The USB Bluetooth audio adapter allows you to turn any amplifier into a wireless gadget for sound reproduction. USB Bluetooth stereo adapter can be connected to a car radio, a music center, to an active speaker system and play sound from a phone, player, game console, laptop, etc.

By using the USB Bluetooth Wireless Stereo Receiver, you instantly get rid of unnecessary wires, enjoy digital stereo sound quality and all the pleasures of wireless control. The Bluetooth adapter has a small size and is made in the form of a flash drive, which will allow you to take it with you wherever you go.

Connection.

To connect, you need to insert the Bluetooth adapter into any USB input to receive power. Then connect the audio cable to the AUX input of the amplifier. All manipulations will take you no more than a minute. For power, you can use a separate power supply, say, from the same cell phone with USB output. AUX is a line input, now there is almost any device where there is a power amplifier, so it will not be difficult to find it. Once connected, the adapter LED will flash at short intervals to indicate readiness for use.

Pairing.

Search for bluetooth devices on the device you want to stream music from. In the list found, select "dmzmusic", if when you try to connect a window asking for a password appears, enter "0000", after which the pairing will be performed (the LED on the bluetooth receiver will blink with a long interval). Now you will be able to play your music through the amplifier speakers.

A few days ago we came from the GearBest online store Bluetooth audio modules XS-3868 Ver.3.0 based on OVC3860. Modules represent a device to which you can connect via Bluetooth and transmit an audio stream “over the air”. The cost is approximately $ 3.5. The small size and power supply of the module, fully adapted for operation from 3.7 V Li-Ion batteries, allow, in my opinion, to embed these modules into a huge number of their devices: these are home-made Bluetooth headsets, and wireless and portable speakers, and a wireless interface. for speakers and players, and some kind of intercom (if, of course, the range of work suits), and everything else that the imagination of a radio amateur can reproduce.

Specifications of Bluetooth audio module XS-3868 based on OVC3860:

• Frequency 2.402 ~ 2.480 GHz
• Transmitter power 4dBm (PCB antenna), Class2
• Receiver sensitivity -82 dBm
• Module size 30 x 17 x 3.4 mm
• Bluetooth: Version 2.0
• Radius of action approx. 10 m
• Data transfer rate up to 3 Mbps
• Possibility to connect an external antenna via SMT pad
• Ability to connect a mono microphone
• Audio flow and volume control (with buttons)
• Module operation indication by two LEDs
• Stereo audio output (designed for 32 ohm headphones - built-in 40mW headphone amplifier)
• Supply voltage 3.6 - 4.2 Volts
• Consumption current up to 55 mA in audio playback mode
• Standby current consumption less than 10 mA (actually less than 1 mA)
• Transition time to power saving mode 5 min (if nothing is playing)
• Profiles: A2DP V1.2 – Sink Only, AVRCP V1.4 –Controller Only, HSP V1.2, HFP V1.5
• UART connection speed 115200 baud (used mainly for debug)
• Built-in 20 bit stereo DAC
• Built-in 16 bit mono ADC
• Built-in battery charge controller Li-ion, Li-Pol, charging current up to 150 mA
• Connection password 0000

The characteristics of the module copy the characteristics of the Bluetooth controller OVC3860.

The module has the following pinout:

Module pin assignment:

• 16, 17, 19 - stereo audio output (for headphones, not every audio system will pull it, so when connecting to some speaker systems, you will have to add a preamplifier, unlike headphones, the 5.1 microlab system refused to work normally with this module when connected directly)
• 22, 23 - contacts for connecting a microphone (Bluetooth headset after all)
• 24, 26 - contacts for connecting LEDs
• 25 - 5 volt power input for battery charging
• 31 - earth
• 29 - battery plus
• 33 - 1.8 volt output
• 35 - reset contact
• 36, 37 - contacts of volume control buttons
• 43, 44 - UART interface
• 52, 54, 55 - contacts of audio stream control buttons

To start using a Bluetooth device, you do not need to do any complicated actions, you just need to connect the power (battery), a 4.7 kOhm - 10 kOhm resistor between the 1.8v out and rst pins, and a headphone jack. By default, the module is visible to other Bluetooth devices as POR 1007BT. We connect, enter the password upon request. The module is defined as a headset, and when connected, the sound will be transmitted "over the air". If you connect only power and headphones without the module buttons, then the volume will automatically be at maximum. It all depends on the device to which the module is connected. So when adjusting the sound level on the tablet, the sound is also regulated on this Bluetooth module, and when connected to a phone (Philips xenium x130), the volume level simply remains at the maximum or just turns off as if you do not adjust the volume of the audio file playback.

