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