Also known as: ESP32
The ESP32 is a low-cost, dual-core microcontroller with built-in Wi-Fi and Bluetooth, often around a couple of dollars.1
Overview
That combination of price and wireless connectivity makes the ESP32 the workhorse of DIY smart-home gadgets and the Internet of Things. It comes from Espressif Systems in Shanghai, and common variants include the S3 and C3, alongside the older and simpler ESP8266 that preceded it.
Under the hood the classic ESP32 pairs two 32-bit cores with a few hundred kilobytes of SRAM and, crucially, a built-in 2.4 GHz radio doing both Wi-Fi and Bluetooth — the feature that separates it from a plain microcontroller. Newer parts swap the original Xtensa cores for RISC-V.
ESP32 versus its predecessor
The ESP8266 put a Wi-Fi microcontroller on the map; the ESP32 broadened it:
| Feature | ESP8266 | ESP32 (classic) |
|---|---|---|
| Cores | Single | Dual |
| Wireless | Wi-Fi | Wi-Fi + Bluetooth |
| GPIO | Few usable | Many, plus ADC/DAC/touch |
| SRAM | ~80 KB | ~520 KB |
| Role | Cheap Wi-Fi node | General wireless MCU |
Where it fits
You can program an ESP32 in C/C++ — using either Espressif’s ESP-IDF or the Arduino toolchain — or in MicroPython. Wired to sensors over its GPIO pins and talking over Wi-Fi, it is exactly the kind of cheap wireless node that crowds the airwaves GopherTrunk listens to, even though it is far too small to run GopherTrunk itself. As an SDR helper it makes a fine remote GPIO or telemetry board — reading a sensor and reporting over Wi-Fi beside a capture station.