Here is the simplest circuit for switching on the module:

Using a few more pins of the Bluetooth module, you can make a slightly more functional device with buttons and LED operation indication, diagram:

And then, simply by adding a microphone, connecting it to the corresponding pins of the Bluetooth module, using the appropriate microphone activation scheme, you can use the device as a full-fledged Bluetooth headset for talking on the phone, for example. By the way, you can estimate the size of the parts and see that the size of the device is not larger than many factory copies.

Although the module has the ability to charge a small battery, it is not very profitable to use this function here: 1) nothing is reproduced in the charging mode, 2) a small charging current, which means only small batteries can be used, 3) switching to sound playback mode after charging requires additional action - either disconnect and connect the headphones, or press the reset button, which will have to be done, or just distort the power. In my opinion, it would be better to additionally use a charging circuit for the battery, for example, based on TP4056:

The dimensions of such ready-made modules are small and they are smaller than the batteries themselves, even of small capacity. Therefore, I believe that this is a slightly better option than the built-in Bluetooth function of the module.

If you use such a module, then you must observe two nuances: 1) without a battery, it is impossible to turn on the charging module connected to the Bluetooth module, since the voltage without a battery at the output of the charging module can exceed 4.2 volts; 2) set the charging current for the used battery. The charging current is regulated by a resistor connected to the second pin of the TP4056 microcircuit. By default, a 1.2 kΩ resistor is usually installed on the charging modules, which corresponds to 1 A of charging current. 1.5 kOhm - 780 mA, 3 kOhm - 400 mA, 10 kOhm - 120 mA, 20 kOhm - 70 mA.

If you do not want to use the Bluetooth module as a portable device with a battery, then instead of a battery, you need to make a power source for 3.7 - 4.2 volts, add capacitors to the power nodes to the circuit and use it as a stationary device.

Thus, for a small cost, you can get a DIY (do it yourself or do it yourself) kit for wireless audio transmission via Bluetooth.

Below you can download some documentation on the Bluetooth module. I hope this small overview will be useful in finding solutions for radio amateur purposes.

Progress is definitely a beneficial phenomenon. Unfortunately, it has side effects. In particular, one has to put up with the fact that now the obsolescence of many electronic devices is much faster than their natural wear and tear. Take, for example, the music centers or complexes of stationary sound-reproducing equipment that many people have at home. Such devices are capable of faithfully serving their owner for ten years or more. However, the rapid growth of the segment of mobile devices, combined with the rapid development of online services, has led to the fact that still fully serviceable and not very old audio equipment is gradually becoming less and less in demand.

Will this music be eternal?

The reality is that physical media with musical recordings is gradually becoming obsolete. And even at home, many people prefer to play sound recordings through mobile devices. At least for reasons of convenience: now it is possible to play your favorite music from online streaming services and social networks. Plus the widest selection of Internet radio stations, the number of which has already exceeded tens of thousands for a long time. And the more advanced users also have extensive personal music libraries on home NAS drives.

Naturally, in such a situation, the most convenient option for delivering a digital signal from a source to a sound reproducing device is a wireless connection. First, you don't have to look for the right cable every time. Secondly, you can move freely around the house without losing communication and control over playback.

Now let's look at a fairly typical situation. There is a not new, but still fully functional music center (as an option - a set of block audio equipment), the sound of which is completely satisfactory to you. However, due to the reasons stated in the previous paragraph, it is not very convenient to use this equipment with mobile devices. What to do?

Manufacturers of gadgets and accessories are ready to offer their solutions to this problem. One of them is to connect an external wireless adapter to the existing audio equipment. It receives a digital signal transmitted from a mobile device via a wireless channel, converts it into analog and, already in this form, feeds it to the line input of a music center or amplifier. Such an upgrade will extend the active life of high-quality sound equipment, providing the fastest and easiest way to connect your PC and mobile devices to it.

To test the performance of such a solution in practice, we decided to test one of these adapters produced by the famous Swiss company Logitech. The name of the model is simple: Bluetooth Audio Adapter (literally - "sound Bluetooth adapter").

Acquaintance

The Logitech Bluetooth Audio Adapter is shipped in a small cardboard box, decorated in a traditional white and green color scheme for this manufacturer. An interesting detail: instead of the usual cardboard or plastic tab, there is a black cord loop on top.

