The redstone gate is a mechanism consisting of pistons set to different delays. Using what i call a duel-face delay switch, the pistons are able to have their own TURN ON time and their own TURN OFF time. In order to make a compact design for decision making, I use what I like to call a pulse separator, which allows buttons to be next to each other without combining signals and screwing up everything. When the OPEN button is pressed, a redstone signal activates the OPEN mechanism. The signal is then seized and the pistons retract. The CLOSE button then extends/retracts the second set of pistons (CLOSE mechanism) to shut the gate.