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Hey All

I'm using the MC9S12NE64, I've written a simple code so that when a
switch is pressed it will turn a motor on for 1/2 second. I'm using
the 3.3v from the NE64 to power everything.

When testing with a LED everything works as it should. The light
switched on for 1/2 seconds. But when I replace it with the motor
nothing happens.

Can someone please help me and tell me why the motor isn't switching
on.

Thanks
Gavin



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Gavin,

How much current does your motor draw? The 9S12 is limited in what it
can supply.

Digital logic chips like the 9S12 are also kind of fragile compared
to the rough world of motors (even small motors). It's a good idea
to use a transistor or some kind of drive chip to control the motor,
giving the expensive HC12 a layer of protection.

Stephen

--
Stephen Trier
Technical Development Lab
Cleveland FES Center
s...@po.cwru.edu



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Gavin,

If there is no sign of life in the motor, the problem is probably that the
motor draws more current than the driver or the power supply can deliver.

If the motor turns a little and then things stop, the problem is likely
that the high frequency noise from the motor brushes is causing the MCU to
operate incorrectly.

Can you tell us more about type of the motor and its specifications?

Can you outline the motor drive circuit, and the power supply arrangements?

This will help in suggesting the causes of your problems.

Steve Russell
Nohau Emulators
At 10:58 AM 4/28/2006, "Gavin" wrote:
>Hey All
>
>I'm using the MC9S12NE64, I've written a simple code so that when a
>switch is pressed it will turn a motor on for 1/2 second. I'm using
>the 3.3v from the NE64 to power everything.
>
>When testing with a LED everything works as it should. The light
>switched on for 1/2 seconds. But when I replace it with the motor
>nothing happens.
>
>Can someone please help me and tell me why the motor isn't switching
>on.
>
>Thanks
>Gavin
>

______________________________
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