[FreeSound] Young people's first Bluetooth speaker

Video introduction: https://www.bilibili.com/video/BV1xe4y1h7ed/?vd_source=25617b52e7e0b6d56790cc1bea5b5be1

Information address：https://github.com/ZhaJiHu/FreeSound

Information Description

• 3D model design files.
• Power module, audio module, touch module hardware engineering.
• DSP program files and ESP32 BIN files.
• Various documents and pictures.
• STL print files.

Structural Design

It adopts an omnidirectional loudspeaker cone design and produces sound in 360 degrees. In order to improve the bass, two 2-inch symmetrical passive diaphragms are used. A large number of 3D printed parts are used. The filling rate can be increased during printing, and the vibration will be less. emm. In order to avoid air leakage, it is best to add hot melt glue. For light transmittance, transparent 3M glue is used on the top, and a separate light isolation grid is designed for each LED.

• Provides a complete step design document.

Circuit Module

Power module:

• The battery uses a 2S lithium battery and a TP5100 charging module. The TYPE-C power supply uses CH224K. The default power supply is 12V.
• Using an ESP32, it mainly handles touch input, Bluetooth input, power on and off. In the future, it can also communicate with DSP and tune online.

Audio Module

• Using TPA3118 Class D power amplifier, 7.4V power supply.
• Using ADI ADAU1701 DSP IC, USBi can be used for online parameter adjustment, or it can be downloaded to EEPROM for self-starting.
• Bluetooth uses QCC5125 module to output I2S audio signal.
• Using SRC4192IDB to indirectly output MCLK to the DSP.
• Using FPC Bluetooth antenna.

Touch Module

• Using the BS814A-1 touch module, in order to get the maximum sensing thickness, there is no welding capacitor to ground.
• Using 28 WS2812B-2020.

Firmware Instructions

Due to time constraints this time, the code has not been sorted out yet, so the bin file of esp32 is provided first. DSP uses graphical programming. The project files have been provided. You need to download SigmaStudio by yourself.

Proofing Instructions

3D Printing:

• The file is located at: /6.Process**/3D printing, **The file is in STL format, and the quantity is 1.

PCB Printing:

• You can use the project file in github to export the Gerber file, or you can use the provided Gerber file. The file is located at: /6.Process**/**Gerber.

BOM

• Organizing.