keypad input for pin number
- keypad is sending after every press one number to a mqtt keypad topic
- numbers are stored in list
- only numbers between 1 and 9 are possible
- after 5 inputs the list is sent to a mqtt pin topic 4a. after the next input the first entry is deleted and the number is stored last and again the pin is send again to the second topic 4b. after 10 seconds the list is cleared and the process begins again