Control Relay with Timer

Using Arduino Programming Questions
1

Hello,

I want to on relay with push-button and turn off after 15 min, during the 15 min timer if I push the button again realy will not off.

Best Regards,

2

detect a button press. look for a change from button not pressed to pressed. add a 10 msec delay to debounce after reading button state.

keep track of the relay "state". when button pressed and relay state FALSE, turn relay ON and capture time, msecLst = millis().

When button pressed and relay state ON, turn relay OFF and set state to FALSE.

while relay state is ON, check if current time, millis() - msecLst > 15 mins. when true, turn relay OFF

3

When button pressed and relay state ON, turn relay OFF and set state to FALSE.

OP actually wants the button ignored if the relay is on, I think:

during the 15 min timer if I push the button again realy will not off.

(In which case, do nothing.)