MCU Dev Kits & Boards

The boards you actually buy when prototyping. For the silicon underneath see MCU Platforms; for the bare modules to drop into your own PCB see MCU Modules; for build tooling see Arduino & PlatformIO.

Espressif reference dev kits

Espressif's own reference boards. The dependable, if dull, choice — well-documented, widely supported, cheap.

• ★ ESP32-DevKitC-V4 — the classic ESP32-WROOM-32 reference board; USB-UART, breadboard-friendly. Still ships, still works, ~$5.
• ★ ESP32-S3-DevKitC-1 / -DevKitM-1 — the modern equivalent for the S3. C-1 has dual USB-C; M-1 is the smaller WROOM-1U-MINI variant.
• ESP32-C3-DevKitC-02 / -DevKitM-1 — minimal C3 reference board.
• ESP32-C6-DevKitC-1 / -DevKitM-1 — the Matter / Thread / Zigbee reference; pick this for 802.15.4 work.
• ESP32-H2-DevKitM-1 — Thread/Zigbee endpoint reference (no Wi-Fi).
• ESP32-P4 Function-EV-Board — high-end reference with display + camera headers; pair with a C6 module for Wi-Fi.
• ESP32-S3-BOX-3 — Espressif's smart-display reference (3.5" screen + speaker + mic). Targets HMI and voice apps.

Adafruit Feather / QT Py / Trinkey

Adafruit boards lean expensive but ship with libraries, schematics, and CircuitPython tested out of the box. The "buy from a shop you trust" choice.

• ★ Feather ESP32-S3 — the modern flagship Feather; LiPo charging, USB-C, plenty of GPIO, STEMMA QT.
• Feather ESP32-S2 / ESP32 V2 — older Feathers; still sold.
• Feather RP2040 / RP2350 — Pi-silicon Feathers; no radio, but cheap and fast.
• Feather nRF52840 Express / Sense — BLE-first Feather; "Sense" adds onboard sensors (IMU, mic, env).
• Feather M0 / M4 Express — SAMD21 / SAMD51 Feathers; the original CircuitPython platform.
• Feather M4 CAN — SAME51 with CAN-FD onboard.
• QT Py / QT Py ESP32 / QT Py RP2040 / QT Py RP2350 — postage-stamp boards with USB-C and a STEMMA QT connector. Great for sensor breakouts.
• Trinkey — USB-stick form factor (RP2040 or SAMD21); for one-button macro pads / HID demos.
• Metro ESP32-S3 / RP2350 — Arduino-Uno-form-factor boards in Adafruit's house line.

SparkFun Thing Plus / RedBoard

Similar audience to Adafruit. SparkFun's "Thing Plus" is their Feather equivalent.

• Thing Plus ESP32-S3 / C6 / WROOM — Feather-pinout SparkFun boards.
• Thing Plus RP2040 / RP2350 — Pi-silicon Thing Plus.
• MicroMod — modular SparkFun spec; swap an MCU "processor card" into a carrier board.
• RedBoard Artemis — Apollo3 (Cortex-M4F at 48 MHz, ultra low power).

Seeed XIAO

Tiny (21 × 17 mm) modules with USB-C; fast-iterating lineup hits a "smallest decent dev board" sweet spot.

• ★ XIAO ESP32-C3 — $5-ish ESP32-C3 with USB-C and an external antenna pad. Very popular.
• ★ XIAO ESP32-S3 / S3 Sense — S3 in the same form factor; "Sense" adds a camera, mic, microSD.
• XIAO ESP32-C6 — Matter / Thread / Wi-Fi 6 in the XIAO form.
• XIAO RP2040 / RP2350 — Pi silicon in XIAO.
• XIAO nRF52840 / Sense — BLE in XIAO; "Sense" adds 6-DoF IMU + mic.
• XIAO MG24 — Silicon Labs Series 2 (BLE + Matter) in XIAO form.

Raspberry Pi Pico (RP2040 / RP2350)

The dominant cheap, USB-native, breadboard-friendly hobby platform.

• ★ Raspberry Pi Pico — RP2040, $4. The reference; sold by every shop.
• ★ Raspberry Pi Pico W — adds CYW43439 Wi-Fi 4 + BT 5.2; $6.
• ★ Raspberry Pi Pico 2 — RP2350, dual M33 or RISC-V Hazard3, $5. The 2026 default.
• ★ Raspberry Pi Pico 2 W — Pico 2 + radio; $7.
• Pimoroni Tiny 2040 / Tiny 2350 — credit-card-shaved RP variants.
• Cytron Maker Pi Pico — Pico carrier with breakouts (SD, audio, GPIO LEDs).
• WeAct RP2040 / RP2350 — cheap Chinese Pico clones with USB-C and more flash.

Wemos / WeMos / D1 Mini family

Small ESP boards in a roughly Adafruit-Feather-but-cheaper form factor. Original "D1 Mini" was ESP8266; lineage continues.

• D1 Mini (ESP8266) — the original; legendary cheap-and-cheerful. ~$3.
• D1 Mini ESP32 / S2 Mini / S3 Mini / C3 Mini — same footprint, modern silicon. Lots of shields available (relay, motor, OLED, NeoPixel, etc.).
• LOLIN line — Wemos's renamed branding (LOLIN D32, LOLIN S3 Pro, etc.).

M5Stack ecosystem

Stackable, plastic-cased ESP32 modules with screens / batteries / sensors. Less for prototyping a custom PCB; more for "I want a finished-looking gadget today."

