Pls don't use 5 V ,it will destory our module directly ,maybe when you use for a while.the main chip of WTV020-SD module maximum voltage is 3.6V,so work voltage can not beyond 3.6V.
Did work. It was my fault. I forget to read the manual and connect to 5v the Shutdown pin. Works like a charm. Now, I will write a library to control the volume. Keep you posted guys.
In order to reduce power consumption while not in use, the PAM8803 contains shutdown circuitry that is used to turn off the amplifier's biascircuitry. This shutdown feature turns the amplifier off when logic low is placed on the SHDN pin. By switching the SHDN pin connected to GND,the PAM8803 supply current draw will be minimized in idle mode. The SHDN pin cannot be left floating due to the pull-down internal.