DIY ESP32 Oscilloscope

The DIY ESP32 Oscilloscope functions by sampling analog electrical signals through one of the ESP32 microcontroller's internal Analog-to-Digital Converter (ADC) pins. To protect the microcontroller and scale the input appropriately, incoming signals pass through a front-end voltage divider circuit constructed from a 100K resistor and a 10K resistor, alongside a 100nF ceramic capacitor that helps filter out high-frequency noise. Once the analog voltage is digitized by the ESP32, the microcontroller processes the data stream into waveform coordinate arrays. The user interacts with the system using six 6mm tactile switches and two SPDT switches to control settings such as timebase, trigger levels, and voltage scaling. Finally, the processed waveform and user interface menus are rendered graphically in real-time onto the compact 1.69-inch TFT display using the ST7789s driver. The entire system is assembled neatly on a custom copper clad PCB or perfboard, bringing together processing, user controls, and visual feedback into a single handheld testing instrument.

Used by hobbyists, students, and engineers for low-frequency signal analysis, audio waveform testing, sensor output debugging, and educational electronics troubleshooting without purchasing expensive commercial lab equipment.