In this paper, the development of a low-cost acoustic sensor is presented based on an import-substituting element base as a cheap alternative to professional sensors or analog sensors. An Arduino board, a microphone module, a microSD card module, and other modules were used. To improve the accuracy of the data taken from the microphone, it was calibrated using a reference noise meter, using a logarithmic smoothing method to calculate the sound level in decibels, and an equation was formulated for converting the obtained ADC values into decibels. The code of the program executed by the sensor was developed and sewn into the device. The data captured from the microphone are stored in a CSV file with the date and time of the captured data. © 2024 by the authors.