Nowadays many acoustic speakers are sold that have a card reader. You can install a memory card or USB flash drive. This is of course great, but what if someone wants to listen to music from their phone? You need to pull out the card and insert it into the card reader. It's inconvenient. I decided to go a different route. I ordered a Bluetooth module from China. Entitled BK8000L. It is very convenient and has many functions. It has one drawback, a very minor one. Well, it’s okay, we’ll manage.
Will need
For the body I will need plastic. I have deposits.
I cut out several blanks from plastic. A pair with dimensions of 5*10 cm and a pair with dimensions of 3*5 cm. I will cut out the rest of the pair later.
To output the audio signal I will use two different jacks. One tulip-type connector cut from a large block.
The second jack is like on headphones, with a size of 3.5 mm.
To connect an external power supply, I will install a 5.5x2.1 mm connector.
To turn off the device you need a switch. I used it from an old lamp.
Here is the module itself. Compact and functional.
I almost missed describing the main thing.The device is self-powered, yes. I will feed from pairs of Li-ion batteries, with an approximate capacity of almost 4.5 Ah.
I'll charge controller from China. I have a board without protection. I applied separate BMS board.
Bluetooth receiver assembly
Let's move on to assembling the box. In one blank I make a cut for the “tulip” connectors and a connector like on headphones.
In the second blank I make a window for the power and charging connector.
Now we can glue our blanks. It turned out something like this. I glue the tulip connectors with super glue and soda. I'm trying on a 3.5 mm jack.
I cut out a window for a switch. I cut out the side blanks. I installed them temporarily and painted the body.
A few words about the diagram, in which everything is clear. The scheme is in principle available on the Internet. An external source is connected to the connector in the upper right corner, or you can connect micro USB charging to the controller. Power goes to the battery and through the switch to the module. The output signal goes to the output connectors. Whether it's a tulip or a 3.5 mm jack. The plus in the diagram is red, the minus is blue, respectively. We solder according to the diagram, everything is simple. Also installed Light-emitting diode. To indicate power on.
The controller was soldered to the battery. Connector for power supply to the controller. At the same time, I soldered the output connectors.
I glue the batteries, charge controller board and bluetooth module with thermal glue. I solder the wires to the switch.
Everything goes together very simply. If you have a soldering iron, it will not be difficult to assemble this design. I glue the side blanks. This is what the finished design looks like. Everything works perfectly. I connected it to a homemade amplifier and to a 2.1 system.
