Module FM Transmitter LCD_FM_TX_V2.2.1 PLL 87-108Mhz Pemancar Radio FM

Module FM Transmitter LCD_FM_TX_V2.2.1 PLL 87-108Mhz

1. Product Features:

1: Using advanced digital audio signal processing technology (DSP) and FM phase-locked loop modulation technology (PLL) to make the sound quality more realistic, the performance more stable, and the working frequency without deviation for a long time.
2: 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 button operation.
4: Automatically memorize the data before power failure
5: Automatic switching of multiple audio source inputs
6: Quartz crystal frequency stabilization is adopted, and the transmission frequency no longer drifts when the temperature changes
7: Support serial port command control

2. Product parameters:
Output power: 100mW
Audio frequency response range: 50Hz-18KHz
Transmitting frequency:
Turn off campus radio 87.0MHz-108.0MHz, turn on campus radio 76.0MHz-108.0MHz
Frequency adjustment step: 0.1MHz/time (short press of the button), 1.0MHz/time (long press of the button)
Modulation mode: Standard FM
Channel: LINE/USB channel (stereo), MIC channel (mono)
Equivalent noise: ≥30dB ( sound quality close to CD quality)
Supply voltage: DC 3.0V-5.0V
Working current: 35mA
Transmitting antenna: 75cm telescopic antenna
Transmission distance: FM transmitter module connected to a 75cm standard telescopic antenna, using a Tecsun PL-660 radio , the measured coverage radius in open space is 100 meters. (Note: The transmission distance is for reference only and may vary slightly depending on the operating environment)

3. Instructions for use:
<1>: Power supply
Connect the - and + pins on the module to the negative and positive terminals of the power supply (battery), respectively. A battery or other regulated power supply is recommended. Do not use an unfiltered switching power supply (such as a mobile phone charger or other low-quality switching power supplies), as this may interfere with the module's operation. The module's normal operating voltage is 3.0-5.0V; be careful not to exceed this range.

<2>：Button

Volume +/-: Short press for volume +/- 1, long press for 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 an FM antenna. To better transmit FM signals, it is recommended to connect an external 75cm telescopic antenna and keep the area around the antenna as free of obstacles as possible.

<4>: USB audio connection

If you need the USB audio broadcasting function of this module, you must also connect it to a computer via USB . USB ports are compatible with standard mobile phones, so you can use a mobile phone USB cable to connect the module to the computer. Since computer USB ports have a built-in 5V output, using a USB connection to the computer directly provides power to the module. Once connected to the computer's USB port, the module automatically enters PC audio broadcast mode. The LCD screen will display "PC". The computer will automatically install the driver and assign the module a sound card device named "CD002". Enable and enable this "CD002" audio device in your computer's sound settings. The computer system audio will then be transmitted via FM radio through this module. Tune a nearby radio to the same frequency as the module's transmission frequency to hear the computer system audio transmitted by this module.

<5>: LINE audio connection
If you need the module's LINE channel as an audio source, simply plug one end of the audio cable into the module's 3.5mm audio jack and the other end into your audio device (such as a phone's headphone jack). The module will then automatically switch to the LINE channel as the FM transmission source. A nearby FM radio can be tuned to the same frequency as the module's transmission to hear the audio from your phone.

<6>:FM wireless microphone
If you need the module's MIC as a sound source, simply unplug the LINE and USB cables (i.e., leave both LINE and USB unconnected). The module will automatically switch to the MIC channel as the FM sound source. This module comes with a high-sensitivity electret microphone, which can be used for wireless microphones, maternal and child monitoring, etc. When using it, pay attention to adjusting the module's transmission volume to achieve the best sound pickup effect.

<7>: Serial port control (do not worry about this part if you do not use the serial port control function)
The module has a reserved TTL-level serial control interface. To communicate with this module, connect the module's UART_RX, UART_TX, and GND pins. You can use an external MCU (microcontroller) or a computer serial port to send commands to control module functions. Note: Because computer serial port levels are not TTL, you will need to use an RS323-to-TTL converter or a USB-to-TTL serial port module to communicate with this module. Since serial command control requires computer expertise, those unfamiliar with this should avoid this. For all information, please refer to the product description. Customer service does not provide technical guidance in this area.

Serial port demonstration example and configuration:

Example: PC serial port assistant sends AT+FRE=875 (sets the receiving frequency to 87.5MHZ ), and the module returns the current frequency FRE=875 as shown below.

  Note: Due to data reduction, the decimal point is ignored in the frequency input and output.