Caption 1, DAC audio output, you need an external amplifier, and WT588D module is set to DAC output mode; 2, PWM audio output, direct drive speakers, WT588D module needs to be set to PWM output mode; 3, online download output line interface; 4. Reset button (when there is disconnected, or an error in the connection process, as well as the download is complete, you can click here to reset button); 5, the test button, ten keys K1, K2, K3, K4, K5, K6, K7, K8, K9, K10 respectively control ports P00, P01, P02, P03, P04, P05, P06, P07, P10, P11; 6, locking the seat can be placed WT588D module, WT588D external SPI-Flash (need to be converted Block), by the end of placement. 7, the control port pinout. 8, BUSY busy signal indicator 9, the power indicator 10, DC9V power input 11, USB cable input slot (large), connected to a computer via a USB cable, after turning on the power supply by USB.