In addition to the adapter itself, the package includes: a 1.5 m audio cable (2 RCA - 3.5 mm mini-jack), a power supply, a quick user's guide and a warranty leaflet. All this is neatly arranged in the cells of a tray made of thin transparent plastic.

The compact (only 50 × 50 × 23 mm) body of the device is made of plastic. Without going deep into the description of the design (everything can be seen in the given photos), we will describe it in one word - “minimalistic”. The design uses a combination of two colors: black and bright blue.

The rear panel houses two RCA sockets, one 3.5 mm mini-jack, and a coaxial connector for connecting a power supply.

A wide rubber pad is attached to the bottom plane for better contact with the supporting surface. On the side there is a light indicator equipped with a matte diffuser.

There is a shallow niche in the center of the top panel, in which there is a button for activating the mode of establishing a wireless connection, marked with the Bluetooth logo.

Connection

The Logitech Bluetooth Audio Adapter connection procedure is straightforward, even for non-experts. First, you need to connect the cable from the standard power supply to the connector on the rear panel. The next step is to connect the adapter to the device to which you plan to broadcast audio. With two types of outputs (mini-jack and RCA), maximum compatibility is ensured. For example, multimedia speakers equipped with a built-in cable can be connected directly to the mini-jack socket. In other cases, the supplied connecting cable will help out. Depending on the type of connectors installed on the connected device, it can be connected one way or the other.

With the Logitech Bluetooth Audio Adapter, you can broadcast line-level audio to a wide variety of analogue-equipped devices - powered speakers, stereos, receivers, amplifiers, and more.

Logitech Bluetooth Audio Adapter connects to audio sources via a built-in Bluetooth 3.0 adapter that supports Advanced Audio Distribution Profile (A2DP), which provides two-channel (stereo) audio streaming.

When powered on, the Logitech Bluetooth Audio Adapter automatically enters wireless establishment mode, indicated by a blinking blue light. To establish a connection in the settings of the mobile device, you must enable the search for Bluetooth devices. After the list of found devices is displayed, it remains to select the Logitech BT Adapter item in it.

If the device used supports the A2DP profile, then after a short time a wireless connection will be established (in the examples given, an Android tablet was used).

If you later need to connect a new device to the Logitech Bluetooth Audio Adapter, you can manually activate the wireless connection mode by pressing the button in the center of the top panel.

In work

So, the equipment is connected, and now you can try the Logitech Bluetooth Audio Adapter in action. After starting playback of the recording on the tablet, we heard the sound from the speakers to which the Logitech Bluetooth Audio Adapter was connected. It is very convenient that the signal can be played from different applications - media player, web browser, games, etc. This allows you to listen to programs of Internet radio stations, recordings from streaming services (for example, Yandex. Music), etc. through an external speaker system or a music center. The sound volume is regulated not only on the end device, but also on the tablet. The latter option is more convenient, but does not provide high accuracy due to the small number of intermediate positions.

One of the features of the Logitech Bluetooth Audio Adapter model is the ability to establish a wireless connection with two devices at the same time (for example, a tablet and a smartphone). To switch the source, it is enough to pause the playback of an audio recording on one device and then start it on another.

During our tests, we connected the Logitech Bluetooth Audio Adapter to an inexpensive active speaker, a music center, and a set of blocky hi-fi equipment. In all cases, the adapter did its job perfectly, providing uninterrupted and high-quality sound reproduction. The wireless connection works stably within a medium-sized room (18-20 m2) and even in adjacent rooms (through a concrete wall).

Conclusion

As we have seen from our own experience, the Logitech Bluetooth Audio Adapter is a really convenient and extremely easy-to-use device that can act as a link between modern gadgets and sound-reproducing equipment of different classes - including active multimedia speakers, stereos, receivers and amplifiers.

The main advantages of the Logitech Bluetooth Audio Adapter are high sound quality, ease of connection and the ability to establish communication with two devices simultaneously. It is also worth paying attention to the small size and excellent appearance. I would like to say special thanks to the developers for a very delicate light indicator that does not hit the eyes.

The disadvantages of the Logitech Bluetooth Audio Adapter model can be attributed only to a non-standard connector for connecting a power source, which is why the adapter is able to work only with the unit supplied. It is rather strange that the developers did not opt ​​for the more universal microUSB - in this case, the Logitech Bluetooth Audio Adapter could, if necessary, be operated in a mobile environment by connecting to the output of a portable battery.

