【2024 DigiKey Creative Competition】Conference Sound Source Tracker

左手阿飞 · Published on 2024-10-31 19:38

【2024 DigiKey Creative Competition】Conference Sound Source Tracker [Copy link]

Conference sound source tracker

Author: Left-handed Afei

Introduction

With the development of online live broadcast technology, many offline activities have moved online, such as online meetings, online classes, etc. In order to further improve the sound quality of online meetings or online classes, this design proposes a conference sound source tracking system with the following main functions:

1. Localize the sound source and identify the direction of the sound;

2. Sound source tracking, use a stepper motor to control the direction of the microphone, track the sound source, and reduce interference noise; (unfinished)

3. Detect the meeting room environment and upload it to the cloud to remind staff to turn on air conditioners and other equipment in advance.

Figure 1 Photo of the work

The materials used and their intended uses are as follows:

1. Sipeed microphone array (MIC_ARRAY): used for sound collection;

2. K210 development board: used for sound data analysis, identifying sound direction, and sending corresponding data to STM32F411;

3. STM32F411 development board: receives K210 data and controls the stepper motor to change the direction of the microphone array so that the front of the microphone corresponds to the sound source;

4. SGP30 & DHT11: SGP30 is an air quality sensor that can detect the content of volatile organic compounds (TVOC) and CO2 in the air; DHT11 is a temperature and humidity sensor that can detect temperature and humidity;

5. ESP32S3 development board: Upload the detected air quality (TVOC, CO2, temperature and humidity) data to the cloud (Alibaba Cloud), view it through the mobile phone APP, and turn on the air conditioner and other equipment in advance before the meeting starts.

2. System Block Diagram

The hardware design includes the hardware design block diagram as shown in Figure 2:

Figure 2 System Block Diagram

The sound source direction detection part is completed by the microphone array and K210 card. The microphone direction is controlled by the STM32 to control the two stepper motors. The two stepper motors adjust the X-axis direction and the Y-axis direction respectively. The air quality detection part is detected by the sensors SGP30 and DHT11, and uploaded to Alibaba Cloud through ESP32 connected to WIFI to achieve remote detection and control.

3. Functional description of each part

The first part is the sound source direction detection part, which is completed by the microphone array and K210 card.

Figure 3 Sound source direction detection

The microphone array is manufactured by sipeed, and consists of 6+1 microphones, 6 evenly distributed around the circumference and 1 in the center. The transmission method is I2S transmission, which can detect the sound intensity in different directions. There are 12 serial LEDs on the circumference to display the direction of the sound source. The LED control method is serial digital control, and the serial control protocol is similar to SPI.

The K210 development board is rich in resources, with a built-in LCD screen (480*320) and a microphone array interface, which can be directly connected to the microphone array. The development language is microPython. MicroPython is easy to develop, and there are a lot of third-party libraries available for use, which is convenient for development.

K210 receives the sound data detected by the microphone array, calculates the direction and distance of the sound source by the data difference of the six microphones, controls the LED to display the corresponding direction, and sends the data to STM32F411 through the serial port.

The second part is the direction control part, which consists of STM32F411 and 2 stepper motors.

Figure 4 Microphone direction control

STM32 receives sound direction data through the serial port and controls two stepper motors. The two stepper motors control the movement in the x-axis and y-axis directions respectively, so that the microphone array faces the direction of the sound source to achieve the purpose of sound noise reduction.

The third part is the conference room environment detection part, which consists of SPG30, DHT11 and ESP32S3.

Figure 5 Meeting room air quality detection

SPG30 can detect the concentration of TVOC and CO2 in the air. It is transmitted through the I2C communication protocol. The transmission data format is 6 bytes per group. The first three bytes transmit TVOC concentration, and the last three bytes transmit CO2 concentration. Each group of data has two bytes as data bytes (16 bits) and the third byte as CRC check bit.

DHT11 is a temperature and humidity detection sensor, which is transmitted through a single bus protocol. Each frame of data is 5 bytes, the first 2 bytes are humidity data, the next 2 bytes are temperature data, and the last byte is a check bit.

ESP32S3 receives the air quality data detected by SPG30 and DHT11 and uploads it to Alibaba Cloud. It can be viewed on Alibaba Cloud and mobile APP. A switch is set on the APP to remotely control an LED. In actual applications, the LED can be replaced by air conditioners, fresh air fans, air purifiers and other equipment. If necessary, additional switches can be added to control more equipment.

4. Source Code

https://download.eeworld.com.cn/detail/%E5%B7%A6%E6%89%8B%E9%98%BF%E9%A3%9E/634860

5. Demonstration video of the work’s functions

6. Project Summary

This is my first time to participate in the innovative design competition hosted by Digi-Key. After practicing in this competition, I have a deeper understanding of embedded development. Thank you Digi-Key for providing this rare opportunity.

This design completed a conference sound source tracker. The device can complete functions such as conference room sound source direction tracking, air environment detection, and air quality improvement. Due to the tight time, the selected solution is the one with the shortest development time and the easiest to implement, but there are some problems. The biggest problem is that the cost is too high. A total of three controllers are used: K210, STM32, and ESP32. The controller functions are repeated, and the cost reduction can be considered in the future, using the ESP32+STM32 solution or using one of the controller solutions alone. Secondly, the solutions mostly use library functions, and the underlying research is not in-depth enough, and the equipment operation efficiency is low. In the future, you can try to develop from the bottom to improve your manual reading and development capabilities.

In short, after this training, my embedded development skills have been greatly improved, which has broadened my horizons and provided me with more ideas for subsequent work. Thanks again to Digi-Key for providing the opportunity, and I wish the competition will get better and better!!!

Unboxing post: https://en.eeworld.com/bbs/thread-1294810-1-1.html

Temperature and humidity detection: https://en.eeworld.com/bbs/thread-1296460-1-1.html

TVOC and CO2 detection: https://en.eeworld.com/bbs/thread-1294810-1-1.html

【2024 DigiKey创意大赛】会议声源追踪器.doc (12.92 MB, downloads: 0)