Set up an ESP32 DevKit

The ESP32’s input is GPIO34 and its test signal is on GPIO25: a square wave at 1000 Hz. Its input accepts 0 V to 3.3 V.

The ESP32 reads sine waves best below 2 000 Hz and square waves below 1 000 Hz; what it reads at other speeds is in Accuracy and limits.

The same steps are in the scope’s Sketch window when you choose this board, with the sketch to copy or download.

Steps

1. Install the Arduino IDE, then open Boards Manager and install esp32 by Espressif Systems.
2. Copy the sketch from this window into a new sketch, or download it and open it.
3. Choose the board ESP32 Dev Module and its port, then press Upload. If the upload stalls at “Connecting”, hold the board’s BOOT button until it starts.
4. Close the IDE’s Serial Monitor if it is open.
5. Press Connect, and choose the ESP32 in the window the browser opens.

The ESP32’s ADC is most accurate between about 150 mV and 2450 mV with the setting this sketch uses, according to Espressif’s ADC documentation. Outside that range readings bend, so a signal that swings from 0 V to 3.3 V shows its bottom and top a little inside those values.