Power
1. The module has a Micro USB interface and can be powered by a computer USB.
2. The corresponding ports of the module (marked on the PCB board)-and + are respectively connected to the negative and positive terminals of the power supply (battery). It is recommended to use a battery or other regulated power supply for the power supply. It is not recommended to use switching power supplies without filters (such as mobile phone chargers, mobile power supplies, and other switching power supplies),otherwise the interference generated by the power supply will affect the normal operation of this module. The normal working voltage of this module is 3.0-5.0V, and the power supply voltage should not exceed this range.

Antenna
The FM_ANT port is used to connect an FM antenna. In order to better receive FM signals, it is recommended to connect a 75cm-long whip antenna.

3: headphone/speaker output
This module comes with a 3WX2 channel audio power amplifier. If you need a speaker to connect to the speaker port, it is recommended to use a 4Ω/3W speaker. If the earphone is inserted, the audio is automatically switched to the earphone channel, and the speaker channel is automatically closed.

4:Volume adjustment
Turn the VOL encoder (the one on the right) to adjust the volume, and the LCD screen displays the volume level.

5:Frequency adjustment
Turn the FRE encoder (the one on the left) to adjust the receiving frequency, and the LCD screen displays the current frequency

6:Automatic channel search
Short press the FRE encoder, the local radio station will be searched automatically, and the LCD screen will display the current frequency. The search will stop when a valid radio station is found.

7:Mute
Short press the VOL knob down to switch mute/non-mute

8:Automatic squelch switch
Long press the VOL knob to switch on or off the auto squelch function, LCD display subtitles ON means to turn on the auto squelch, OFF means to turn off the auto squelch.

9:Automatic squelch threshold (threshold) adjustment (valid when the automatic squelch switch is turned on)
Long press the FRE knob down to enter the automatic squelch threshold adjustment interface. Rotate the VOL knob to adjust the automatic squelch threshold according to the specific usage. The adjustment range is 0-15. The larger the value, the higher the threshold and the weaker the signal. Easy to be muted. The opposite is true.

10: Connect to the serial port (no need to connect to serial port control)
The module reserves a TTL level serial port control interface. The communication between the TTL serial port and this module needs to be connected to the module's UART_RX, UART_TX and GND (the corresponding position on the PCB is marked),and the external MCU (microcontroller) or computer serial port can be used to send commands to control the module Features.    


Package Included:
1x Digital Stereo FM Radio Receiver Module (not contain cable)