W55AD808, a low cost 8-bit ADC with 8 input channels. Each channel can be defined as digital or analog input mode independently.  In analog input mode, this channel can accept an analog input range from 0V ~ V_REF and convert it into a 10-bit digital data format (with 8-bit significant digits) . W55AD808 provides a serial interface for host CPU to control it. Beside analog input mode, all input pins can be defined as digital input mode; host CPU can monitor them by the serial interface.