ESP32

The ESP32 is a microcontroller — that is, a tiny computer on a single chip — developed by the Chinese company Espressif Systems and launched in 2016. Unlike an ordinary processor, which needs an operating system and memory on separate components, the ESP32 combines a processing unit, working memory, and radio modules on just a few square millimeters. It can transmit via Wi-Fi and Bluetooth at the same time. What makes it special: the module often retails for less than three euros. That makes it cheaper than many of the cable connectors soldered to it.

ESP32 as a driving force of the Internet of Things

The Internet of Things — IoT for short — refers to the idea of connecting everyday objects to the internet. A heater that regulates itself. A mailbox that sends a message when mail is dropped off. A sensor in a field that reports soil moisture. All of this requires a chip that is small, cheap, and capable of wireless communication.

This is exactly the gap the ESP32 fills. Before it, there were either chips that could communicate wirelessly but were expensive, or cheap chips without wireless capability. The ESP32 was one of the first solutions to offer both at once — and in doing so sparked an entire maker movement of hobbyists and startups. Today it is found in millions of products worldwide, from industrial sensors to do-it-yourself weather stations.

Design and programming of the chip

Inside the ESP32, the standard version runs two processing cores that can handle different tasks simultaneously. One, for example, can wait for sensor data while the other maintains a Wi-Fi connection. In addition, there are digital inputs and outputs — so-called GPIO pins — used to connect components such as LEDs, temperature sensors, or motors.

The chip is usually programmed in C++ or, for beginners, with a simplified version of Python called MicroPython. The Arduino IDE development environment, familiar to many from school lessons, also supports the ESP32. You write the code on a regular computer, transfer it to the chip via USB cable — and the program then runs permanently on the ESP32, without needing a computer running alongside it.

An important difference from a Raspberry Pi, which one might easily confuse with the ESP32: the Raspberry Pi is a complete mini computer running an operating system like Linux. The ESP32 has no operating system. It runs a single program directly — which makes it faster to start up and more power-efficient, but also less flexible.

ESP32 in products, projects, and the news

In everyday life, people often encounter the ESP32 without realizing it. Smart plugs, inexpensive fitness trackers, video doorbells, or air-quality sensors in schools and offices — many of these devices run on an ESP32 or one of its successors from the same family, such as the ESP32-S3 or the ESP32-C3. The well-known Shelly thermostat, widely used in home automation, was also long based on ESP chips.

The ESP32 tends to show up in tech media mainly in connection with security vulnerabilities: because the chip is so widespread, a discovered flaw can potentially affect millions of devices at once. In early 2025, one such report caused a stir when researchers showed that a vulnerability in the chip’s Bluetooth stack could be exploited to take over other devices. This illustrates that the more often a chip is used, the more important its security becomes.

For beginners, the ESP32 is a popular entry point into electronics and programming, since learning materials are abundant and development boards — ready-made circuit boards with the chip mounted on them — are available for just a few euros. Many schools and universities deliberately use it in their teaching.