You may need to reset your EZ-B v4 to switch Wi-Fi modes quickly, or if you forget the Wi-Fi password. Pressing the EZ-B v4 reset button with a pin or paper clip while the power is on will reset the Wi-Fi configuration to factory defaults. The factory default Wi-Fi connection is Access Point Mode. More details on the various connection modes can be found here.
There is a similar button on the IoTiny, next to the status LED. Simply press the button to reset the IoTiny.