In some countries people need to use wifi in the coffee shop because it's so expensive to use the mobile connection so if the coffee shop owner use one password of wifi forever ,many users can connect without entering in coffe shop next days, for this reason he need to change the password everydays or maybe every some days so my product is a simple machine which can generate many random passwords by using a generate button(this button can be used only by the coffe shop owner ,so it's protected by padlock https://youtu.be/08uenbV__no ) and it contains another button to displaying the password for coffee shop customers.

To summarise the idea step by step :

1) The coffee shop owner press the generate button to generate a new password
2) This password will be used as a wifi password by entering in the WiFi password configuration in smartphone(192.168.1.1)
3) Then it can be displayed for customers when they press the display button