Hello PCBWay community, this is Dario. I am an Italian electronics engineer, with huge passion for audio and music.

I did this project some months ago, the final result is quite nice, so I decided to share it!

During my years at NXP in the Voice & Audio solution department, I had the chance to put my hands on a nice amplifier, with excellent specs and little price: TFA9879. One of my colleagues was going to leave in few months, so I decided to make a special present for him, a personalized home-made Bluetooth speaker, good-looking and battery powered... that amplifier was perfect for that scope!

This was the outcome:

The heart of the project is a PCB with following main components:

• 2x TFA9879: I2S ClassD amplifier with DSP
• 1x BTM625: Bluetooth module with CSRA64215 chip from Qualcomm
• 1x LPC1343: Microcontroller with USB bootloader

Full documentation is available on public Github repository, including BOM and SMD positioning files, for automated assembly.

Compiled firmware and full source code for LPC1343 microcontroller is available too!

https://github.com/Darmur/bassowl-lite

USB bootloader mode can be selected closing jumper JP2 and connecting the PCB to a PC with USB cable. The PC will recognize the micro-controller as a USB drive, where firmware in .bin format can be copied for flashing the very first time or for updates.

Settings of the Bluetooth module, including Bluetooth name, can be changed following this guide:

After setting of micro-controller and Bluetooth module is finalized, PCB can be connected to loudspeakers, LEDs, buttons, microphone.and power! Details will be available soon on Github repository.

For making your Bluetooth speaker battery-powered, this module can be used together with a LiPo battery:

https://www.aliexpress.com/item/33037654930.html

It will charge the battery when USB is connected and it will provide required 5V to the PCB. Selecting a 3000mAh battery playback time will be several hours!

The rest is up to you! Chose your box, drill holes, assemble and paint! Enjoy!

Dario