Homemade Bluetooth speaker with your own hands. Homemade Bluetooth speaker

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In this article you will learn how to assemble an inexpensive wireless speaker with which you can listen to music from a smartphone, tablet or computer. The signal will be transmitted via Bluetooth.

Required components:

Small speaker with up to 3W power
- Board with Bluetooth module
- Smartphone battery or 18650 battery
- Amplifier with 8002B chip
- Buttons for switching music (3 pieces)
- Switch
- Micro USB port for charging
- Wires
- A box or round plastic jar (for example, cosmetics)

First prepare the body. If using a jar, cut a hole in the lid for the speaker or make many small holes in the lid. Secure the speaker with bolts or glue.

Solder wires to the pins on the Bluetooth board that lead to the power, speaker, switch, and switches. These contacts are marked on the board or indicated in the instructions for it. The wires going to the speaker should be longer than the others as they will get twisted if the jar has a screw cap.

Make holes on the case for the power port and switches. Solder the components to the wires and attach them to the case using hot glue. Also fix the board and battery with glue inside the case so that they do not dangle.

Charge the speaker using the USB adapter and check the functionality of the speaker. If everything is done correctly, it will connect to the smartphone and output sound. If desired, the jar can be painted with spray paint so that it is difficult to guess that it is a homemade gadget.

To prevent the body from slipping, you can attach legs or rubberized material to its lower part.

Let's talk about the introduction of wireless technologies. Specifically, we will talk about sound transmission via Bluetooth. For example, there is an old radio in your car that never even dreamed of Bluetooth. What can be done in this situation? Of course, you can buy a modern model. Well, what if you are not ready for this step or your car has a non-standard shaped radio, the replacement of which is not so easy to find? And if at the same time you are not averse to working with your hands, then this is definitely the place for you.

What is needed for modernization

Firstly, of course, the radio itself. The task will be easier if your radio has an AUX output. I will have to upgrade a very old model, which naturally does not have an AUX output. Therefore, I previously implemented AUX in it.

Let's not get distracted by how to do this, since this is a topic for a separate discussion; the relevant materials can be easily found.
We also need a Bluetooth adapter (“whistle”). The first model that came to me was unsuccessful. The audio output turned out to be single-channel (mono), and the model was unstable. I just had to throw it away. The one I ordered turned out to be quite good. This is what I will be introducing into the radio today.

Description of the connection process

Connecting the signal will not be difficult even for a beginner. “Ground” can be connected both to the body of the radio and to the AUX connector. We connect the left and right channels of the Bluetooth module to the corresponding contacts on the radio connector. Don’t be afraid to confuse the channels with each other; in my opinion, this is not important for listening to music. Particularly meticulous radio amateurs can get to the bottom of the truth and make the connection correctly.

The most serious need to approach the issue of powering our module. In the case of a 5-volt Bluetooth adapter, you can connect to the USB connector of the radio, if available. You can also try to find a 5-volt linear stabilizer on the radio board. The marking of this element may contain the numbers 7805. Of course, it is not a fact that it has the reserve power necessary to power our adapter. The best option is to additionally buy such a stabilizer and assemble the circuit shown here.
As for the XS-3868 module that I have, the situation is somewhat more complicated. The supply voltage required for it is 3.6 - 4.2 volts. This is unlikely to be found on the radio board. As far as I know, there is also no integrated linear stabilizer for 4 volts, at least among widely used devices.
It follows that I will have to assemble the power source myself. To do this, I took two electrolytic polar capacitors, two ceramic non-polar capacitors and a very useful LM317 microcircuit. In addition, you will need a pair of resistors to set the required output voltage. I took one with a nominal value of 1.5 kOhm, the second with a nominal value of 3 kOhm. Attached is a link to a calculator for LM317, where you can select resistor values. There is also a diagram of a voltage stabilizer based on LM317.

I assembled this circuit using the surface-mounting method, simply soldering the parts together.

