Make ground signal last longer?
You can use RC-circuit with logic elements: short "0" impulse should charge some capacitor then while this capacitor did not disharged to "zero" logic level, you should invert it's logical voltage.







simulate this circuit &ndash; Schematic created using CircuitLab

The greather R3 resistance is, the longer delay you'll get. V2 is logic-levelvoltage source.