NXP RT685 Audio Weaver / TalkTo

Leverage the dual-core architecture of an RT685 processor to run DSP Concepts’ Alexa far-field qualified TalkTo audio front-end on the HiFi4 DSP core and playback processing on the Cortex-M33 core for high performance voice-enabled smart speakers and sound bars. This full-featured design, with its built-in support for multiple USB audio modes including recording, streaming and playback processing, is extendable to support conference calling on USB cameras and speaker phones.


  • 6m+ Far-field voice activation range
    • DSP Concepts high performance TalkTo Audio Front-end 
  • Seamlessly integrate Alexa to your product 
    • High performance 4 mic TalkTo for far-field voice pickup
    • AVS qualified TalkTo with production ready algorithms
    • 4 mic pre-processing on HiFi4 core
  • Support for multiple USB audio modes
    • High fidelity USB Audio streaming with multiple USB audio modes for recording, streaming and playback
  • Made for multi-core applications
    • Audio Weaver running on Arm® Cortex®-M33 and Cadence® Tensilica® HiFi 4 DSP processor core for multi-core applications 
    • Playback processing and audio I/O on M33

Audio Front-end Features

  • DSP Concepts’ TalkTo for excellent far-field performance in noisy environments
    • 4 mic Beamformer with Single Channel Noise Reduction
    • State-of-the-art noise cancellation with Adaptive Interference Canceller (AIC) 
      • No reference signal needed
      • Eliminates 25 dB of external noise sources such as background music or a booming movie
    • 30+ dB Acoustic Echo Cancellation (AEC) for excellent music barge-in
  • Stereo Audio Playback processing running on Cortex-M33
  • Support for multiple audio modes
  • USB recording of raw and processed mic signals from external mic board
  • USB streaming of mic signals into offline ASR
  • USB streaming of music from PC through speaker playback processing
  • Line input audio for speaker playback processing
  • Playback audio through line out to drive a powered speaker

Software Integrations

  • Audio Weaver running on Cortex-M33 and HiFi 4 core
  • Audio Weaver Designer Standard - Drag-and-drop Graphical Tool to customize & tune audio -processing models in real-time with 500+ modules
  • Audio Weaver Core - Embedded audio-processing engine for Cortex-M33 and HiFi4 DSP
  • TalkTo, DSP Concepts’ high-performance audio front-end for state-of-the-art far-field voice control performance
  • Playback processing algorithms
  • Sensory TrulyHandsfree ‘Alexa’ wake word engine

Hardware Specifications

  • Processor
    • i.MX RT685 Cortex-M33 core processor with Cadence Tensilica HiFi 4 DSP
  • Memory
    • 64 MB Macronix Octal SPI Flash operating at 1.8 V
    • 8 MB Apmemory PSRAM
    • Full size SD card slot (SDIO)
  • Audio I/O
    • Stereo audio codec with line in/out and electret microphone
    • Stereo NXP TFA9894 digital amplifiers, with option for external +5V power for higher performance speakers
    • Support for up to eight off-board digital microphones via 12-pin header
    • Two on-board DMICS 
  • USB Connectivity
    • Onboard, high-speed USB, Link2 debug probe with CMSIS-DAP protocol (supporting Cortex M33 debug only) 
    • High speed USB port with micro A/B connector for the host or device functionality
    • UART, I2C and SPI port bridging from i.MX RT685 target to USB via the on-board debug probe

Included with the demo kit:

  • NXP RT685 Evaluation kit 
  • DSP Concepts 4 mic square and Trillium microphone array board
  • Voice UI Quickstart Bundle: Everything you need to know to design voice-enabled IoT products, including design guidelines, microphone placement, an Audio Weaver Designer layout (.AWD), and tools to get started.
  • USB cables

Ready to get started?

Schedule time to speak with one of our audio experts.