
Step 4: Install the Bluetooth module.
Place the components of the Bluetooth module face up on the circuit board.
Step 5: Install electrolytic capacitors at C2, C3, C4, C5, C6, C7.
Note: The long leg of the electrolytic capacitor is the positive pole, and the short leg is the
negative pole.
On the corresponding installation position of the circuit board, the side of the hollow
semicircle is connected to the positive pole, and the side of the semicircle with shadow is
connected to the negative pole.