Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

VHDL timer

hi, how can I write a program for a timer which Measures a pulse width that represents of range.i'm using un ultrasonic sensor, The distance can be calculated using the scale factor of 147u...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I also would like to add a note.

This simple scheme will not work if your sensor output has glitches.

If the pulse is like this:

.........|*|..|****************|

.........|.|..|................|

**********.****................|*********

you risk to measure the initial glitch and get wrong results.

In this case you need a more complex circuit or some other control signal.