In the A320, what action or control input triggers the activation of the ground spoilers?

In the A320, spoilers play a crucial role in various phases of flight, including takeoff, landing, and in-flight speed control. The aircraft is equipped with five spoiler surfaces on the wings, each serving specific functions. Spoiler number 1 functions as a ground spoiler, extending only when the aircraft is on the ground. Spoilers 2, 3, … Continue reading In the A320, what action or control input triggers the activation of the ground spoilers?