2: The LCD display is more intuitive and accurate, with extremely low power consumption and minimal noise interference.

 

3: Built-in 30-level digital volume adjustment, which can be easily completed by key operation.

 

4: Automatically memorize the volume and frequency information before power failure

 

5: Automatic switching of multi-channel audio input

 

6: Adopt high-precision SMD quartz crystal to stabilize the frequency, the temperature and voltage change, the emission frequency no longer drifts

 

7: Support serial command control

 

  

Output power: 100mW

 

Audio frequency response range: 50Hz-18KHz

 

Turn off campus broadcasting 87.0MHz-108.0MHz, turn on campus broadcasting 76.0MHz-108.0MHz

 

Frequency adjustment step: 0.1MHz / time (short press of key), 1.0MHz / time (long press of key)

 

Modulation mode: standard FM frequency modulation

 

Channel: LINE / USB channel (stereo), MIC channel (mono)

 

Equivalent noise: ≥30dB (sound quality close to CD sound quality)

 

Power supply voltage: DC 3.0V-5.0V

 

Working current: 35mA

 

Transmitting antenna: 75cm whip antenna

 

Transmitting distance: The FM transmitting module is connected with a standard whip antenna of 75cm, and the radio uses Desheng PL-660, and the measured radius of the open field is 100 meters. (Note: The launch distance is for reference only, slightly different due to different use environments)

 

 

<1>: power supply

 

The corresponding ports of the module-, + are connected to the negative and positive poles of the power supply (battery) respectively. The power supply is recommended to use a battery or transformer step-down regulated power supply. Do not use switching power supply without filter (such as mobile phone charger, power bank, switching DC-DC power supply), otherwise the high frequency 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.

 

<2>: Button

 

Volume +/-: short press volume +/- 1, long press continuous +/-
Frequency +/-: short press frequency +/- 0.1MHz, long press continuous +/- 1MHz
Mute: Short press to switch between mute / unmute

 

<3>: antenna

 

The ANT port is used to connect the FM antenna. In order to better transmit FM signals, it is recommended to connect a whip antenna with a length of 75cm, and there should be no obstructions near the antenna as much as possible.

 

<4>: USB audio connection

 

If you need the USB audio broadcast function of this module, you also need to connect the USB cable to the computer. The USB port is compatible with ordinary mobile phones, so you can use the mobile phone USB cable to connect the module and the computer. Since the USB of the computer comes with a 5V output, using the USB to connect the computer can directly use the USB port to provide power to the module. After connecting the computer USB, this module will automatically enter the PC audio broadcast mode, the LCD screen will display the PC, the driver will be automatically installed on the computer, and the sound card device named ''CD002'' for this module will be enabled in the computer sound settings and When this ''CD002'' audio device is enabled, the computer system audio can be transmitted by FM frequency modulation through this module, and the nearby radio frequency is adjusted to be consistent with the transmission frequency of this module to listen to the computer system audio emitted by this module.

 

<5>: LINE audio connection

 

If you need the LINE (line input) channel of this module as a sound source, just plug one end of the audio cable into the 3.5mm audio jack of this module and the other end into your audio device (such as a phone earphone jack), then the module Automatically switch to the LINE channel as the source of FM transmission. As long as the nearby FM radio is adjusted to be consistent with the transmission frequency of this module, you can hear the audio from the mobile phone.

 

<6>: FM wireless microphone

 

If you need the MIC of this module as a sound source, just unplug the LINE cable and USB cable (that is, LINE and USB are not connected), the module automatically switches to the MIC channel as the FM transmission sound source, this module comes with high sensitivity electret Body microphones can be applied to wireless microphones, maternal and child monitoring as needed. When using it, pay attention to adjust the emission volume of this module to achieve the best sound pickup effect.

 

<7>: serial port control (no need to control this part without serial port control function)

 

The module reserves a TTL level serial port control interface. Communication between the TTL serial port and this module requires connecting the module's UART_RX, UART_TX and GND. You can use an external MCU (single chip microcomputer) or computer serial port to send commands instead of the key control module.

 

 

 

1PCS Digital FM Transmitter Module DSP PLL Wireless Stereo Microphone Circuit Board 76-108MHz LCD Display

 

 

 

Press and hold the UP and DOWN radio buttons at the same time in the power off state to turn on the power. The display B1 indicates that the backlight is always on, and B0 indicates that the backlight is off for 20 seconds. (The factory default setting is 20 seconds delay off backlight).

 

 

Press and hold the VOL +, VOL- keys in the power off state. After power-on, the LCD displays C1 to open the campus broadcast. C0 means to close the campus broadcast frequency band. (The factory default setting is to close the campus broadcast frequency band).

 

 

There are two solder joints M and G on the back of the module. The short connection between the two points is for mono sound transmission, and the disconnection between the two points is for stereo sound transmission. (The factory default is stereo transmission.) Note: In the stereo system, it must be satisfied that the sound source input to the module is stereo and the radio is also stereo to achieve the stereo effect. (Don't take a single speaker (mono) radio or the audio signal input to the module as mono to say why there is no stereo effect !!!).

 

 

1: Please confirm that the power supply polarity and power supply voltage are correct, and then power on. Input voltage exceeding 5V or reverse connection of power supply positive and negative poles may cause permanent damage to the module.

 

2: When working, do not touch the back components of the module with your hands, so as not to affect the normal operation of the module.