Adding CSR8645 or CSR8675 module board to AUX-IN/USB box

Tws Two Box Bluetooth-compatible 5.0 Power Amplifier Board 2x15w / 10w Support Aux Audio Input Support Serial Port Change Name - Integrated Circuits - AliExpress

CSR8675 programming guide w. software and tons of CSR info, Page 8

SOTAMIA Bluetooth Decoder Board DAC QCC5125 QCC3031Bluetooth 5.1 Audio Receiver ESS9018 Decoding LDAC APTX-HD APTX 24Bit 96Khz - AliExpress

Programming off the shelf CSR8635 module

Bluetooth Power Amplifier Board Module 4.0 Audio Receiving CSR8645 Aptx Dual 5W Sound Box Sound Amplifier Nondestructive - China CSR8645 Aptx, Module

Products – Page 8 – diymore

Bk3266 Bluetooth 5.0 Power Amplifier Board 5w+5w Support Aux Stereo Audio Support At Change Name And Password Button Switch - Integrated Circuits - AliExpress

Tws Two Box Bluetooth-compatible 5.0 Power Amplifier Board 2x15w / 10w Support Aux Audio Input Support Serial Port Change Name - Integrated Circuits - AliExpress

CSR8645 Bluetooth 4.0 AAC APT-X Module / Baseboard

Qcc5125 Bluetooth Module, Bluetooth Ldac Amplifier

CSR8645 Bluetooth V4.0 Amplifier Board Module APTX 2*5W for DIY Bluetooth Sound Box

CSR8645 Bluetooth 3.0/4.0 Amplifier Board 5W+5W APT-X Stereo Receiver – Aideepen

CSR8675 programming guide w. software and tons of CSR info, Page 11