Bluetooth audio receiver module MH-M18 lossless car speaker circuit board
Module
Bluetooth Audio Receiver Module
MH-M18
Reference price
| 1: | $6.50 |
| 25: | $6.40 |
| 100: | $6.30 |
| 500: | $6.20 |
| 1000: | $6.10 |
| 5000: | $6.00 |
Product Information
Bluetooth audio receiver module MH-M18 lossless car speaker circuit board
Model Number：M2021030
Function
After the module is powered on, the mobile phone searches for the Bluetooth name mh-m18 / mh-m28 / mh-m38. After connecting Bluetooth, you can play music. Module blue indicator: when Bluetooth is not connected, the indicator flashes quickly; When Bluetooth is connected, the indicator is always on; When Bluetooth is playing, the indicator flashes slowly
Parameters
Built in lithium battery power supply: √, volume memory / adjustment; √, mute interface: √, key expansion: √, Bluetooth version: Bluetooth chv4.2, supporting Bluetooth protocols: hfpv1.7, a2dpv1.2, avrcpv1.5, avctpv1.2, avdtpv1.2, format support: supporting wav / wma / FLAC / APE / MP3 lossless decoding, stereo dual channel output, working voltage: 5v3.7v-4.2v, unconnected broadcast status: 5.5ma, connected working status: 20mA, deep sleep 3ua, Transmission distance: 20m, working temperature: – 40 ℃ – + 85 ℃, sensitivity: – 87dbm
The module interface adopts half hole process, and customers can directly patch or weld it on the board
1- Key: key control terminal (4 key functions, additional resistance is required), 2-mute: mute control terminal (high level 3.3V is output during mute and low level is output during playback), 3-vcc: positive 5V of power supply (short circuit diode is required for lithium battery 3.7V power supply), 4-gnd: negative pole of power supply, 5-l: left channel output, 6-r: right channel output
Volume power off hold
The default output is 100% volume. Press the key to control the volume increase and decrease. If the control volume is less than 15%, the volume output will be 15% after power on again; If the control volume is greater than 15%, keep the original volume unchanged after power on again.
Mute mute control terminal
It is used to control the power amplifier board. Mute outputs high level 3.3V and plays low level. The power amplifier board can be connected directly if it is silent and effective at high level. If the mute of the power amplifier board is controlled by low level, the reverse circuit needs to be added.
Key key control
This function can only be realized by connecting another resistor and key. Power supply: 5V power supply is used by default. If you need to use 3.7V lithium battery for power supply, you need to replace the diode with 0 Ω resistance of 0603, or directly short circuit both ends of the pad. The default delivery is 5V power supply. If customers need 3.7V lithium battery power supply, they can be customized
Tip
1.Signal interference: the Bluetooth antenna is easy to be interfered by high-frequency or strong electromagnetic signals. Try to put it away from the wireless transmission equipment, and the board should not be close to metal objects. Keep a certain distance. 2. If there is current sound on the power amplifier board, it is caused by ground wire interference. It is recommended not to use plug-in wire at the output end of Bluetooth module. The wire must be welded, especially the ground wire. Moreover, the wire should not be too long, the shorter the better, and thicker as possible. The audio ground is grounded on the power amplifier board and must be connected to the ground at the audio input end of the power amplifier. This grounding point can be welded at different positions to achieve the lowest current sound. It is recommended that Bluetooth and power amplifier board be powered separately to isolate Bluetooth ground and power amplifier ground. 3. Since this product is designed as a bare board, try not to touch the components on the board with your hands, which is easy to cause static electricity and burn the chip. 4. The Bluetooth audio module has very high requirements for power supply and will improve the quality of audio. It is recommended to add LC filter circuit, especially switching power supply, such as mobile phone charger.
