From: "Angel Caparr¢s" 
To: 
Reply-To: "Angel Caparr¢s" 


Is easier to program a microcontroller to drive a stepper motor in half
step mode than a DC servo. Servos have wider range of speed.but you will
have to deal with encoder feeback , and PID control.

It possible to program a Microcontroller to drive stepper in microstep
mode,directly generating PWM by sofware  or by hardware , some models has
built-in  PWM modules .

PIC micros are cheap , fast (RISC 20Mhz)and some free assemblers are
available,there are C Compilers most of them commercial or free with some
limitations.
Atmel devices  has very nice  microcontrollers too and their C compiler is free.
You can use power IC to drive steppers like L298N (2A high power bipolar
steppers),ULN2308(500ma unipolar),or L293(600mA with internal diode
Protection).

Web Astronomia
http://www.terra.es/personal9/angel.caparros




-----Mensaje original-----
De: owner-atm{at}shore.net [mailto:owner-atm{at}shore.net]En nombre de Stanislav Kogan
Enviado el: Domingo, 20 de Julio de 2003 11:02 p.m. Para: atm{at}shore.net
Asunto: Re: ATM DC motor control questions



Hello.

On Sat, 19 Jul 2003 21:50:24 -0700
"Bob May"  wrote:

>
> The PWM controller controlled from a microprocessor will keep the
> torque up will be the best thing.

Yeah, that's what I'm planning to use. However, I looked up on the net, and
the schematics I've seen usually use a potentiometer to control the speed.
Can you point me to an example circuit that uses a microcontroller? It
would really help me - I'm not very versed in electronics.

That raises another question: do you think it may be wise to switch from a
DC motor to a stepper motor? It would definitely be easier to control.

Best regards.
--

Stanislav Kogan

eMail: kogan_s{at}mail15.com

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