The permissible input voltage for LM317 reaches 37 volts, which creates a large margin of reliability, since in the vehicle’s on-board network this value is no higher than 15 volts. At the output of my homemade stub, I found 3.95 volts, which is exactly what I needed.

Now you can connect Bluetooth and make sure it works. I supply power to the circuit and look for available Bluetooth devices on the phone. A password is required to log in. In 99 cases out of 100, standard for such devices the password is four zeros (0000).

Having connected to Bluetooth and connecting the headphones, I launch the sound file on the phone. As a result, I get a real stereo signal. The sound quality personally suits me quite well.
I came across information on the Internet that this Bluetooth module, when turned on, can briefly consume current up to 1 ampere. For this reason, I chose the LM317 chip, rated for current up to 1.5 amperes. I could not verify the presence of a current surge when turned on, since I do not have an oscilloscope, and the multimeter does not respond to such short surges. Constant consumption in operating mode, according to my observations, does not exceed 70 mA.
The XS-3868 module has additional capabilities that I also decided to use. In particular, there are contacts for connecting a microphone, after which our module can work as a Bluetooth headset for talking on the phone.

In addition, there are a number of options that I did not use, but someone may find them useful:

possibility of connecting indicator LEDs;
built-in lithium battery charger;
connection of volume control buttons, “next track”, “previous track”, “pause” buttons.

Next, I select a suitable microphone from the failed headset. I chose a microphone already installed on a small board. I think that in this version it will be even more convenient to attach it.

I glued the microphone board into the end of the front panel of the radio.
To install the stabilizer and Bluetooth module, I found free space on the radio board and used double-sided tape.

I wrapped the stub with electrical tape so as not to accidentally short-circuit anything. There is no risk of overheating due to the large power reserve. All that remains is to connect the stabilizer to the power supply. Everything is clear with the ground, it is on the hull as always. Now let's look at the plus. If you simply connect to the plus of the radio, you will get constantly working Bluetooth in all modes when the battery is connected to the car. The radio requires this to save various settings and clocks. For our Bluetooth module, this is also acceptable in principle, but it is completely irrational. Therefore, we find the red wire from the ignition switch, the voltage on which appears only when the key is inserted, and connect the plus of the stub to it.

That is, we insert the key into the ignition and our Bluetooth starts along with the radio. Well, we figured out the connection.

In my version of the upgrade, it is necessary to somehow provide an AUX output, because this radio did not initially have it. I solved this problem as follows. I simply connected the AUX connector to a 10-centimeter wire behind the rear panel of the radio. For those who had the AUX mode present initially, this “collective farm” will not be needed.

To check the system, switch the radio to AUX mode. In my version, this is radio mode plus an additional switch. We use the system as follows: if we need AUX, we don’t play anything via Bluetooth, and vice versa, if we need Bluetooth, we don’t use AUX.
Well, that's all. All that remains is to install the radio in the car and enjoy the new function.

Conclusion

Links you may need:

Watch the video

Everyone brainiacs greetings! I’ll tell you today how, after almost two years of studying the topic, designing and testing, I made my own version of a Bluetooth speaker. Gives out mine homemade 40W of sound from paired tweeters, woofers and passive membranes, equipped with Bluetooth 4.0 with smart options, a “long-lasting” lithium-ion battery, and everything is “packed” into an elegant plywood case.

Characteristics brain games:

Yamaha amplifier 2x20W,
Bluetooth 4.0 module with battery charge indicator and grounding insulator,
battery of 3 lithium-ion batteries with protection circuit and fast charging,
20W low-frequency speakers paired with tweeters and passive membranes,
6 hours of operation at full volume and 12 hours at medium volume.

How does it sound homemade? I will say that it produces sound even better than some high-quality industrial speakers, and to see this, watch the video presented!

How is this Bluetooth speaker different from other homemade speakers?

