Android-Based Oscilloscope for Signal Acquisition and Visualization

Abstract

In this project, an ESP32–ADS1115 embedded hardware framework is used to design and implement a wired and wireless signal acquisition system with real-time visualisation on an Android-based oscilloscope. The ADS1115, a 16-bit precision analog-todigital converter, interfaces with the ESP32 via wired I²C communication to acquire low-frequency analogue signals with enhanced resolution and accuracy. The ESP32 microcontroller is integrated into the system for high-speed data processing and wireless communication. Signal data is either wirelessly transferred to an Android device via Wi-Fi or Bluetooth or recorded via wired inputs. The Termux-X11 environment is used to process and visualise the received data, allowing for oscilloscope-like functionality and timedomain waveform display on a portable platform. The suggested framework is appropriate for field measurement, laboratory, and educational settings since it provides a small, affordable, and power-efficient substitute for traditional oscilloscopes. The effectiveness of the suggested embedded system for portable signal analysis is validated by experimental results showing accurate waveform rendering, dependable signal acquisition, and stable wireless communication.

Introduction

This text presents the design and development of a portable Android-based oscilloscope that uses an ESP32 microcontroller, an ADS1115 high-resolution ADC, and an Android smartphone for real-time signal acquisition and visualization. Traditional oscilloscopes are essential for observing and analyzing electrical signals but are often expensive, bulky, and inaccessible for students, educators, and field engineers.

The proposed system addresses these limitations by combining the wireless communication capabilities of the ESP32 with the high-precision analog-to-digital conversion of the ADS1115. While the ESP32's built-in ADC has limited accuracy, the ADS1115 provides 16-bit resolution, programmable gain amplification, and reliable signal digitization through I²C communication.

The system leverages Android smartphones as display and processing platforms. Using the Termux environment and Termux X11, users can run Python programs and visualize waveforms in real time without requiring specialized oscilloscope hardware or custom Android applications. This transforms a smartphone into a portable oscilloscope capable of signal monitoring and analysis.

Literature Review

Previous research has focused on:

• PC-based oscilloscopes to reduce cost and complexity.
• Microcontroller-based oscilloscopes using platforms such as Arduino.
• Smartphone-based visualization systems for improved portability.
• Wireless and IoT-enabled oscilloscopes for remote monitoring.
• Software-defined and virtual oscilloscopes with advanced signal-processing features.

These developments demonstrate a trend toward affordable, portable, and software-driven measurement systems.

Methodology

The proposed system operates through the following stages:

1. Analog signals are collected using input probes.
2. Signals undergo conditioning through filtering, amplification, attenuation, and voltage scaling.
3. The ADS1115 converts the conditioned analog signals into high-resolution digital data.
4. The ESP32 processes and buffers the data.
5. Digital data is transmitted wirelessly via Bluetooth to an Android smartphone.
6. The smartphone receives, processes, scales, and displays waveforms in real time using Termux and Python-based plotting tools.
7. System performance is evaluated based on accuracy, latency, and stability.

System Architecture

The system consists of:

• Analog signal source
• Signal conditioning circuit
• ADS1115 ADC
• ESP32 microcontroller
• Android smartphone

The ESP32 handles data acquisition and wireless transmission, while the Android device provides waveform visualization and analysis.

Advantages

• Low cost compared to commercial oscilloscopes.
• Portable and lightweight design.
• High measurement resolution through the ADS1115.
• Wireless communication capability.
• Real-time waveform display on smartphones.
• Suitable for education, embedded systems development, laboratory experiments, and field signal monitoring.

References

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Copyright

Copyright © 2026 Chintham Likitha, Desetti Srinivasa Rao, Yeshwanth Botsa, Bora Naidu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.