An ESP32 dev board is a small programmable computer with WiFi built in, which you program from a PC over USB to read sensors, switch things and send data to your network. The ESP32-S2 Mini is a WiFi-only board built around the ESP32-S2FN4R2, with 4MB of flash and 2MB of PSRAM inside the chip, so there is room for bigger programs and MicroPython or CircuitPython scripts. Its USB-C socket connects straight to the chip, which means no driver to install and native USB that can act as a keyboard or MIDI device.
Use it for a WiFi temperature, humidity or door sensor reporting to Home Assistant, a USB macro pad or MIDI controller, learning MicroPython or CircuitPython, or upgrading a D1 Mini ESP8266 build that needs more memory and pins, since it uses the same footprint. It runs Arduino, MicroPython, CircuitPython and ESP-IDF. There is no Bluetooth, so if you need it as well as WiFi, the ESP32-S3 SuperMini or the ESP32-C3 SuperMini has both. The pins work at 3.3V, so a 5V sensor output needs a level shifter or a voltage divider. With all four header rows fitted the board does not sit in a breadboard, because each inner pin shares a breadboard strip with the outer pin beside it. Use female jumper wires on the pins, or fit only the two outer rows and it straddles a breadboard like any other board. Choose Unsoldered to fit the headers your way, or Pre-soldered to get all four rows fitted.
Specifications
Datasheets
What's in the box
USB-C cable not included.
Unsoldered: supplied loose. Solder them with the long pins pointing down from the underside, or fit only the two outer rows for a breadboard. Pre-soldered: all four strips fitted pointing down, soldered in New Zealand, ready for female jumper wires or a socket.
Wiring & getting started
- Plug in with a USB-C data cable
Plug the board straight into your computer. A charge-only cable powers it but no port appears.
- Select the board
In the Arduino IDE, install the esp32 board package by Espressif, choose ESP32S2 Dev Module (the S2 Mini entry in the list works too), set USB CDC On Boot to Enabled so the Serial Monitor works, and set PSRAM to Enabled to use the 2MB.
- Enter download mode for the first upload
Hold button 0, press and release RST, then release button 0 once the computer sees the board reconnect. Pick the port that appears. Do this again whenever no port shows up.
- Upload Blink and check it works
Open File > Examples > 01.Basics > Blink, change LED_BUILTIN to 15 and upload. The board stays in download mode until you press RST, so press it once the upload finishes. The blue LED next to the 15 marking then turns on and off every second, and the port may come back under a different name.
Note: Use one 5V source at a time. VBUS is joined straight to the USB-C socket, so an external supply on VBUS while USB-C is plugged in pushes current back into your computer.