Combo of PAM8403 with Bluetooth stereo audio receiver and charger module with Micro USB 5V 1A Lithium battery charging converterPAM8403 - This is a 2-channel, 3W, class-D audio amplifier. It provides high-quality sound. Because the new filter-less architecture, allows the device to drive the speaker directly. Operating voltage for this module range from 2.5 V to 5.5 V. Also, it can extend the battery life, which makes it well-suited for portable applications. Moreover, it is an ideal module for adding the audio capability to your MP3 and MP4 player projects.
KCX BT002 - This is a very small size Bluetooth chip module. This is a multi-purpose Bluetooth audio receiver circuit module with Bluetooth, audio, and BTcall. The operating voltage of this module is 5V Max. This module supports all kinds of smartphones in the market. This module can play music, supports teleservices like answering the call/cutting the call, and other functions. It can be used to upgrade normal audio products into a wireless Bluetooth audio device.
TP4056 - This is a complete constant-current or constant-voltage linear charger for single-cell lithium-ion batteries. The charge voltage is fixed at 4.2V. But you can program the charge current externally with a single resistor. It automatically terminates the charge cycle when the charge current drops to 1/10th. Other features include a current monitor, under-voltage lockout, automatic recharge.