# DFRobot Beetle Board

> The original coin-sized Arduino Leonardo-compatible board with ATmega32U4, native USB, 10 digital and 5 analog pins, and sewable gold-plated pads in a 20x22mm form factor.

## Quick Facts

- **Brand:** DFRobot
- **Price:** ~$8.9
- **Product Readiness:** Consumer Ready
- **CPU:** AVR 8-bit single-core @ 16MHz
- **CPU Architecture:** AVR 8-bit
- **CPU Cores:** 1
- **RAM:** 2.5KB SRAM
- **Flash:** 32KB
- **USB:** Micro-USB (native USB 2.0 Full-speed)
- **Power:** 5V via Micro-USB
- **Operating Voltage:** 5V
- **Dimensions:** 20 × 22 × 3.8mm
- **Weight:** 5g
- **Antenna:** N/A

## Use Cases

- usb-hid-device
- e-textiles
- compact-iot-node
- educational-platform

## Components

- **ATmega32U4** (mcu): Microchip ATmega32U4 running at 16MHz with 32KB flash, 2.5KB SRAM, 1KB EEPROM, native USB 2.0, 12-channel 10-bit ADC. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2Fdevicedoc%2Fatmel-7766-8-bit-avr-atmega16u4-32u4_datasheet.pdf&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export)

## Protocols

- **I2C** (I2C0): SDA: D1, SCL: D0
- **UART** (Serial1): TX: D1, RX: D0
- **SPI** (SPI0): MOSI: MOSI, MISO: MISO

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| D0 | UART RX / I2C SCL | UART/I2C | digital-input, digital-output |
| D1 | UART TX / I2C SDA | UART/I2C | digital-input, digital-output |
| D2 | Digital I/O | GPIO | digital-input, digital-output |
| D3 | Digital I/O / PWM | GPIO | digital-input, digital-output, pwm |
| D5 | Digital I/O / PWM | GPIO | digital-input, digital-output, pwm |
| D9 | Digital I/O / PWM / Analog A9 | GPIO | digital-input, digital-output, pwm, adc |
| D10 | Digital I/O / PWM / Analog A10 | GPIO | digital-input, digital-output, pwm, adc |
| D11 | Digital I/O / PWM | GPIO | digital-input, digital-output, pwm |
| A0 | Analog Input | ADC | digital-input, digital-output, adc |
| A1 | Analog Input | ADC | digital-input, digital-output, adc |
| A2 | Analog Input | ADC | digital-input, digital-output, adc |
| SDA | I2C Data | I2C | digital-input, digital-output |
| SCL | I2C Clock | I2C | digital-input, digital-output |
| MOSI | SPI MOSI | SPI | digital-input, digital-output |
| MISO | SPI MISO | SPI | digital-input, digital-output |

## Description

## Overview

The DFRobot Beetle Board is the original coin-sized Arduino Leonardo-compatible microcontroller that started the Beetle product line. Built around the ATmega32U4 with native USB support, it measures just 20x22mm while exposing 10 digital I/O pins, 5 analog input channels, 4 PWM outputs, I2C, and UART interfaces.

The board features V-shaped gold-plated I/O ports with wide-spacing soldering pads and honeycomb-shaped power interfaces, designed for easy hand-soldering and sewable integration into wearable projects. The pre-loaded Arduino Leonardo bootloader enables direct programming via Micro-USB with no additional hardware required.

At just 5 grams, the Beetle Board is one of the lightest Arduino-compatible boards available, making it the go-to choice for weight-sensitive applications like wearables, props, cosplay electronics, and miniature embedded projects. It is fully compatible with existing Arduino Leonardo sketches and libraries.

## Where to Buy

- [DFRobot](https://openhardware.directory/r?to=https%3A%2F%2Fwww.dfrobot.com%2Fproduct-1075.html&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export) — $8.90

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.dfrobot.com%2Fproduct-1075.html&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.dfrobot.com%2FBeetle_SKU_DFR0282&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export)
- [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2Fdevicedoc%2Fatmel-7766-8-bit-avr-atmega16u4-32u4_datasheet.pdf&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export)
- [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fdfimg.dfrobot.com%2Fenshop%2Fimage%2Fdata%2FDFR0282%2FBeetle%2520Sch.pdf&ref=openhardware.directory&product=dfrobot-beetle-board&source=md-export)

## Images

![DFRobot Beetle Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-board/7ecefdaeb122.jpg)
![DFRobot Beetle Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-board/d6c9ddce6f1e.jpg)
![DFRobot Beetle Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-board/da1d45b09f88.jpg)
![DFRobot Beetle Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-board/46a1f52dd16f.jpg)

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