1. The Bluetooth module has a grounding insulator, which eliminates interference coming from the module itself, which affects most other similar devices. crafts. The same speaker has 100% pure sound.

2. You can monitor the battery charge level using your smartphone thanks to the smart monitoring option.

3. The speaker produces “uncompromising bass”, because it was specially designed to amaze with a very impressive sound, surpassing even industrial speakers.

4. The components used are cheap and reliable.

5. Homemade Easy to assemble/disassemble, just unscrew the screws.

6. Long operating time on one charge, and charging itself is quite simple.

Step 1: Required Components

All proposed parts have been carefully tested for compatibility and work perfectly in this combination. What is needed:

high-frequency speaker (“tweeters”) - 2 pcs.
Bluetooth module with grounding insulator
voltage boost module (boost converter)
plywood 18mm thick
plywood 3mm thick.

Templates for laser cutter.

Step 2: Design the Front and Back Panels

On the body design of this brain games I was inspired by layered wood. Looking at it, you might think that it is assembled from 10 layers folded together, but in fact the body consists of three layers of 18mm plywood, which are glued together, and two more layers of 3mm plywood on the front and back sides . The design of the case is such that it has a volume of about 2.25 liters, which is perfect for electronics and selected passive membranes.

Making the front panel:

The fastest way to create panels is laser cutting, and my laser cutter could not cope with plywood thicker than 3mm, so for greater strength, I made the front panel from two glued parts, which was additionally reinforced with MDF strips. I note that all the wooden parts in this brainproject glued together only with wood glue. The front panel has holes for tweeters and low-frequency speakers, as well as for access to electrical components. On the back panel there are holes for passive membranes, as well as small holes for the charging connector and switch.

If you are designing panels of your own design... then I would still recommend making a hole for quick access to the electronics homemade products, which is very useful if something requires adjustment or repair.

Step 3: Making the Side Panels

After this I started creating the side panels and made them from high quality 18mm plywood. Each layer of this brain plywood 3mm thick, and its outer sides are thin veneer. I also recommend that you use high quality plywood, since the inner layers of the “sandwich” body must be quite hard and tightly compressed. When cutting lower quality plywood, it will split or even fall apart into layers. To cut out the side components of the body, you only need a jigsaw and a drill with a crown or wood drill.

First you need to attach the front panel to the plywood and trace its outline, and then repeat it inside at a distance of about 8mm from the outside, it can be thinner or thicker, depending on the quality of the plywood itself and your experience (you will quickly figure this out). Then you need to drill 4 holes in the corners of the internal contour, so that part of the circumference of these holes coincides with the internal contour, and then use a jigsaw to complete the contour completely.

Having cut out the inner contour, the part is cut out of a plywood sheet along the outer contour.

Step 4: Gluing the Side Panels

The side panels are simply glued together with wood glue, lots of wood glue. The coated panels are stacked and pressed tightly with some kind of weighting agent, or compressed with clamps, and left in this state until the glue dries.

When the side of the body homemade products When it dries, the protruding parts are ground off with a jigsaw or on a circular table so that it takes on an even, streamlined shape. This can also be done by sanding, but then it will take more time. Next, the inside of the side part should be covered with a thick layer of wood glue, so that after final assembly brain trick was sealed.

Step 5: Preparing the Back Panel

Passive membranes are glued to the back panel, which are an alternative to a bass reflector and allow you to expand the frequency range of the speakers, but in a more compact version. They do not require connections to electronics, they simply respond to pressure changes within the housing (that is, when the main speakers move outward, the membranes are pulled inward, and vice versa). And therefore it is very important that the finished body brain games was 100% sealed.

Passive membranes are glued to the panel with super glue, in this case it is better with gel super glue, since it is not so rigid and allows slight movements, unlike regular super glue. You should also add several MDF strips to the back panel so that it does not bend, using the same gel super glue. After all, any vibrations of the body will spoil cerebral sound.

