AL5181 Switch Version Characteristic: 1. Analog, I2S, SPDIF signals can be switched and output freely 2. With control functions such as volume, up and down songs, play/pause, etc 3. Onboard ceramic antenna, accessible for over 10 meters, and supports external antennas 4. Receiver board size: length x width 5.5cm X4.1cm 5. Support AUX analog signal input function 6. Supports USB Audio 7. Supports USB power supply or external 5V power supply 8. Bluetooth name AL5181 1. P103- Volume Up, Next Song Function A 10K resistor and a tactile switch need to be connected in series to the board at+3.3V0UT Short press a song, long press to increase volume 2. PI02- Volume reduction, previous song function A 10K resistor and a tactile switch need to be connected in series to the board at+3.3V0UT Short press the previous song, long press to decrease the volume 3. AUXR - External audio source right channel input 4. AUXL - External audio source left channel input 5. SPD1F - Coaxial/Fiber Optic Output End 6. LED - External LED access terminal, this pin is connected to the negative terminal of the light-emitting diode and the positive terminal is connected to 3.3V 7.+3.3V_0UT -+3.3V power output 8.+5V-5V power input, choose one from two options of USB power supply 9. MCLK-I2S master clock signal frequency=256 x LRCK 10. CLK-I2S serial clock signal frequency=2 x LRCK x32 11. LRCK-12S frame clock signal, adaptive frequency 12. DATA-I2S serial data output 13.0UTL - Analog signal left channel output 14.0UTR - Analog signal right channel output 15. GND - Ground