3D Printed Simple 3W Bluetooth Speaker

Hello everyone!

This is my first instructables and I’m going to show you to build simple, small and nice Bluetooth speaker :). Last several months I worked on design and hardware, try a lot of speakers and amplifiers.

You will need next components:

1. 3D printed enclosure

2. 3W 40mm 4Ohm Speaker

3. Bluetooth Audio Modul DW-CT14+

4. LiPo charger with TP4056

5. 500mA 3.7V 503035 LiPo battery

6. 2kOhm 0603 resistor

7. 3A 250VAC Rocker switch

8. 4x M3x50 screws + 4x M3 nuts

9. 2 color LED with common anode

It’s wireless Bluetooth speaker, so we need a battery. I choose 500mA because it’s small battery and have enough capacity for 5 hours of loud music :)

Charging is doing by PC board with TP4056 and with microUSB connector. I believe you already seen they. Are amazing simple and useful for battery powered projects.

We’ll connect the wires from the battery to the charging board (see diagram). Our output wires from the charging board are connected to the Bluetooth module. But before they get there, we'll need to add a switch to turn the speaker on and off.

The last part of the electronics is to connect the Bluetooth module. It's easy, you have 3 cables with JST connectors! First one is JST-XH-2 with 2.54mm pitch for power and second one JST-PH-2 with 2.0mm for speaker connection. We will not use one piece because it is for second channel, which we won’t have. Pay attention for "+" and "-"!

I designed a box for the speaker, so

you can put everything up there! No problem! It is available to download on thingiverse.com

Let's start with the charger, you need to prepare it. You should first set the charging current. This charger has a standard charging current of 1A, which is a lot for our battery. Our battery has 500mAh capacity and the maximum recommended charging current is 1C, which means 1x500mA. According to datasheet TP4056 we’ll select the closest programming resistance for 500mA, so it’s 2kOhm for 580mA. Attention! The resistance is too small, so carefully unsolder it and solder the new one.

If you want to know when the battery is charging and when it is already charged, you should solder a two-color LED, see diagram and pictures. But first, you need to unsolder the old LED from the board.

Keep going!

Do you have it done? So, we can continue! Scheme - that's our way.

Solder the red wire from the battery to the charger "BAT +", then the black wire from the battery to the charger "BAT -".

Then charger "BAT +" to the rocker switch, from the switch to the Bluetooth module "BAT +" and the module "BAT -" to the charger "BAT -". Lastly, solder "Lout +" to the speaker "+" and "Lout -" to the speaker "-". Or "Rout," it does not matter.

Before you put the speaker into the box, drill holes for screws. It’s easy, there's only a 0.2mm layer for better printing. Right after it, put here nuts.

When you've done everything, try put all to the enclosure. It's OK? If you have cables too long, remove and cut them, then resolder and try again. Does it fit perfectly?

Better if you try it now! Turn on the speaker, take your phone and search for a Bluetooth device called "DW-CT14 +". Connect and try to play a song. Does it work? Great! We can continue!

Secure all parts with the glue gun. Pay attention to IC TP4056. Do not gluing him, it needs to cool. Also try to seal the microUSB connector with something like plasticine. But do not put it in the connector!

Screw the enclosure with 4 screws.