Step 6: Electronics Placement

As you can see in the presented photo, inside the case crafts there are quite a lot of electrical components located. Before you place all that electronics, it's important to find the correct position for each component and make sure everything fits as it should! It is also important to find such a position for the electrical parts so that they can be accessed for repairs if necessary.

In this brain work I placed parts so that boards such as the amplifier and Bluetooth module were easily accessible, and placed the crossover, which most likely would not need to be checked, further away from the service hole. This crossover is located directly under the hole for the right subwoofer, so if necessary, you can still access it by unscrewing the speaker itself. The remaining electrical parts are located under the service opening, that is, they are easily accessible.

Step 7: Circuit Diagram

The figure shows a diagram for assembling an electrical circuit homemade products. If you use the same components as in the proposed parts list, then assembling the electrical circuit is quite simple, you only need a soldering iron and solder (well, and cable ties to make everything more neat). The length of the wires depends on how you arrange the electrical components, you just need to know that the smaller the wire allowances, the better.

If you don't know much about electronics, or want to understand it better, then read the following steps. And if you are not interested, then feel free to skip the theory.

Step 8: Battery Pack Operation

For many people, using lithium-ion batteries safely seems confusing, but it's actually not that complicated. Three things are important for lithium-ion battery packs:

1. The actual batteries.

2. Battery protection board.

3. Charger for lithium-ion batteries.

Purchasing lithium-ion batteries is very important, as there are many counterfeit batteries sold online. Therefore, the easiest way is to choose cheap, but at the same time real and reliable batteries, for example, Samsung’s pink 18650. Because they are cheap, then counterfeit them, that is, create even cheaper ones brain copies, not profitable. And as a result, we have inexpensive, reliable branded batteries.

The next point is the battery protection board, which prevents it from overcharging, over-discharging, short circuiting and much more. The exact protection functions vary slightly between boards. Such protection boards are a mandatory element, because lithium-ion batteries are very sensitive and require special conditions for their functioning, and without a protection board there is a risk of the battery catching fire/exploding, or it will simply “die”.

And finally, the charger itself for lithium-ion batteries is also important. These chargers directly charge brain batteries, and also, depending on their voltage, reduce power or completely stop charging, so you should make sure that your device for lithium-ion batteries is a CHARGER, and not a power supply. Many devices on the network are sold as chargers, but in reality they are ordinary power supplies, so when choosing and ordering this device, be sure to read the characteristics and description!

For more information on charging and using lithium-ion batteries, go here.

Step 9: Assembling the Battery Pack

Before you begin soldering the battery pack, you must make sure that brain strain all batteries has the same value, since otherwise it will confuse the protection board and may “kill” the battery during charging. If the battery voltage is slightly lower than required, then by assembling a special circuit, you can charge it separately and achieve the same voltage on all batteries.

Having balanced the batteries, you can begin assembling the battery pack. A battery case like this is worth purchasing, because it keeps the batteries compactly in one place; I only recommend resoldering the wires to thicker ones so that they can withstand the required power.

According to the above diagram, a protection board is soldered to the battery case, as well as a switch and power connector. When soldering the latter, be sure to do it correctly! (For better understanding, see photo). The right pin (bent) can be removed, the left pin goes to ground, and the middle pin is positive. Before soldering the connector into the protection circuit, you should place the charger in it and check the voltage with a multimeter to ensure the correct polarity of the connector contacts.

Next, to check the functionality of the supply circuit in braincase the batteries are inserted, and if everything is correct, the wires are compactly attached with tape to the back of the case. After this, a boost converter is soldered, after connecting it, you need to measure the voltage at its output contacts with a multimeter. The voltage we need is 14V, and to get it we need to tighten the copper screw on the converter module board with a small screwdriver until the required parameter is obtained. Everything is the same as in the next view, only the board is different.

Step 10: Connecting the Bluetooth Module and Amplifier

To save space inside homemade products and the compact arrangement of parts, I attached the Bluetooth module to the amplifier board. If you decide to place them in this way, then leave enough free space between the amplifier and Bluetooth module chips, since both chips require air flow for cooling, and a short circuit may occur if they come into contact. I attached the module and amplifier boards to each other using hot glue. If you use a Bluetooth module from any other brain games operating from 5V, then I strongly recommend connecting a grounding insulator to the module power wires to avoid unwanted interference from the module chip.

The output contacts of the module are connected to the input contacts of the amplifier. If you want to use the additional functions of the Bluetooth module, now is the time. The easiest way to do this is to solder the buttons together, as shown in the photo. Next, the power contacts of the amplifier are connected to the output contacts of the boost converter, that is, the amplifier will be powered from 14V. But the Bluetooth module, depending on the voltage on the battery, will receive 10-12.6V, since it is connected to the input contacts of the boost module.

This voltage variation will be “monitored” by the module, and if you have the latest version of Android, information about the remaining battery life of the speaker will be displayed next to the Bluetooth icon on your smartphone. The Bluetooth module will work until the voltage drops to 10.5V, and it works great with 3S batteries. DO NOT connect the module to a 14V power source as it is rated for a maximum of 12.7V!

Step 11: Connecting Crossovers

Let's move on to crossovers, which will separate the sound signal into high and low frequencies for the tweeters and low-frequency speakers, respectively. Once they are soldered, they can be used like other parts. homemade products, glue with hot glue. The switch and power connector are attached with the same glue. Once again I emphasize the importance of 100% tightness brain games, which is perfectly achieved using hot glue!

Step 12: Gluing the Side Panel

The time has come to glue the side panel, and to do this, wood glue is applied to the rear panel along the edges and it is pressed against the side panel. After the glue has dried, the seam from the inside of the case is sealed with hot glue, this will also add strength to the case itself.

Step 13: Preparing the Front Panel

As mentioned earlier, strips of MDF can be glued on to give the front panel a look. Next, the “squeakers” are glued to it, and since they are motionless, this can be done with hot glue. The tweeters themselves should now be connected by wires to the crossovers, since after attaching the panel to the body this will be impossible. But it’s not worth screwing in the low-frequency speakers yet; this will be done later, as soon as everything is glued and connected.

The edges of the front panel are coated with glue, it is pressed against the body crafts, and everything is left to dry completely.

Step 14: Service Port Cover

When the glue has dried, you can mount the low-frequency speakers - first connect the wires to them, and then secure them with screws. After testing the almost finished homemade products and having received positive results, the cover is screwed on to cover the hole for servicing the electronics. After that brain trick cleaned and, if desired, coated with clear varnish to preserve its natural wood look.

All that remains is to say: ready! And, again at your discretion, you can attach fabric to the speaker and grille on the speakers by adding several additional layers of 3mm plywood, and glue the fabric to the underside of the top one.

Step 15: And finally for inspiration

I've written a few more on the topic of columns brain guides, by reading which you can get more ideas. And of course, if you are interested in this topic, you can find me on various

The presence of Bluetooth (blue tooth) in modern devices has long been considered the norm. Almost all mobile devices are equipped with such modules. Why do we need it, this Bluetooth, is a question that any first-grader can easily answer today. A desktop PC, unlike laptops, netbooks and tablets, is equipped with “blue-tooth technology” as an option. The absence of this option is not a reason to shed bitter tears over your pet’s system unit. It is possible, using a Bluetooth adapter, to make available all the amenities that this technology provides to its users in a few minutes.

How is this possible? This will be discussed in our review. But first, a little history. Bluetooth technology is a way to transfer information, control devices, connect multiple devices to a local network, etc. All this can be done without using a wired connection. Back in 2000, several companies first announced devices with this technology on board. At that time, it was simply fantastic: transferring files wirelessly was beyond comprehension.

