a roving robot like thing.
> >
> >I am stuck with this:
> >how do I control a motor from a PIC using one side of the motor tied
> >to 1/2 rail(2.5v) and either grounding or connecting Vcc to the motor.
> >Now is the problem:
> >
> >I dont know how do this and I have already destroyed a few 2n222's
> >
> >the motor draws 6/10 of an amp.
> >
> >@ 2.5 volts that is 1.5 W.
> >
> >I tried a fet like this
> >
> > -/\/\/\/\- Gate
> >
> >
> >Source
> >__|_
> >/  /  /
> >
> >Drain - motor - 2.5v
> >
> >and all it did was make the motor spin in one direction.
> >
> >Also i have another motor i need to drive at full 5v so i need to
> >reverse both wires on the motor if i want to go in reverse
> >
> >How can i do this???
> >
> >Thanks
> >Andy N1YEW
>
>
> ------------------------------------------------------------------------
> Tom Handley
> New Age Communications
> Since '75 before "New Age" and no one around here is waiting for UFOs ;-)
>
> --
> http://www.piclist.com hint: To leave the PICList
> mailto:piclist-unsubscribe-request@mitvma.mit.edu
>
>
>
>
>

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu