Qwiic FM Transceiver - Si4721
The Qwiic FM Transceiver breakout board features the Silicon Labs Si4721, which integrates both FM broadcast reception and low-power FM stereo transmission into a single IC. It can tune FM stations for listening and transmit audio on the FM band — all controllable over I2C via Qwiic connectors.
In addition to stereo audio, the Si4721 supports RDS/RBDS for transmitting and receiving text data on the FM band — the same technology commercial stations use for call signs and song titles. The board includes a 3.5 mm line-in jack for audio input, a 3.5 mm headphone output with onboard TPA6111 headphone amplifier, and a poke-home connector for antenna attachment.
Key Features
- Silicon Labs Si4721 – Combined FM receiver and transmitter
- FM Stereo Transmission – Low-power, standards-compliant broadcast
- FM Reception – Full FM band tuner
- RDS/RBDS Support – Send and receive text data over FM
- 3.5 mm Line-In – Audio input jack for transmission
- 3.5 mm Headphone Out – TPA6111 headphone amplifier
- I2C Interface – Qwiic connectors, address configurable (0x11 or 0x63)
- Antenna Connector – Two-position poke-home terminal
- Reliable Range – Approximately 10–20 metres
Ideal For
- FM radio projects and experimentation
- Wireless audio streaming over short distances
- Broadcasting sensor data or text via RDS
- Intercom and local broadcast applications
Note: This is an extremely low-power transmitter designed for unlicensed use in most regions. However, you are responsible for complying with local RF transmission regulations. Always check your local laws before transmitting.
The Qwiic FM Transceiver - Si4721 appears in the following collections:
SKU SF-SPX-15853
by Little Bird