Summing up the bottom line, we can state that the Logitech Bluetooth Audio Adapter is an excellent option that allows you to complement the capabilities of your existing audio equipment with a function of wireless connection to PC and mobile devices. Such an upgrade will cost significantly less than purchasing a new music center (and even more so an amplifier or receiver) with a built-in Bluetooth adapter, and will organically integrate sound equipment that is still in good working order into the ecosystem of modern gadgets.

MP3862BT - Built-in Bluetooth module for amplifier, active speakers or radio with hands free mode buy in Master Kit. Driver, programs, circuit, reviews, instructions, do it yourself, DIY

Here you can buy Master Kit MP3862BT - Built-in Bluetooth module for amplifier, active speakers or radio with hands free mode: price, photo, DIY, do it yourself, specifications and equipment, reviews, review, instructions, driver, programs, circuit

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MP3862BT
Built-in Bluetooth module for amplifier, active speakers or radio with hands free mode

Give a second life to an old radio tape recorder or active speaker.

Are available

Buy wholesale

Allows you to wirelessly receive and play audio files in mp3, wma, ogg, etc. from a phone or smartphones and PCs using Bluetooth technology.

The device has a hands free function. Thanks to this function, the plug-in amplifier can be used as a wireless headset. Using this module, you can upgrade your old audio system or radio tape recorder to the modern level. After such revision, it will serve you for many years to come. The board contains volume controllers. The module does not require a preamplifier. The module is built on the XS-3868 chip.

Specifications

Contents of delivery

• Assembled module - 1 pc.
• Instruction - 1 pc.

Preparation for operation

• Connect headphones or amplifier input to the output of the module.
• Apply 12V power, observing polarity.
• Turn on your phone and add a new Bluetooth device “POR 1007BT”.
• Play a song. Use the trimmers to set the desired maximum volume and balance.
• The check is completed with a pleasant operation.

Operating conditions

• Temperature - -15C ... + 50C pcs.
• Relative humidity - up to 95% non-condensing pcs.

Precautionary measures

• Do not exceed the maximum permissible supply voltage of the module.
• Failure to comply with this requirement will result in device failure.

Questions and answers

• Hello! Will this module remember the paired device when the power is turned off, so that when it is turned on it does not require re-pairing?
  • Alexander, this module remembers the paired device, re-pairing is not required.
• Good afternoon. Can you please tell me, maybe you are making external control buttons for this module? maybe you can suggest some kind of option? I need buttons in the car, it is possible to glue the buttons on a flat surface with a third-party tape. I will be grateful to you in advance.
  • Sergey, we do not supply buttons separately. Check them out in the assortment of our partner electronshik.ru
• Good afternoon, why can't you buy this product on your website?
  • We add the hands free function to the device. We expect the finished products to arrive at the warehouse by mid-summer.
• Will there be an improved model of this unit. For example, I'm interested in support for new codecs. Now new processors have already appeared and almost every smartphone supports them, and the module is still on sale old. Will there be a full-fledged line-out, for example, I really need it, since the volume of the module is much lower than the fm receiver in the car radio.
  • We expect this module to appear by mid-summer. The module will support all known codecs and will support hands free mode.

As an UMZCH, I used a stereo ULF of 20 watts per channel, which costs $ 20 on ebay. You need to disassemble it and inspect the inside of the case in order to understand where to get the power from the module and where, in fact, to place it. When everything is unscrewed, the amplifier looks like this.

Now about the bluetooth audio transmitter. It is bought ready-made.

All together - adapter and stabilizer, costs less than $ 8.

Disassembled Bluetooth audio receiver is shown in the photo. Connect 3 wires to the audio jack.

Now solder the wires from the USB cigarette lighter - charger.

They are both designed to be powered from 12 V. If the amplifier operates even from 24 V, it is still suitable. But if the amplifier operates from a higher voltage or is powered directly from a 220 V network, you will have to take the USB charger separately, or look for a reduced stabilized power supply on the board of the UMZCH itself. In general, you will figure it out yourself.

Now connect it to the bluetooth receiver according to the power supply on the board - this is 5 volts. Both modules are attached to an aluminum heatsink as the most massive element of the circuit.

The input wires are directly soldered to the amplifier's line audio out, but if you want to add a powered subwoofer or something similar, you need to drill a separate 3.5mm output in the rear panel. The bluetooth receiver itself is carefully fixed to a suitable place using hot melt glue.