A little more than ten years have passed and Bluetooth as a wireless technology has become commonplace. keyboards, mice, printers, cameras, laptops - all these (and not only these) devices can now work and “communicate” with each other without wires. Despite the fairly advanced age of the technology, it still enjoys well-deserved demand and popularity among manufacturers and consumers. The undoubted advantages of the “blue tooth” include stability of operation, minimal impact of interference on the operation of devices, as well as the low cost of such equipment.

If a computer or laptop is suddenly not equipped with a Bluetooth module, this defect can easily be corrected by a Bluetooth adapter. And for this you need very little money. On average, for $5-10 you can purchase a Bluetooth adapter that connects to a PC via a USB port. The miniature nature of some models allows them to be used as portable devices; they are almost invisible and do not cause any inconvenience. When the need arises to use Bluetooth, with a slight movement we insert the adapter into the USB port and... that's it, complete freedom from the ever-tangling wires.

What is required for installation? Minimum kit:

Device driver and software for operation (included);
Free USB port on your computer/laptop.

The installation procedure is simple. A Bluetooth adapter is inserted into the USB port, and an installation disk is inserted into the disk drive. We launch the installation program. We agree with all the suggestions and continue the installation anyway, even if suddenly “...the equipment has not been tested...”. After installation is complete, you need to check that the Bluetooth adapter is in the list of devices.

Now you can easily connect various devices to your PC, send and receive files, use a communicator or mobile phone modem to access the Internet, which is very important in the absence of alternative options for accessing the Internet.

Among competitors in the wireless market, two trends can be noted: the gradual departure from the scene of infrared communications (IrDa) and the steadily growing popularity of the IEEE 802.11 standard (aka Wi-Fi).

Through the infrared port it loses its relevance - devices should only be in line of sight, the transmission speed leaves much to be desired. Manufacturers have practically stopped installing it in their devices. We can say that it has been successfully replaced by Bluetooth.

Which is better, Bluetooth or Wi-Fi, is not the question. These two wireless communication standards have been living peacefully in a “civil marriage” for many years, sharing responsibilities among themselves. Wi-Fi is a local network and Internet access, Bluetooth is data transfer, Hands free, connection with various computers, etc. This symbiosis provides customers with one clear benefit - most devices with this sweet couple “on board” provide the maximum degree of freedom. By the way, you can install both a Bluetooth adapter and a Wi-Fi module on your PC yourself. But this is a completely different song...

From an old bluetooth headset with a 3.5mm jack audio connector.

I think it’s no secret to anyone how a bluetooth headset works.
This article describes how to make a more versatile device for wireless music playback while maintaining headset functionality.

This homemade product will be useful for drivers (for making and receiving calls through the standard audio system), for listening to music through an AUX connection or on headphones.

We will need:
1. Bluetooth headset
2. Audio connector 3.5mm jack
3. Pair of wires
4. Heat shrink
5. Super glue

From the tools:
1. Soldering iron

Step 1.
We will need a 3.5mm jack audio connector. You can get it from old equipment, as I did, or buy it at any radio store.

Step 2.
We carefully remove the speaker from the headset and unsolder the wiring from it.

Step 3.
We place our 3.5mm jack audio connector most conveniently and solder the wiring according to the pinout and glue it with super glue.

Pinout

Since the headset produces a mono signal (for one channel), we will combine the right and left channels into one, soldering them together with wiring. The photo shows that two red wires are soldered to one channel. One goes to the headset, and the second connects the right and left channels. Now the mono signal from the headset will be sent to both channels. If this is not done, then when listening to headphones only one side will play, the same with any audio system.

Step 4.
Now we put on heat shrink to insulate the contacts and aesthetically appearance.

This completes the modernization. Connect headphones or AUX cable and check.

The built-in battery will not work for long. Therefore, take care of additional power supply to the receiver for long-term operation.

Video recording of step-by-step assembly and operation of the device for reference.