Wiper Control with PDM

[incontrolsteve]

Hi all. I am trying to control a single speed (fast) wiper with PDM. I have viewed previous posts and modelled my control on DarrenR's system. It seems that the park signal is too short with the motor on fast, and the motor does not stop in time before the signal is false again, so I get just a short delay, before the motor starts again, so I can have either constant wipe with a short delay, even if I don't want it, or no wipe at all as I can't seem to create a "virtual" park that is triggered off the rising edge of the genuine park signal, that resets so I can have an intermittent wipe also. If anyone has any ideas how I can get around this I would be most interested.

[DarrenR]

Hi Steve,

Going back to the post I've made previously here, method 2 is what you need to use. It will work as long as the park signal is greater than 20mS long.
It doesn't matter how far past the park signal you go then, it will stop no matter what. In fact you could deliberately park the wiper at a time after the park switch if the switch was in the wrong position. You would have to move the set-reset operator into a condition instead of the motor output, and use the result of that condition to drive the output with a time delay when turning off, Set-Reset condition = true, false for 0.2s for example.
If you need more detail, please let me know.

Cheers,

[pcarroll]

if you make the input edge triggered it should work nomatter what.