This product MH-M38 is a low-power bluetooth design, supports new bluetooth 4.2 transmission, two-channel stereo lossless playback, after the module is connected to bluetooth, it can quickly realize bluetooth wireless transmission, which is very convenient. In an open environment, the Bluetooth connection distance can reach 20 meters.
Widely used in various Bluetooth audio reception, various audio DIY modification, etc.
Function Description:
1. Bluetooth V4.2 version, support Bluetooth automatic connection technology, support WAV/WMA/FLAC/APE/MP3 lossless decoding, stereo binaural output.
2. After the module is powered on, the mobile phone searches for the Bluetooth name MH-M38, and the music can be played after connecting to the Bluetooth;
3. Module blue indicator:
When the Bluetooth is not connected, the indicator light flashes quickly;
When the bluetooth is connected, the indicator light is always on;
When Bluetooth is playing, the indicator light flashes slowly.
Pin Description:
5V: The positive pole of the power supply is 5V.
GND: negative power supply
VBAT: Lithium battery positive 3.7-4.2V
L+/L-: Left channel output (directly connected to the speaker).
R+/R-: Right channel output (directly connected to the speaker)
1. Power supply: You can directly use the MICRO USB Android cable 5V for power supply, or you can additionally connect to a 5V power supply or a 3.7V lithium battery. Note that the power supply interfaces of 5V and 3.7V are different, 5V is connected to 5V and GND, and the 3.7V lithium battery is connected to VBAT and GND.
The working current is 5V2A, it is recommended to use a 5V2A regulated power supply for better sound quality.
2. Support USB sound card, no driver (plug and play). Connect the module to the computer with a USB data cable, and the computer can play music through the amplifier output of the module
3. Audio output: Output left and right channel stereo audio signals, which can be connected to two speakers of 2-8 ohms and 3-5W respectively, and 4-ohm 5W speakers are used for storage.
4. This product has its own dual 5W power amplifier circuit, and must not be connected to another power amplifier for use! The outputs of the two power amplifiers cannot be connected in parallel or the negative electrodes can be connected together, otherwise the power amplifier chip will be damaged.
Precautions:
1. Signal interference: Bluetooth antennas are extremely susceptible to high-frequency or strong electromagnetic signal interference, and should be placed as far away as possible from wireless and other devices. And the board can not be next to the metal object, keep a certain distance.
2. If there is current sound when connected to the power amplifier board, the cause is the interference of the ground wire. It is recommended not to use the plug-in wire at the output end of the Bluetooth module. The wire must be welded, especially the ground wire to be welded, and the wire should not be too long, the shorter the better. , as thick as possible. The problem of the audio ground at the ground point of the power amplifier board must be connected to the ground of the audio input end of the power amplifier. This ground point can be welded in different positions to achieve the current sound. It is recommended to separate the power supply for the Bluetooth and the power amplifier board, and isolate the Bluetooth ground and the power amplifier ground.
3. Since this product is a bare board design, try not to touch the components on the board with your hands, it is easy to cause static electricity to kill the chip and cause it to burn.
