PWM: how do I get the PWM line to go low when I stop ?

Started by armdeveloper June 6, 2007
I'm doing some DC motor control and using PWM to control the motor
speed. I only need to run the motor for 5 seconds at a time.

My PWM code works fine the first time I run it. The second time I run
it the PWM line goes high when I am done. I've tried everything I can
see in the PWM settings to have the line end low and I can't get it
to.

What am I missing ?

Thanks

An Engineer's Guide to the LPC2100 Series

I found the answer in section 2.1 of the PWM chapter in the manual.
======================================================1. All single edge controlled PWM outputs go high at the beginning of a
PWM cycle
unless their match value is equal to 0.
======================================================
On Wed, 2007-06-06 at 08:56 -0600, armdeveloper wrote:
> I'm doing some DC motor control and using PWM to control the motor
> speed. I only need to run the motor for 5 seconds at a time.
>
> My PWM code works fine the first time I run it. The second time I run
> it the PWM line goes high when I am done. I've tried everything I can
> see in the PWM settings to have the line end low and I can't get it
> to.
>
> What am I missing ?
>
> Thanks