This is a record of what progress we have made in the design of the sound monitoring sensor. We will review the methodology and the results from the tests we carried out and recommendations of what works best.
Resources
• Compilation of all Codes used is found here. • ESP32 , Raspberry pi, Arduino Uno, MAX4466, MAX9814, and SPH0645 Design requirements • record quality sound to SD CARD • measure dB SPL • Upload Measured dB SPL to Thingspeak/ Any cloud server • Upload recorded sound from SD CARD
Testing Analog Microphones MAX4466 and MAX9814 and Arduino Uno Connections:
SD Card Module Pin Arduino Uno pin CS 4 MISO 11 SCK 13 MOSI 12 GND GND VCC 5V
MAX4466 PIN CONFIGURATION OUT A1 VCC VCC GND 5V
MAX9814 PIN CONFICURATION OUT A1 GAIN 5V (40 dB gain) VCC 5V GND GND
Find Code here :
Results
• Able to measure dB SPL ranges from 46 – 76 dB SPL • We successfully recorded sound to SD card • Sound quality of MAX9814 is better than that of MAX4466
Using ESP32 Microcontroller
Using the ESp32, we tried to write I2S data signals from the SPH0645 microphone to the SD Card as well as measure dB SPL values.
The code used for testing is here.
Connection and Configuration SD Card Module ESP32 pin configuration CS 5 SCLK 18 MISO 19 MOSI 23 VCC VIN GND GND
SPH0645 PIN CONFIGURATION VCC 3.3V GND GND WS/ LRCLK 35 SD 33 SCK 32 SEL Not connected ( listen to Right Channel)
Results • Able to measure dB SPL 26 – 180 SPL • Failed to record sound to SD Card • ESP32 got overloaded with memory.
Using Raspberry Pi, Sound Card, and condenser microphone
with the Raspberry pi, we tried to achieve the design specifications of sound monitoring device
Configuration
Microphone via USB sound Card Raspberry pi USB 2.0 USB port
Results
• Recorded quality sound with the USB microphone • Uploaded dB SPL values to a server using Node red • Current dB range: 26 – 65 dB SPL