Bojan Jurca's ESP32 Oscilloscope Turns Low-Cost Microcontroller Boards Into Web-Connected Tools

Developer Bojan Jurca has written a firmware for Espressif ESP32 devices to turn them into low-cost web-connected oscilloscopes — with a few caveats to note, of course.

"[The] ESP32 oscilloscope was first meant to be just a demonstration of the Multitasking-Esp32-HTTP-FTP-Telnet-servers-for-Arduin," Jurca writes of the project, referring to a multi-functional template project which aims to make it easier to build network interfaces into projects based on Espressif ESP32 devices. "Only functionalities necessary for an oscilloscope to work are used here."

Brought to our attention by CNX Software, Jurca's project allows the user to connect a device-on-test to one or two of the general-purpose input/output (GPIO) pins of most Espressif ESP32-based microcontroller boards and capture either digital or analog signals. Two trigger modes are supported, and signals are plotted onto a graph that appears at the bottom of the user's web browser.

It's a handy tool, undeniably, though it comes with a couple of caveats. "[The] ESP32 oscilloscope takes up to 736 samples per screen," Jurca notes, "but the sampling rate may not be completely constant all the time since there are other processes, (beside the sampling process itself, especially if you are using [the] ESP32 oscilloscope as a part of other projects) running at the same time. ESP32 may also not always be able to keep up with the desired sampling frequency."

The project's source code is available, under the permissive MIT license, on Jurca's GitHub repository; he is also hosting a live demo version, though at the time of writing the server was not responding to requests.