Can anyone think of how to detect a TTL 1 microsecond pulse using just a PIC? I'm not measuring the width - just the rising edge. I dont think I can do it using a 16f616. I'm afraid I'll have to use a 555 timer to do this but dont want to yet.
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Can anyone think of how to detect a TTL 1 microsecond pulse using just a PIC? I'm not measuring the width - just the rising edge. I dont think I can do it using a 16f616. I'm afraid I'll have to use a 555 timer to do this but dont want to yet.
I've never worked with that part number, but it should have an INT or INT0 function. Somewhere (INTCON is where I find it on the PICs I play with) there is a bit to determine if you get an Interrupt on Rising or Falling Edge. On that old of a chip, the pin will probably be specific and non-transferable (ala PPS).
Yes, the datasheet specifies INT pin input high or low time: Minium 25ns so should be no problem with 1us. Question then becomes how much latency you can accept, how fast do you need to "react" on that pulse? Either you'll setup an actual interrupt OR you simply poll the interrupt flag.
/Henrik.