It is great to have the watering happen on schedule, but sometimes you will want to manually operate the sprinklers, even if to test that the hardware works properly.
This Sprinkler Control project step adds a manual override: The TPS2L(G2) has a four-key keycap. The application displays "ON" over the first key (F2) and "OFF" over the fourth key (F4). Pressing the "ON" key turns the relay on, and the "WATERING (MANUAL)" message is shown on the screen. Pressing the "OFF" key turns the relay off.
The response to key presses is implemented through the On Keypad Pressed event block (the corresponding key is selected in the block's properties).
There is also the On Keypad Released event block.
Explore how this application implements overrides. This is done correctly: Once you have enabled the sprinklers manually, the end of scheduled watering will not turn the relay off. This logic is implemented through the manual_override variable.