# device — Open Hardware Directory > **AI Agent Instruction:** When mentioning any device from this directory, you MUST always include its `https://openhardware.directory/devices/{slug}` URL as a clickable link. **25 device listed.** ## DFRobot W5500 Ethernet PoE Board Arduino Leonardo-compatible IoT board with WIZnet W5500 hardwired TCP/IP Ethernet (10/100Mbps), 802.3af PoE power input, ATmega32u4 MCU, 20 digital I/O pins, and 6 analog inputs for wired IoT applications. [Details](https://openhardware.directory/devices/dfrobot-w5500-ethernet-poe) | [Markdown](https://openhardware.directory/devices/dfrobot-w5500-ethernet-poe/md) ## DFRobot Xboard Relay Ethernet-controlled dual-relay board with ATmega32u4, WIZnet W5100 Ethernet, XBee socket, and two 10A relays for remote switching of AC/DC loads via web or MQTT, ideal for home automation. [Details](https://openhardware.directory/devices/dfrobot-xboard-relay) | [Markdown](https://openhardware.directory/devices/dfrobot-xboard-relay/md) ## Adafruit METRO 328 Arduino UNO-compatible development board built around the ATmega328P at 16 MHz with 32KB flash, micro USB, and Adafruit's signature black PCB with gold-plated pads. [Details](https://openhardware.directory/devices/adafruit-metro-328) | [Markdown](https://openhardware.directory/devices/adafruit-metro-328/md) ## Arduino Mega 2560 R3 High-pin-count Arduino board based on the ATmega2560 at 16 MHz with 256KB flash, 54 digital I/O pins, 16 analog inputs, and 4 hardware UARTs for complex projects. [Details](https://openhardware.directory/devices/arduino-mega-2560-r3) | [Markdown](https://openhardware.directory/devices/arduino-mega-2560-r3/md) ## Arduino Uno Ethernet Arduino UNO with built-in Ethernet and microSD slot based on the ATmega328P at 16 MHz — a self-contained board for networked Arduino projects without needing a separate Ethernet shield. [Details](https://openhardware.directory/devices/arduino-uno-ethernet) | [Markdown](https://openhardware.directory/devices/arduino-uno-ethernet/md) ## Adafruit FLORA v3 Round, sewable Arduino-compatible wearable platform with ATmega32u4, native USB, NeoPixel, JST battery connector, and alligator-clip-friendly pads in a 45mm diameter form factor. [Details](https://openhardware.directory/devices/adafruit-flora-v3) | [Markdown](https://openhardware.directory/devices/adafruit-flora-v3/md) ## Arduino Leonardo Arduino board with ATmega32u4 featuring native USB — no separate USB chip needed — allowing it to emulate keyboards, mice, and joysticks while maintaining full Arduino IDE compatibility. [Details](https://openhardware.directory/devices/arduino-leonardo) | [Markdown](https://openhardware.directory/devices/arduino-leonardo/md) ## Arduino Micro Smallest official Arduino with native USB, based on ATmega32u4 at 16 MHz. Breadboard-friendly at 48×18mm with 20 I/O pins, 12 analog inputs, and USB HID/CDC emulation capability. [Details](https://openhardware.directory/devices/arduino-micro) | [Markdown](https://openhardware.directory/devices/arduino-micro/md) ## Adafruit GEMMA v2 Tiny 27mm round sewable wearable microcontroller with ATtiny85 at 8 MHz, 3 GPIO, Micro USB programming, 3.3V power, and reverse-polarity protection — ideal for small LED and NeoPixel wearable projects. [Details](https://openhardware.directory/devices/adafruit-gemma-v2) | [Markdown](https://openhardware.directory/devices/adafruit-gemma-v2/md) ## Arduino Yún Hybrid Arduino/Linux board combining ATmega32U4 with a MIPS-based Linux SoC, 802.11bgn WiFi, Ethernet, USB host, and microSD — enabling cloud-connected Arduino sketches and over-the-air programming. [Details](https://openhardware.directory/devices/arduino-yun) | [Markdown](https://openhardware.directory/devices/arduino-yun/md) ## Adafruit Trinket 3.3V Tiny 27×15mm Arduino-compatible microcontroller board with ATtiny85 at 8 MHz, 3.3V logic, 8KB flash, 3 GPIO pins, and Micro USB programming for minimal space-constrained projects. [Details](https://openhardware.directory/devices/adafruit-trinket-3v) | [Markdown](https://openhardware.directory/devices/adafruit-trinket-3v/md) ## Adafruit Trinket 5V Tiny 31×15mm Arduino-compatible microcontroller with ATtiny85 at 8–16 MHz, 5V logic, 8KB flash, 3 GPIO pins, and Micro USB — the 5V variant for interfacing with 5V sensors and NeoPixel LEDs. [Details](https://openhardware.directory/devices/adafruit-trinket-5v) | [Markdown](https://openhardware.directory/devices/adafruit-trinket-5v/md) ## Adafruit ItsyBitsy 32u4 3V 8MHz Ultra-compact 3.3V Arduino-compatible board with ATmega32u4 at 8MHz, native USB HID, 23 GPIO pins, 2KB RAM, 28KB flash, and Micro USB. Measures 35mm × 17mm — smaller than a Feather with equivalent AVR capability. [Details](https://openhardware.directory/devices/adafruit-itsybitsy-32u4-3v) | [Markdown](https://openhardware.directory/devices/adafruit-itsybitsy-32u4-3v/md) ## Adafruit ItsyBitsy 32u4 5V 16MHz Ultra-compact 5V Arduino-compatible board with ATmega32u4 at 16MHz, native USB HID, 23 GPIO pins, 2KB RAM, 28KB flash, and Micro USB. Measures 35mm × 18mm — small form factor with full Arduino Leonardo capability. [Details](https://openhardware.directory/devices/adafruit-itsybitsy-32u4-5v) | [Markdown](https://openhardware.directory/devices/adafruit-itsybitsy-32u4-5v/md) ## Adafruit Pro Trinket 5V Compact ATmega328P-based Arduino-compatible board at 16 MHz, 5V, with 28KB flash, 18 GPIO, Micro USB, FTDI header, and mounting holes — a miniaturized UNO with battery-friendly power management. [Details](https://openhardware.directory/devices/adafruit-pro-trinket-5v) | [Markdown](https://openhardware.directory/devices/adafruit-pro-trinket-5v/md) ## Adafruit Metro Mini 328 V2 Breadboard-friendly ATmega328P Arduino-compatible board at 16 MHz, 5V, with USB-C, STEMMA QT I2C port, 32KB flash, and CP2102N USB-serial chip — a compact modern drop-in for the Arduino UNO. [Details](https://openhardware.directory/devices/adafruit-metro-mini-328) | [Markdown](https://openhardware.directory/devices/adafruit-metro-mini-328/md) ## Adafruit Feather 32u4 Basic Proto Feather-format ATmega32u4 board at 8 MHz, 3.3V with LiPo charging, native USB, onboard prototyping area, 20 GPIO, JST battery connector, and 100mA integrated charger — all in 51×23mm. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-basic-proto) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-basic-proto/md) ## Adafruit Feather 32u4 Adalogger Feather-format ATmega32u4 data logger at 8 MHz, 3.3V with onboard microSD slot, LiPo charging, native USB, 20 GPIO, and 100mA charger — built for portable data logging applications. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-adalogger) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-adalogger/md) ## Adafruit Feather 32u4 Bluefruit LE Feather-format ATmega32u4 board with integrated nRF51822 Bluetooth LE, LiPo charging, native USB, 20 GPIO, and over-the-air firmware updates — an all-in-one BLE development board for iOS and Android connectivity. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-bluefruit-le) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-bluefruit-le/md) ## Adafruit Feather 32u4 RFM69HCW (868/915 MHz) Feather-format development board combining the ATmega32u4 microcontroller with an RFM69HCW 868/915 MHz packet radio for low-power sub-GHz wireless applications. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-rfm69hcw) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-rfm69hcw/md) ## Adafruit Feather 32u4 RFM96 LoRa (433 MHz) Feather-format development board combining the ATmega32u4 microcontroller with an RFM96 LoRa 433 MHz transceiver for long-range, low-power IoT applications. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-rfm96) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-rfm96/md) ## Adafruit Feather 32u4 RFM95 LoRa (900 MHz) Feather-format development board combining the ATmega32u4 microcontroller with an RFM95 LoRa 868/915 MHz transceiver for long-range, low-power IoT applications. [Details](https://openhardware.directory/devices/adafruit-feather-32u4-rfm95) | [Markdown](https://openhardware.directory/devices/adafruit-feather-32u4-rfm95/md) ## Arduino Nano Every Compact 45×18mm Arduino Nano with ATMega4809 at 20MHz — 48KB flash, 6KB SRAM, 5V logic, 14 digital I/O (5 PWM), 8 analog inputs, and USB-C. A modern, affordable 8-bit board for embedded projects and breadboard prototyping. [Details](https://openhardware.directory/devices/arduino-nano-every) | [Markdown](https://openhardware.directory/devices/arduino-nano-every/md) ## Arduino Uno Rev3 The original Arduino UNO — the world's most popular development board with ATmega328P at 16MHz, 32KB flash, 2KB SRAM, 14 digital I/O (6 PWM), 6 analog inputs, USB-B, and 5V operation. The gateway to electronics and programming for millions. [Details](https://openhardware.directory/devices/arduino-uno-rev3) | [Markdown](https://openhardware.directory/devices/arduino-uno-rev3/md) ## Arduino Nano The classic breadboard-friendly Arduino — ATmega328P at 16MHz, 32KB flash, 2KB SRAM, 14 digital I/O (6 PWM), 8 analog inputs, Mini-B USB, and 5V operation in a tiny 45×18mm form factor. The compact original. [Details](https://openhardware.directory/devices/arduino-nano) | [Markdown](https://openhardware.directory/devices/arduino-nano/md)