• ★ M5Stack Core2 / CoreS3 — 2-inch IPS display, battery, speaker, IMU, microSD; ESP32 / ESP32-S3. The flagship.
• ★ M5Stack Atom / AtomS3 / AtomS3 Lite — tiny 24mm cube ESP32-S3; LCD or just LED.
• M5Stack StickC Plus 2 — wand-shaped ESP32 with a small color screen.
• M5Stack Cardputer — credit-card-sized ESP32-S3 device with a tiny QWERTY keyboard and screen; programmable handheld.
• M5Stack PaperS3 — e-paper variant.
• M5Stack Module / Unit / Hat / Base ecosystem — accessory standards (PortA/B/C, Grove, M-Bus).

LilyGO T-series

LilyGO ships niche, fun, well-priced ESP boards with displays / e-paper / cell modems.

• LilyGO T-Display S3 — ESP32-S3 + 1.9" IPS LCD. The default "ESP32 with a small color screen."
• LilyGO T-Display S3 Pro — bigger 3.4" screen, capacitive touch.
• LilyGO T-Watch S3 — ESP32-S3 in a watch shell with touch + IMU + LoRa option.
• LilyGO T-Beam / T-Beam Supreme — ESP32 + LoRa + GPS; mesh-radio favorite. The de-facto Meshtastic node.
• LilyGO T-Echo — nRF52840 + LoRa + e-paper + GPS; long-life Meshtastic.
• LilyGO T-Deck / T-Deck Plus — ESP32-S3 handheld with QWERTY keyboard + display.
• LilyGO T-SIM7080G / T-Call — ESP32 + LTE-M / NB-IoT / 2G modem.

Heltec / TTGO LoRa boards

• Heltec WiFi LoRa 32 V3 — ESP32-S3 + SX1262 LoRa + OLED. Common LoRa / Meshtastic node.
• Heltec Wireless Stick / Stick Lite — small LoRa + ESP variant.
• Heltec CubeCell — ASR6502 SoC with LoRa for ultra-low-power LoRaWAN.

Teensy (PJRC)

US-made (Sherwood, OR), more expensive, but legendary for audio + USB.

• ★ Teensy 4.0 — i.MX RT1062 @ 600 MHz; the fast hobby MCU. ~$24.
• ★ Teensy 4.1 — same chip, more pins, native Ethernet PHY pads, microSD; ~$32.
• Teensy LC / 3.x — older, slower; 4.x is preferred.

Arduino's own boards

Arduino brand has refreshed its lineup; the new boards are competitive again.

• ★ Arduino UNO R4 WiFi — Renesas RA4M1 + ESP32-S3 (for radio). The "modern UNO."
• Arduino UNO R4 Minima — UNO R4 without the radio coprocessor.
• Arduino UNO R3 — the classic 8-bit ATmega328P; still sold for education.
• Arduino Nano ESP32 — ESP32-S3 in a Nano form factor. Excellent value.
• Arduino Nano RP2040 Connect — RP2040 + WiFi/BT + IMU.
• Arduino Nano 33 BLE Sense Rev 2 — nRF52840 + IMU + mic + env sensors.
• Arduino Portenta H7 / Portenta C33 / Portenta X8 — high-end Arduino "industrial" boards (STM32H7 / Renesas / i.MX 8M Mini).
• Arduino GIGA R1 WiFi — STM32H747 dual-core; high-pin-count board with display option.
• Arduino MKR family — older, MKR1000 / MKR WiFi 1010 etc.; mostly maintenance mode.

STM32 dev boards

• ★ STM32 Nucleo-64 / -144 — official ST dev boards; one per chip family (Nucleo-F401RE, Nucleo-H743ZI, etc.). Cheap, well-documented, ST-LINK on board.
• ★ STM32 Discovery — ST's "evaluation" tier; usually adds a screen / sensors.
• Black Pill (STM32F411 / F401) — $3 Chinese clone; USB-C, popular hobbyist board.
• Blue Pill (STM32F103) — older $2 hobbyist board; clones are dubious quality.
• WeAct H743 / G431 / F411 — better-built Chinese STM32 boards.

Nordic nRF dev kits

• nRF52840 DK — official Nordic dev kit; supports Zephyr / nRF Connect SDK out of the box.
• nRF5340 DK — current-flagship dev kit; dual-core BLE.
• nRF54L15 DK / nRF54H20 DK — newer-gen dev kits.
• nRF9151 DK / Thingy:91 X — cellular IoT dev kits.
• Nordic Thingy:53 / Thingy:91 — sensor-loaded, battery-equipped enclosed dev gadgets.

Boards aimed at hardware hackers

• Flipper Zero — multi-tool with sub-GHz radio, RFID, NFC, IR, GPIO; STM32WB55. Open firmware. The "hacker tamagotchi."
• HackRF One — software-defined radio (SDR), not strictly an MCU board but hangs out with them.
• Bus Pirate 5 / 6 — RP2040-based protocol hacking probe.

Pick this if…

• Default cheap ESP-S3 board, breadboard-friendly: ESP32-S3-DevKitC-1 or Seeed XIAO ESP32-S3.
• Default cheap RP2040/2350 board: Raspberry Pi Pico 2 (W).
• Default BLE dev kit: nRF52840 DK (or Adafruit Feather nRF52840 if you want LiPo).
• You want a finished-feeling gadget without designing an enclosure: M5Stack Core2 / Cardputer.
• Smartwatch / wearable ESP32: LilyGO T-Watch S3.
• Meshtastic node: LilyGO T-Beam Supreme or Heltec WiFi LoRa 32 V3.
• Audio / MIDI / fast USB: Teensy 4.0 or 4.1.
• Modern Arduino-shape board: Arduino UNO R4 WiFi or Arduino Nano ESP32.
• Tiny postage-stamp dev board: Seeed XIAO (any flavor).
• STM32 evaluation: ST Nucleo for the chip family you're targeting.