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Need help on a 3Hz PWM

Summary: 7656 Views, 2 Replies, Latest reply by douglaslps on 20 Sep 2010 07:01 AM PST

douglaslps posted on 16 Sep 2010 11:06 AM PST
Member
2 Forum Posts

Hi guys,

this is my first post in this forum.

I have some C language experience and I'm facing some problems to configure a CY8C29666 chip to generate a 3Hz PWM pulse. The minimum frequency I was able to generate was 360Hz.

Can anyone walk me through that?

Thanks,

Douglas

Terrence posted on 17 Sep 2010 11:15 AM PST
Top Contributor
43 Forum Posts

Hi Douglas,

The CY8c29666 device is a PSoC 1 device, so your post belongs in the PSoC 1 forum.

Assuming a sysclock of 24Mhz, and a wanted PWM of 3Hz, would require a divisor of 24Mhz/3Hz = 8Mhz.

VC1 and VC2 can divide by 16 each, and VC3 by 256. So, 16x16x256 = 65536. (Hold that thought)

8Mhz/65536 = 122.0703125

So, using an 8bit PWM, with a period of 122 will give you the requested 3Hz output.

In Summary:

VC1 /16

VC2/16

VC3 source = VC2

VC3/256

----------------

PWM:

Clock = VC3

Period = 122

---------------

Hope this helps.

douglaslps posted on 20 Sep 2010 07:01 AM PST
Member
2 Forum Posts

Hi Terrence,

"The CY8c29666 device is a PSoC 1 device, so your post belongs in the PSoC 1 forum."

Also thanks for your help on 3Hz PWM. Another solution would be to use internal 32kHz as clock and use period as clock (32k) divided by 3, which results a period equals to 10666.

Regards,

Douglas