9.3.1 WPS Configuration Methods

There are two authentication methods that can be used with WPS:

1. PBC (push button) method – A physical button is pressed on the AP which puts the AP into WPS mode for a limited period of time. WPS is initiated on the ATWINC15x0 by calling m2m_wifi_wps with input parameter WPS_PBC_TRIGGER.
2. PIN method – The AP is always available for WPS initiation but requires proof that the user has knowledge of an 8-digit PIN, usually printed on the body of the AP. Since the WINC is often used in headless devices (no user interface), it is necessary to reverse this process and force the AP to use a PIN number provided with the WINC device. Some APs allow the PIN to be changed through configuration. WPS is initiated on the ATWINC15x0 by calling m2m_wifi_wps with input parameter WPS_PIN_TRIGGER. Given the difficulty of this approach, it is not recommend for most applications.

The flow of messages and actions for WPS operation is shown in the following figure.