The HexBright (or HexBright Flex) is an open-source, programmable LED flashlight from a 2011 Kickstarter project. It's designed with an onboard ATmega328P microcontroller that's fully Arduino-compatible, meaning you don't need to "connect" a separate Arduino board to it—the flashlight is an Arduino. You program it directly via USB using the Arduino IDE, just like any Arduino Uno. It features a high-output CREE LED (up to 500 lumens), a built-in accelerometer for tilt-based controls, a button for input, thermal sensing to prevent overheating, and USB charging.

If you're trying to interface an external Arduino with the HexBright (e.g., via wires for custom control), that's possible but uncommon—let me know more details for specifics. Assuming you're looking to program or customize the HexBright itself, here's a step-by-step guide based on the official resources and community projects.

Hardware Overview

• Microcontroller: ATmega328P (16 MHz, 32KB flash, 2KB RAM).
• LED Driver: Supports PWM for brightness control (0-255 levels).
• Inputs: Tail button (digital), 3-axis accelerometer (I2C), thermal sensor.
• Outputs: Main white LED, 3 status LEDs (red/green/blue).
• Power: Rechargeable 18650 Li-ion battery; USB for charging and programming.
• Programming: Micro-USB port acts as a serial interface (like FTDI on an Arduino).

Setting Up the Arduino IDE for HexBright

1. Download Arduino IDE: Get the latest version from arduino.cc. Version 1.0.1+ is required for compatibility, but newer ones work fine.

2. Install the HexBright Board Definition:

   • Create the folder structure: In your Documents (or user home) folder, make Arduino/hardware/hexbright/.
   • Download the boards.txt file from the community wiki: boards.txt download (or copy-paste from the guide below).
   • Save it in the hexbright folder.
   • Restart the Arduino IDE.
   • Go to Tools > Board > HexBright (it should now appear).

   Example boards.txt content (for reference):

   #####################################################
   HexBright.name=HexBright
   
   hexbright.upload.protocol=arduino
   hexbright.upload.maximum_size=30720
   hexbright.upload.speed=57600
   hexbright.upload.tool=avrdude
   hexbright.upload.verbose=true
   
   hexbright.bootloader.low_fuses=0xff
   hexbright.bootloader.high_fuses=0xde
   hexbright.bootloader.extended_fuses=0x05
   hexbright.bootloader.path=hexbright
   hexbright.bootloader.file=ATmegaBOOT_168_atmega328.hex
   hexbright.bootloader.unlock_bits=0x3F
   hexbright.bootloader.lock_bits=0x0F
   
   hexbright.build.mcu=atmega328p
   hexbright.build.f_cpu=16000000L
   hexbright.build.core=arduino
   hexbright.build.vid=0x2341
   hexbright.build.pid=0x8036
   hexbright.build.usb_product="HexBright Flex"
   hexbright.build.usb_manufacturer="HexBright"
   hexbright.build.board=AVR_HEXBRIGHT
   hexbright.build.verbose=true
   
   

3. Install USB Driver (Windows/Mac):

   • The HexBright uses a CDC/ACM driver. On Windows, install the Arduino drivers or use Zadig for libusbK. On Mac/Linux, it should be plug-and-play.
   • Plug in the HexBright via micro-USB. In Arduino IDE, select Tools > Port and choose the new COM port (e.g., /dev/cu.usbmodem* on Mac).

4. Verify Connection:

   • Load a simple Blink sketch (modify to use the main LED on pin 9).
   • Click Upload. The IDE will compile and flash via USB.

Recommended Libraries and Sample Code

The community-maintained hexbright library simplifies hardware access (e.g., reading the accelerometer, setting PWM brightness).

• Install the Library:
  • Clone or download from GitHub: dhiltonp/hexbright.
  • Extract to your Arduino libraries/ folder (e.g., Documents/Arduino/libraries/hexbright/).
  • Restart the IDE. Examples will appear under File > Examples > hexbright.

Key library functions (from hexbright.h):

• hexbright hb; – Initialize.
• hb.init_hardware(); – In setup().