Editing Smart card (section)

=====Buttons=====

Depending on Complex Card types, buttons have been added to allow an easy interaction between the user and the card. Typically, these buttons are used to:
* Select one action, such as which account to obtain the balance, or the unit (''e.g.'' currency or number of trips) in which the information is displayed,
* Enter numeric data via the addition of a digital keypad,
* Enter text data via the addition of an alphanumeric keyboard.

While [[Membrane keyboard|separate keys]] have been used on prototypes in the early days, capacitive keyboards are the most popular solution now, thanks to technology developments by AudioSmartCard International SA.<ref>{{cite web |title=Infogreffe – AudioSmartCard International SA |url=https://www.infogreffe.com/entreprise-societe/391975125-audiosmartcard-international-sa-750196B12386.html |website=Infogreffe |publisher=French corporate register |access-date=12 June 2021 |archive-date=1 May 2021 |archive-url=https://web.archive.org/web/20210501035129/https://www.infogreffe.com/entreprise-societe/391975125-audiosmartcard-international-sa-750196B12386.html |url-status=live }}</ref>

The interaction with a capacitive keyboard requires constant power, therefore a battery and a mechanical button are required to activate the card.