Bluetooth Stereo Audio Receiver Module 1. Uses the KTC2700H Bluetooth module (BES2700H Bluetooth chip). 2. The pin holes have a standard spacing of 2.54 mm, which is convenient for soldering and debugging! 3. The board has integrated LED1 indicators! 4. Integrated power-on delay circuit; can be used after power-on! 5. The supply voltage is 3.3 V – 5 V; the voltage must not exceed 6 V! 6. When SPDIF output is used, DATA is the SPDIF OUT output pin! 7. Board size: 24 x 36.5 mm. Buttons: PI00: short press to pause, 3 seconds to start pairing, 5 seconds to clear the pairing record [PLAY] PIO1: short press to decrease volume [VOL-] PIO2: short press to increase volume [VOL+] PI03: short press to play previous song [PREV] PI04: short press to play song [INEXT] PI05: Bluetooth connection at high level (high-level output 3.3V). Bluetooth name: KTC2700H 1. Power-on method: Upon power-on, the device automatically establishes a connection, and if the connection fails, pairing mode is automatically activated. 2. Button PI00: short press to pause, 3 seconds to pair, 5 seconds to clear the pairing record. Pin Definition: 1: DATA: IIS Data Output 2: BCK: IIS Serial Clock 3: LRCILK: IIS Clock 4: -IN: 5V Power Input, Ground 6: SPK-R+: Differential Analog Signal Output 7: SPKR-: Differential Analog Signal Output 8: SPK-L+: Differential Analog Signal Output 9: SPK-L-: Differential Analog Signal Output 10: SPK-EN: Amplifier Enable, pulls up when audio is present 11: NEXT: Next Song Button 12: PREV: Previous Song Button 13: VOL+: Volume Up Button 14: VOL-: Volume Up Button 15: PLAY: Play/Pause Button 16: 33-0UT: 3.3V Output, used for the button's common pin 17: LED1: Blue Light 18: Red Light Black. Material: PCB. Package contents: 1 * Audio module. Only the above package contents are included; other products are not included. Note: Light reflections and different displays may cause the color of the item in the picture to be slightly different from the actual color. The allowable measurement error is +/- 1-3 cm.