> On Sun, Apr 18, 2004 at 02:34:08PM +0100, Matt Marsh wrote:
>
>>On Saturday 17 April 2004 21:49, Byron A Jeff wrote:
>>
>>>So now onto how to get it done. If you have a CCP
>>>(Capture/Compare/PWM) module it's your bestest friend for such a
>>>project. It'll measure the pulse widths for you, give you an
>>>interrupt when it's done capturing, and has programmable polarity
>>>and counting speed. It's literally set and forget.
>>
>>So, having had a couple of responses saying that CCP would be useful
>>for this, I thought I'd better do a bit of research into CCP (given
>>that I hadn't heard of it before). It certainly looks interesting,
>>although from Microchip's website I can only see it available on
>>some of the 18F* chips? Is that correct?
>
>
> Nope. Not even close. From a cursory look, the smallest cheapest chips with it
> is the 16F818 with a Digikey single chip price of $3.25 and the 16F628A
> weighing in at $3.05. That's about double the price of the 12F629. OTOH
> you do get more pins, more memory, and more peripherals to play with
> (like a hardware UART if you happen to need it).
>
>
>>If so, I might have to do
>>without CCP and do it the more manual approach as I was hoping to
>>do this on one of the small 8-pin 12F629 (or similar) chips.
>
>
> It's a tradoff. A more expensive 18 pin part that has the hardware vs. a
> less expensive 8 pin part that doesn't. Since I have stacks of both on hand
> (along with 16F87X and 18F parts) I'd just pick the one that the application
> requires. However as I said in my original post, there are no right or wrong
> choices here, just choices. So pick based on what you have on hand, or the
> price point, or if the design requires multiple tasks to be done at the same
> time (A big seller for me. It's why I choose hardware laden parts like the
> 16F88 and the 16F877A).
>
> The only wrong choice is something that doesn't work.
>
> BAJ
>
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