Digital FM stereo transmitter module with LCD display and UART control

Information about this module is generated with the help of AI. The description may be incomplete, inaccurate, or subject to change.
This digital FM stereo transmitter module is a complete solution for wireless stereo audio transmission over the FM band. It combines advanced Digital Signal Processing (DSP) with PLL frequency synthesis to provide stable frequency, reliable operation and good audio quality. The built-in LCD display shows the current transmission frequency and other settings, making the module easy to operate both manually and through external control.

The main controller is the JieLi AC21CMD90D-90, integrating DSP processing, FM modulation, LCD control, button scanning, UART communication and EEPROM management. The module features stereo audio input for left and right channels and supports automatic switching between multiple audio sources. Frequency and volume settings are automatically stored in EEPROM and restored after power loss.

The transmission frequency can be adjusted using the onboard buttons or through the TTL UART interface, making the module suitable for control from Arduino, ESP32, Raspberry Pi or other microcontrollers. The UART interface allows easy integration into custom electronic projects and automated systems.

The module operates from a 3.0 to 5.0 V DC supply and provides approximately 50 mW RF output power. When used with a recommended 75 cm antenna, the transmission range can reach approximately 100 meters in open areas under favorable conditions. A high precision crystal oscillator ensures excellent frequency stability during operation.

This FM transmitter module is suitable for experiments, laboratories, education, audio distribution, campus broadcasting, development projects and other applications requiring a compact digital FM stereo transmitter.

Facts.
Product type: Digital FM stereo transmitter module
Main IC: JieLi AC21CMD90D-90
Display: LCD
Signal processing: Digital DSP
Frequency synthesis: PLL
Modulation: Standard FM
Transmission frequency: 87.0-108.0 MHz
Campus mode: 76.0-108.0 MHz
Frequency step: 0.1 MHz short button press
Frequency step long press: 1.0 MHz
RF output power: Approximately 50 mW
Audio frequency range: 50 Hz-18 kHz
Signal to noise ratio: >=30 dB
Supply voltage: DC 3.0-5.0 V
Operating current: Approximately 35 mA
Audio input: Stereo left and right
Communication: TTL UART
Control: UART and push buttons
Memory function: Automatically stores frequency and volume
EPROM: 24C02
Crystal oscillator: 12.000 MHz
Automatic audio input switching: Yes
Antenna: Recommended 75 cm antenna
Transmission distance: Up to approximately 100 meters in open area
Applications: FM broadcasting, audio distribution, education, laboratories, development projects and experiments

Included.
1 pc module.

About the product.
Weight: approx 11 gram.
Contact us if you have questions at info@pchbutik.se
Article no: 3612
Remaining stock quantity can be found under the Product details tab.
In our range since: 2026-08-03AI generated text.

In Sweden, the use of FM transmitters is subject to radio transmission regulations. This module is intended for development, education, laboratory use, and experimental purposes. Operation within the FM broadcast band may require authorization from the Swedish Post and Telecom Authority (PTS), depending on how and where the module is used. The user is responsible for ensuring compliance with all applicable laws and regulations before operating this module.

For you.
Components and building materials for those who build electronics themselves experiment and develop.