[PD] Please help with a patch i want to do

[Johannes Taelman]

On Mon, 24 Mar 2003, [iso-8859-1] arm pdlist wrote:

> I have a slider that outputs values from 0 to 100.
> Then, say from 0 to 20 i want to trigger file1.avi,
> from 21 to 40, trigger file2.avi, and so on. The
> problem is that whenever i change the slider within a
> certain range (say range from 0 to 20) the file is
> always being triggered. I want to trigger the file
> when the value of the slider is within a certain
> range, but the following values within that same range
> shouldn't trigger the file again. For example, when
> the value is 14 it would trigger the file for the
> first time, but if the following value is 15 i don't
> want to trigger the file again. I just want to triger
> a file when the first value of a certain range is
> received, the other following values of the same range
> shouldn't trigger that file again.

[---------|-------] (slider)
 |
[/ 20]
 |
[int]
 |
[change]
 |
[outlet]

If you need to deal with sensor data you probably want a hysteresis loop
around all transitions, cause the sensor output may fluctuate around a
threshold causing too many changes.

[---------|-------] (slider)
 |
[/ 20]
 |
 | [r hysteresis]
 | /
[+ ]
 |
[int]
 |
[change]
 |
[t f f]
 X       (crossed wires)
[- ]
 |\
 | [* .2]
 |  |
 | [s hysteresis]
 |
[outlet]


I hope my ascii art is readable...

 j#|@