Product Introduction
The WTK6900HC is an identification module for local voice trigger engines. This Voice recognition module is based on the most advanced deep neural network (DNN-HMM) speech recognition technology, achieving high recognition rates, high real-time performance, integration of local and cloud capabilities, and highly integrated voice recognition and processing functions; it can realize semantic recognition and other specific intelligent voice interaction effects. Additionally, the module has the control and computing capabilities of a conventional MCU, enabling various applications requiring communication and control. In terms of application, the module supports local voice detection and wake-up, offline far-field recognition up to 3-5 meters, and 300 offline command entries. The module can push commands to the existing host device via UART, implementing a simple voice interaction interface. The module supports Chinese and English and can be widely used in home appliances, lighting, toys, wearable devices, industrial, automotive products, among others, to achieve voice interaction and control as well as various intelligent voice solutions.
Module characteristics
Kernel and Storage
• CPU clock speed up to 240 MHz, supports hardware floating-point operations
• Built-in 1 MByte SPI Flash memory
AI Algorithms
• Offline voice recognition using the latest neural network algorithms, offering high accuracy and low error rates, reliable recognition at distances up to 5 meters
• Voice noise reduction algorithm: filters out steady-state noise and effectively suppresses dynamic noise, ensuring accurate recognition even in noisy environments
• Audio decoding: supports MP3, WAV audio decoding
Audio
• Single-channel 16-bit DAC, SNR ≥ 95 dB
• Single-channel 16-bit ADC, SNR ≥ 90 dB
• Sampling rate supports 8 kHz / 11.025 kHz / 16 kHz / 22.05 kHz / 24 kHz / 32 kHz / 44.1 kHz / 48 kHz
• DAC supports direct drive output
Power Supply
• VCC ranges from 3.3V to 5.5V
• VOUT ranges from 2.2V to 3.4V
Bluetooth
• Compliant with Bluetooth V5.1 + BR + EDR + BLE specifications
• Meets transmission power consumption requirements for Class 1, Class 2, and Class 3
• Supports GFSK and π/4 DQPSK modulation types
• Provides +6 dBm transmission power
• Receiver sensitivity of -90 dBm
• Fast AGC enhances dynamic range
• Supports A2DP, AVCTP, AVDTP, AVRCP, HFP, SPP, SMP, ATT, GAP, GATT, RFCOMM, SDP, 12CA profiles
Peripherals
• Four multifunctional 16-bit timers, supporting capture and PWM modes
• Two 16-bit PWM driver generators
• One full-duplex basic UART
• One SPI interface supporting host and device modes
• External wake-up/interrupt on all GPIOs
Operating Temperature
• Operating temperature: -40°C to +85°C
• Storage temperature: -65°C to +150°C
Application Areas
• Smart home appliances (lifestyle appliances, health appliances, kitchen appliances, etc.)
• Smart bathroom, smart lighting, smart electromechanics, smart home
• Smart toys
Pin definition
module physical diagram
| Pin No | Signal name | Functional description |
| 1 | MIC+ | Connect the positive terminal of the microphone |
| 2 | MIC- | Connect the negative terminal of the microphone |
| 3 | SPK+ | The positive terminal of the speaker connection is properly aligned. |
| 4 | SPK- | The negative terminal of the speaker connection |
| 5 | WT8002 | Power amplifier chip |
| 6 | WTK6900HC-24SS | Voice recognition chip |
| 7 | Horn operation indicator light | The light turns red when it is not working and goes off when it is working. |
| 8 | Power indicator light | The green light is on when power supply is normal, and it goes off when there is no power supply. |
| 9 | VCC | Power input（3.3~5.5V） |
| 10 | GND | GND |
| 11 | TX | UART Asynchronous serial data output |
| 12 | RX | UART Asynchronous serial data input |
| 13 | Power supply port | TYPE-C power supply input（5V/1A/2A） |
WTK6900HC-24SS Physical pin description
WTK6900HC-24SS module encapsulation pin diagram
Circuit design reference
