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The first integrated circuit invented by the engeneer Jack S. Kilby1 (1923-2005) contained only a few transistors. Texas Instruments.
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Homemade bluetooth speaker, 3D printed case

0.0 Basic intro

This is a very low budget fully DIY Bluetooth portable speaker. It has a 3D printed case, and all the components inside are low cost. In a past tutorial we have build another Bluetooth speaker using this board with the TDA7492 amplifier. Now, I want to build another Bluetooth speaker but build my own circuit and also reduce its price. The TDA amplifier board from the other video was around 8 dollars which is not much. But I would like to lower the price even more using recycled old laptop batteries, unexpensive 3D printed case, and build my own amplifier circuit. To receive music using Bluetooth connection I want to hack this small and very cheap module. In this way, my project will be fully homemade and also for a reasonable price. So, let’s get started.

Homemade bluetooth speaker 3D printed case

1.0 What do we need?

I will talk a bit about all the components. You ahve a photo below with some of the components. For more details go to the page of the full part list. There you will find all the components, prices and different options.

See the full part list here:

Homemade bluetooth speaker part list

I can’t say that the receiver is the main part of a Bluetooth speaker. But we do need a Bluetooth connection and for that I’ve choose the small module below. This costs around one or two dollars. You could establish a Bluetooth connection between your smartphone and this device. Then play music and you will have the music signal on shown output. My idea is to connect wires for both right and left sound outputs and connect the signal to an amplifier.

bluetooth receiver 3.5mm

Now we should talk about the amplifier. I want to use the TDA2030 sound amplifier because it is quite cheap. Before we go farther I want to say that this amplifier is not the best, you could always use another one if you want and keep the rest of the project the same. The TDA 2030 only amplifies one channel so I should use two of them, one for the right and another for the left audio channels.

tda2030 circuit amplifier homemade

This is a basic schematic that I’ve mounted for this amplifier. Here we have the potentiometer that increase or decrease the input amplitude and by that, lowering or increasing the volume. So, if we want a stereo output we should have two circuits like this one. But I don’t want to have separate potentiometers to control the volume separately for each channel. That would be very awkward.

tda2030 circuit amplifier homemade

So, for that I will use af dual potentiometer so I could change the amplitude of the signal of both amplifiers at the same time. The good thing about this potentiometer is that It also has a switch integrated that could turn on and off the speaker. So, we won’t need a separated switch. Finally, I will use some lithium ion batteries that I savaged from an old laptop battery that I don’t use any more. I will use a module to safely charge the batteries and a boost converter module to increase the voltage for our amplifier since the batteries only have 3.7 volts. I’ve designed my own case for this project and 3D printed using PLA material and my Anet E10 printer. You can download the case STL files froma link below. I will use two 4 ohms speakers from an old audio platform that I don’t use anymore. The main idea of this kind of projects is to reuse any part that you can.

Downlad the STL files here: