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aldinlapinig
Joined: 16 Dec 2005 Posts: 22
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EX_FREQC question.... |
Posted: Mon Aug 13, 2007 7:10 pm |
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I've looked at the EX_FREQC example of CCS C compiler but I couldn't understand what pin is used as input of the frequency being measured. Anybody knows this? Thank you. |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Mon Aug 13, 2007 7:34 pm |
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The comments say this:
Quote: | /// The input signal is to be supplied to pin C0 |
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aldinlapinig
Joined: 16 Dec 2005 Posts: 22
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Posted: Tue Aug 14, 2007 8:52 am |
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thank you PCM Programmer...I just couldn't understand how it configured pin C0 as output. I'm doing a project now that measures the frequency from 8 inputs. Can I use the same program to do this? How can I make the program to read the frequency from many different pins (like ports b4,b5,b6,b7, a1,a2,a3)? I'm sorry for asking too much but I'm running out of ideas. I'm an amature hobbyist. Thank you very much. |
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srikanth bodduna
Joined: 04 Jan 2009 Posts: 9 Location: India
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EX_FREQC.C with pic16f873a |
Posted: Sat Jan 10, 2009 1:49 am |
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did anybody tried the EX_FREQC.C with pic16f873a if so please help me...what changes sholud be made to get the result. |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Sat Jan 10, 2009 1:10 pm |
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Ex_Freqc.c uses Timer1 with an External Input. The input is on pin C0.
Pin C0 is a Schmitt Trigger input pin. This means it requires input voltage
levels of 0v to 4v, when the PIC is running at 5v.
Your circuit only provides 2.3v input levels. So it will not work.
You neeed to fix this problem. Increase the input level so it goes
between 0v and 4v.
Until you do this, nothing will work. |
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