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Using the Propeller as a Clock Source — Parallax Forums

Using the Propeller as a Clock Source

rjo__rjo__ Posts: 2,114
in Propeller 1
Some CMOS chip cameras require an external clock source.  They nearly all accept a 24MHz, 50%duty cycle clock.  The Propeller handles this very nicely.
In the data sheets of some cameras as the clock frequency changes from 24MHz(in either direction) the duty cycle also has to change. 

Can the Propeller generate a variable duty cycle for frequencies in the range of 8-80Mhz? 

Comments

  • rjo__rjo__ Posts: 2,114
    I don't know how that happened...now what do I do?
  • jmgjmg Posts: 15,145
    edited 2015-07-17 03:54
    How much does the duty cycle change ?The Prop has some flexibility, but it will always quantize to 12.5ns


  • rjo__rjo__ Posts: 2,114
    Depends on the camera... and I don't remember where I ran into the issue... from memory I want to say it goes up to about 70percent in both directions.... going up less duty, going down in frequency more duty... could be the other way around.  That's for a constant voltage of course.  My reasoning is that by varying the voltage and frequency I could get around the issue... but then everything blew up and I'm sitting here, twiddling my thumbs:)
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