FM Stereo Audio Transmitter Circuit Board Module Bluetooth Forwarding Distance 500m FM Station Digital Display Module

FM FM stereo audio transmitter circuit board Bluetooth forwarding distance 500M frequency frequency station module

feature of product

1: The use of advanced digital audio signal processing technology (DSP) and FM phase-locked loop modulation technology (PLL) makes the sound quality more realistic, the performance is more stable, and the long-term working frequency has no offset.

2: The LCD display is more intuitive and accurate.

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

5: Automatically memorize the frequency before the power failure.

6: Support serial AT command control.

7: The chip-type high-precision quartz crystal is used to stabilize the frequency, and the transmission frequency will not drift when the temperature and voltage change.

8: Support Bluetooth audio to FM transmission and line input audio to FM transmission.

product parameters

Output power: +22.5dbm (170mW)

Audio frequency response range: 20Hz-15KHz

Transmission frequency: 76.0MHz-108.0MHz

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

Modulation Mode: Standard FM FM

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

Supply voltage: DC 3.7V-5.0V

Working current: 150mA

Transmitting antenna: 75cm rod antenna

Transmission distance: The FM transmitter module is connected to a 75cm standard FM radio rod antenna, and the radio uses Desheng PL-660, and the measured signal in the open field covers a radius of 500 meters. (Note: The transmission distance is for reference only, and the coverage distance is slightly different due to the difference in the use environment and receiver sensitivity)

Button function and application description

(1): Function description of external buttons

Volume + key:

short press volume + 1,

Long press continuously +

volume button:

short press volume – 1,

Long press continuously-

Frequency+:

Short press frequency + 0.1MHz,

Long press +1MHz continuously

frequency-:

Short press frequency – 0.1MHz,

Long press continuously -1MHz

Mute/Mode toggle key

Short press to toggle mute/unmute

Press and hold to switch to select the line input audio transmission mode or the Bluetooth audio transmission mode (when switching to the line audio transmission mode, the screen does not display the Bluetooth icon, when switching to the Bluetooth audio transmission mode, the screen will display the Bluetooth icon, when the Bluetooth is not connected to the mobile phone, the Bluetooth icon flashes, and the Bluetooth icon flashes. After connecting to the phone successfully, the bluetooth icon will light up)

(2): Power supply description

The module adopts DC5V power supply, and it is recommended to use a linear regulated power supply that is rectified, filtered and stabilized by a transformer. Switching power supplies without filters (such as mobile phone chargers, power banks, switching DC-DC power supplies) cannot be used, otherwise the hi