I2C Decibel Sound Level Meter Module

The PCB Artists decibel sound level meter module features

• High accuracy of ±1 dB SPL (Pro) and ±2 dB SPL (Regular and Spectrum Analyzer)
• No external microphone needed – contains built-in MEMS mic
• Measurement range of 30 dB to 120 dB
• Frequency Range of 30 Hz to 8 kHz
• Easy to use – standard I2C interface
• Low power consumption, suitable for battery powered use
• Selectable frequency response – A-weighted, C-weighted, Z-weighted
• Adjustable averaging time in the range of 10ms to 10,000 ms
  125ms (fast mode) and 1,000ms (slow mode) supported
• Threshold detection and interrupt
• 100-reading buffer to allow host MCU to sleep
• Stick to any surface using peel-off adhesive
• Low cost and small in size

Audio Spectrum Analyser

• 0 – 8 kHz readable into 64 bands (125 Hz each), and
• 0 – 8 kHz divided into 16 bands (500 Hz each)
• Energy in each band is readable in dB SPL

“PRO” Module – Professional sound meter features for your projects!

• 2 decimal precision, simultaneous A, C, and Z weighting
• True Integrating Noise measurements – Leq (A, C, Z weights)
• Noise Dosimeter to measure noise exposure by the second, minute or hour
• Octave band sound analysis

Sensor Module Selection Guide

Decibel Meter – Documentation

The I2C decibel meter module can be connected to any system with a 3.3V power output and I2C bus for communicating with the sound sensor module.

• Decibel Sensor – Interfacing Guide and Hardware Manual
• Decibel Sensor configuration examples – using sleep, interrupt and other features (coming soon)
• Decibel Sensor – Programming Guide and I2C Register Map (for “Regular” and “Spectrum Analyzer” modules)
• PRO Sensor I2C Register Map
• Mounting guide for SMD type decibel sensor module

Example Projects and Source Code

Here are some sample projects and source code to help you get started quickly with our decibel sensor module.

• Using the dB SPL sensor with Raspberry Pi, includes example source code in C
• ESP32 Decibel Logger Demo with ThingsBoard, includes ESP32 Arduino sketch
• RP2040 or Pi Pico Sound Level Sensor Demo, includes MicroPython code
• Decibel Meter with Arduino UNO and 7-Segment Display, includes Arduino sketch

Accessories

• IP67 protective membrane sticker, indoor and outdoor use

See the Module in Action

Watch How2Electronics’ YouTube video using an ESP32 devkit and OLED display to show decibel values acquired from our “Regular” sensor. At 0:40, you can see how the speaker’s properties and the module’s A-weighting affects decibel readings based on the sound frequency being measured.

• Using the decibel meter module with ESP32 + Ubidots

Physical Dimensions

Note that the bottom side of the module has no components to facilitate sticking the module to an enclosure using double-sided adhesive tape. The sound inlet port of the microphone is located on the bottom side.