In the R&D and production of wireless audio devices and intelligent interactive terminals, the audio transmission capability and dual-mode compatibility of Bluetooth modules directly determine the core user experience of products. Fteasycom FSC-BT909 CSR Bluetooth Module, built on the Qualcomm CSR8811 chip, is a Bluetooth 4.2 dual-mode SoC module specially designed for Bluetooth audio applications. It features core advantages including a mature classic Bluetooth + BLE dual-mode architecture, professional audio transmitting and receiving capabilities, and comprehensive support for audio protocols.

 

Strong Dual-Mode Bluetooth Compatibility

The core advantage of FSC-BT909 lies in the integrated classic Bluetooth (BR/EDR) + Bluetooth Low Energy (Ble) dual-mode enabled by the Qualcomm CSR8811 wireless MCU, which supports the simultaneous operation of both modes. This design allows the module to be compatible with traditional Bluetooth audio devices and connect to the new generation of intelligent BLE terminals, completely breaking the interconnection barriers between different Bluetooth devices.

 

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The module fully supports multiple Bluetooth protocol versions including 4.2, 3.0, 2.1, 2.0, 1.2 I 1.1, enabling connection with billions of traditional Bluetooth speakers, earphones and in-vehicle audio-visual devices on the market. Tymczasem, it can realize data interaction and command linkage with BLE smart bracelets, central control panels and smart home terminals. In terms of protocol stack support, the module has been deeply optimized for audio scenarios and is also compatible with data protocols such as SPP, Gatt, PBAP and HID, achieving the dual functions of audio transmission and intelligent control. This allows devices to not only wirelessly transmit and receive high-definition audio, but also implement additional functions such as remote control and status synchronization, adapting to diversified intelligent audio application scenarios.

 

Audio Receiving and Transmitting

When used as an audio receiver, the module achieves high-speed and stable reception of Bluetooth audio streams through in-depth optimization of the Advanced Audio Distribution Profile (A2DP) and Audio/Video Remote Control Profile (Avrcp). External audio source devices (telefony komórkowe, computers, in-vehicle hosts) transmit stereo audio streams to devices equipped with this module (Głośniki Bluetooth, over-ear headphones, desktop audio systems) via the A2DP protocol. The module then transmits audio signals to the power amplifiers and sound units of the devices through professional PCM/I2S audio interfaces to complete audio decoding and playback. Naraz, users can realize remote control of the audio source device such as play/pause, previous/next track and volume adjustment through the physical buttons or touch terminals of the device via the AVRCP protocol, achieving an integrated experience of “receiving + control”. Ponadto, the module supports the Hands-Free Profile (HFP) for Bluetooth calls. When the receiving end is a Bluetooth earphone or in-vehicle Bluetooth speaker, it can realize audio reception for voice calls and microphone pickup feedback, meeting the dual needs of music playback and voice interaction.

 

When used as an audio transmitter, the module can convert analog/digital audio signals from traditional wired audio devices into Bluetooth audio streams, realizing the wireless upgrade of the devices. Wired speakers, TVs, in-vehicle audio-visual hosts, fitness equipment displays and other devices equipped with this module collect local audio signals through I2C/PCM interfaces. The module encodes the audio streams via the A2DP protocol and transmits them wirelessly via Bluetooth, which can be received by surrounding Bluetooth earphones, Bluetooth speakers and other devices, perfectly solving the pain point of no Bluetooth output in traditional devices. Na przykład, after a traditional TV is equipped with this module, it can directly transmit audio to Bluetooth earphones for silent movie watching; when installed on fitness equipment, it can transmit sports background music to users’ Bluetooth sports earphones, enhancing the user experience.

 

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With Bluetooth Class 1 high output power (18.5DBM) and high receiving sensitivity of -86dBm@0.1% BER, the module enables an audio transmission and receiving distance of up to 100 metry, and can still ensure stable transmission of audio streams in complex electromagnetic environments without disconnection, stuttering or delay. It also supports Bluetooth Enhanced Data Rate (EDR), and the 3Mbps transmission rate can guarantee lossless transmission of high-definition stereo audio, restoring the authentic sound quality.

 

Rich Hardware Interfaces

To meet the R&D and integration needs of different Bluetooth audio devices, FSC-BT909 has undergone comprehensive adaptive optimization in hardware design, balancing professionalism and flexibility, and can be quickly integrated into various devices without complex secondary development.

 

The module is equipped with professional data and audio interfaces such as UART, I2C and PCM/I2S. Wśród nich, PCM/I2S is a dedicated audio interface that can be directly connected to various audio decoding chips, power amplifier chips and microphone modules to achieve high-speed transmission of audio signals, eliminating the need for complex interface conversion design. The default baud rate of UART is 115200, which can be flexibly adjusted via AT commands.

 

Ponadto, the module is preloaded with a universal audio optimization firmware with underlying tuning for audio transmission and reception, enabling “plug-and-play” without the need for customers to conduct complex protocol stack development. It also supports in-depth customized development, allowing adjustments to audio decoding methods, Bluetooth pairing strategies, key function mapping and other parameters according to customer needs, greatly reducing the R&D cycle and development costs of audio devices.

 

Industrial-Grade Quality

FSC-BT909 is built to industrial-grade standards with excellent environmental adaptability and operational stability, meeting the commercial and civil production needs of various audio devices. It has passed international authoritative certifications, removing obstacles for product export.

 

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The module has an operating temperature range of -30℃ to +85℃, adapting to high and low temperature working environments. It can run stably in outdoor portable Bluetooth speakers, in-vehicle audio-visual devices, as well as indoor desktop audio systems and smart home audio terminals. Tymczasem, the module has obtained dual international certifications of FCC and CE, complying with international radio transmission standards, allowing products to be directly sold worldwide without additional certification tests by customers. It also strictly meets the RoHS environmental protection standards, conforming to the green production requirements of the modern electronic industry.