Overview

This project demonstrates how to build a simple and affordable oscilloscope using an ESP32. It is designed for hobbyists, students, and electronics enthusiasts who want a portable tool for visualizing electrical signals without investing in expensive equipment.

The ESP32’s built-in ADC and processing power make it possible to capture, process, and display waveform data in real time. The output can be viewed on a display or streamed to a web interface.

Key Features

Real-time signal visualization

Compact and low-cost design

Uses ESP32’s internal ADC

Optional Wi-Fi-based waveform display

Suitable for basic signal debugging and learning

How It Works

The oscilloscope reads analog signals through the ESP32’s ADC pins. These signals are sampled at a defined rate and converted into digital values. The data is then processed and displayed either on a connected screen or through a browser interface.

Since the ESP32 ADC has voltage limits, an input conditioning circuit is used to scale and protect the input signal. This ensures safe operation and improves measurement reliability.

Hardware Components

ESP32 development board

Resistors for voltage divider

Capacitors for filtering

Optional OLED or TFT display

Breadboard or custom PCB

Connecting wires

Circuit Description

The input signal is first passed through a voltage divider to bring it within the safe ADC range of the ESP32. A capacitor may be added to reduce noise and stabilize readings.

The conditioned signal is then fed into one of the ESP32’s ADC pins. Proper grounding is essential to maintain signal accuracy and reduce interference.

Software Implementation

The ESP32 is programmed to continuously sample analog data at high speed. The firmware converts raw ADC values into meaningful voltage levels and formats them for display.

Depending on the setup, the waveform can be:

Rendered on a display module

Sent over the serial for plotting

Hosted on a web server for wireless access

PCB Design Option

For a cleaner and more reliable build, the circuit can be converted into a custom PCB. This improves signal integrity and makes the device more portable and durable.

When designing the PCB:

Keep analog paths short

Separate power and signal traces

Add proper grounding

Include test points for debugging

Applications

• Learning electronics and signal analysis
• Debugging simple circuits
• Visualizing sensor outputs
• Educational demonstrations

Limitations

• Limited sampling rate compared to professional oscilloscopes
• Restricted input voltage range
• Not suitable for high-frequency or high-precision measurements

Conclusion

This DIY ESP32 oscilloscope project is a great way to explore signal visualization using minimal hardware. It combines affordability, simplicity, and functionality, making it an excellent tool for beginners and makers. With further improvements like better ADC handling, buffering circuits, and optimized firmware, this project can be expanded into a more capable diagnostic tool. Explore a wide range of creative IoT and embedded builds with this collection of ESP32 projects with circuit diagrams and code for beginners and advanced makers alike.