Dear Jamil,

Can timer 1 and CCP1 and CCP2 be used to control two
motors independently each with frequency range from
100Hz to 300Hz ? If Ok, how ?

Regards,
Samuel Lau

"Jamil J. Weatherbee" wrote:

> That shouldn't be too tough, but keep in mind the following:
>
> On the CW/CCW line you'll just toggle depending on the direction you want
> to go.
> The Pulse signal will be the tough part but at low frequencies like 100hz
> you can basically put the toggling of the line into the time interrupt
> routine, along with a counter to count how many pulses are remaining etc.
>
> Problem is the motor has some inertia and for smooth control you want to
> ramp the pulse frequency up at the beggining of the pulse train and down
> towards the end, so for this you can slow down the toggle rate, like once
> every 2 timer interrupts, once every 3,4,5, etc. interrupts.
>
> I have some drivers just like the ones you are describing except the
> selections for phase excitation are via dip switches.
>
> hope this helps
>
> On Wed, 19 May 1999, Lau Chi Cheung, Samuel wrote:
>
> > Dear Jamil,
> >
> > Thank you for your help !
> >
> > In my project, I used two bipolar stepping motors of 1.8deg/step.
> > Also, I used two drivers to drive these motors.
> >
> > Each driver has the following characteristics:
> > 1) 2 phase Excitation 1.8deg/step
> > 2) 1-2 phase Exciation 0.9deg/step
> > 3) Only 2 control signals needed to implement the control
> >      a) One is Pulse signal (control the velocity of the motor)
> >      b) Another is direction signal ( either High or Low for CW or CCW
> >          direction)
> > 4) For excitations in case 1) or 2), another control signal (High or Low)
> >     play the part.
> >
> > I want the program that can control the two motors independently and
> > each motor can run at  frequencies from 100Hz to 300Hz.
> >
> > Thanks,
> > Samuel Lau
> >
> > "Jamil J. Weatherbee" wrote:
> >
> > > Wait, I have dealt with "Stepper Drivers" and also directly interfacing to
> > > unipolar and bipolar stepper motors.  What is it exactly that you have and
> > > how is it labeled?
> > >
> > > On Wed, 19 May 1999, Lau Chi Cheung, Samuel wrote:
> > >
> > > > Hi, all
> > > >
> > > > I have used a PIC16C74 20MHz microcontroller to control
> > > > two stepping motors.
> > > >
> > > > Could you help me how to control these motors with 4 control
> > > > signals (two are for output pulses from 100Hz to 300Hz and
> > > > the other two signals are for direction control)
> > > >
> > > > Thanks,
> > > > Samuel Lau
> > > >
> >
> >