# DFRobot Beetle BLE

> Ultra-compact Arduino Uno-compatible board with BLE 4.0 (CC2540), ATmega328P, sewable gold-plated I/O pads, and wireless programming in a 28.8x33.1mm wearable form factor.

## Quick Facts

- **Brand:** DFRobot
- **Price:** ~$14.9
- **Product Readiness:** Consumer Ready
- **CPU:** AVR 8-bit single-core @ 16MHz
- **CPU Architecture:** AVR 8-bit
- **CPU Cores:** 1
- **RAM:** 2KB SRAM
- **Flash:** 32KB
- **USB:** Micro-USB
- **Power:** 5V USB / VIN (< 8V)
- **Operating Voltage:** 5V
- **Operating Temp:** -10°C to 85°C
- **Dimensions:** 28.8 × 33.1mm
- **Weight:** 10g
- **Antenna:** Built-in PCB antenna

## Connectivity

- **Bluetooth:** BLE 4.0

## Use Cases

- wearable
- e-textiles
- usb-hid-device
- compact-iot-node

## Components

- **ATmega328P** (mcu): Microchip ATmega328P running at 16MHz with 32KB flash, 2KB SRAM, and 1KB EEPROM. Fully compatible with Arduino Uno. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FAtmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)
- **CC2540** (ble-radio): Texas Instruments CC2540 Bluetooth Low Energy 4.0 SoC with -93dBm sensitivity, 50m range, supporting HID and iBeacon profiles. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Fcc2540.pdf&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)

## Protocols

- **I2C** (I2C0): SDA: A2, SCL: A3
- **UART** (Serial): TX: TX, RX: RX

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| D2 | Digital I/O | GPIO | digital-input, digital-output |
| D3 | Digital I/O / PWM | GPIO | digital-input, digital-output, pwm |
| D4 | Digital I/O | GPIO | digital-input, digital-output |
| D5 | 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 / I2C SDA | ADC/I2C | digital-input, digital-output, adc |
| A3 | Analog Input / I2C SCL | ADC/I2C | digital-input, digital-output, adc |
| TX | UART Transmit | UART | digital-input, digital-output |
| RX | UART Receive | UART | digital-input, digital-output |

## Description

## Overview

The DFRobot Beetle BLE is one of the smallest Arduino BLE boards available, combining an ATmega328P microcontroller (Arduino Uno-compatible) with a TI CC2540 Bluetooth Low Energy 4.0 chip in a compact 28.8x33.1mm package. Part of DFRobot's Bluno series, it supports Bluetooth HID and iBeacon modes with up to 50m range in open field.

The board features V-shaped gold-plated I/O pads designed for sewing into fabric, making it ideal for wearable electronics and e-textile projects. It exposes 4 digital pins, 4 analog inputs, 2 PWM outputs, I2C, and UART interfaces. A standout feature is wireless programming via Bluetooth, eliminating the need for a physical USB connection during development iterations.

With Micro-USB for power and initial setup, 5V operating voltage, and full Arduino IDE compatibility, the Beetle BLE targets wearable projects, Bluetooth HID devices, iBeacon applications, and any compact BLE-enabled project where sewing or embedding into fabric is desired.

## Where to Buy

- [DFRobot](https://openhardware.directory/r?to=https%3A%2F%2Fwww.dfrobot.com%2Fproduct-1259.html&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export) — $14.90

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.dfrobot.com%2Fproduct-1259.html&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FArduinolibrary%2FDFRobot_Bluno_Bettle&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.dfrobot.com%2FBluno_Beetle_SKU_DFR0339&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)
- [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FArduinolibrary%2FDFRobot_Bluno_Bettle%2Fblob%2Fmaster%2FDFR0339-Bluno%2520beetle%2520V1.0.pdf&ref=openhardware.directory&product=dfrobot-beetle-ble&source=md-export)

## Images

![DFRobot Beetle BLE](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-ble/1025ecacf9ad.jpg)
![DFRobot Beetle BLE](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-ble/81b608f9da31.jpg)
![DFRobot Beetle BLE](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-ble/598c9c72e85d.jpg)
![DFRobot Beetle BLE](https://nbg1.your-objectstorage.com/openhardware-directory/entities/dfrobot-beetle-ble/f5f4dbb1348a.jpg)

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