Implementação de um pedal de overdrive com controle gestual aplicado à guitarra elétrica

Abstract

There is variety of effect pedals for electric guitar applications, on the other hand, the interactivity features for musicians are limited, i.e., it is normally restricted to mechanical actuation via switches or fixed expression pedals. This work aims to develop an analog overdrive pedal prototype based on the topology of the classic commercial model Tube Screamer TS808. This circuit: i) distorts the electric signal from an electric guitar; ii) operates ideally in the frequency range from 200 Hz to 2 kHz; and iii) adjusts tone and gain (drive) parameters. The proposed innovation of this work consists of a dynamic control system that enhances musical expressiveness, using the instrument’s inclination (monitored by an Inertial Measurement Unit- IMU) to modulate the gain in real-time. The system employs an ESP32 microcontroller (to be attached to the guitar) that transmits the instantaneous angle to a receiver (located in the pedal), which adjusts the analog circuit through a resistive optocoupler (LED-LDR), preserving the signal integrity. The main findings demonstrate a proportional variation of the sound effect in response to the sensor movement, equivalent to a resistive variation of 13 kΩ to 500 kΩ in the drive control. It is possible to conclude that the hybrid approach (analog-digital) may enrich the musical performance and has successfully integrated the domains of embedded electronics and analog audio processing, proving to be a functional and feseable alternative for electric guitar players.