Ali Express Bluetooth Earbud

Another crazy-cheap item from Ali Express Built around a single integrated circuit from Bluetrum, the AB5656C2. Contains: A RISC V processor core Bluetooth interface Microphone A/D converter Speaker D/A converter Switching regulator power supply The Rest of the circuit board is a 26 MHz Crystal, a switch, a built in PCB antenna for Bluetooth and some discrete R, L,C: At $4.00 it's hard to believe…