To upload a .hex file to an [Arduino board](https://www.ampheo.com/c/development-board-arduino), you can bypass the Arduino IDE and use tools like AVRDUDE (used internally by the IDE) or command-line uploaders. Here's how to do it:

**Step-by-Step: Upload .hex File to Arduino**
**You’ll Need:**
* Arduino board (e.g., Uno, Nano, Mega)
* .hex file (compiled sketch or firmware)
* AVRDUDE installed (comes with Arduino IDE or install separately)
* COM port of the [Arduino](https://www.onzuu.com/manufacturer/arduino)
* Correct board type and upload settings

**Option 1: Using AVRDUDE (Command Line)**
**Command Syntax:**

bash

avrdude -C <path_to_avrdude.conf> -v -patmega328p -carduino -P<COMx> -b115200 -D -Uflash:w:<filename.hex>:i

**Example for Arduino Uno (Windows):**

bash

avrdude -C "C:\Program Files (x86)\Arduino\hardware\tools\avr\etc\avrdude.conf" ^
-patmega328p -carduino -P COM4 -b115200 -D -Uflash:w:"myprogram.hex":i

**Example for Linux/macOS:**

bash

avrdude -C /etc/avrdude.conf -v -patmega328p -carduino -P /dev/ttyUSB0 -b115200 -D -Uflash:w:myprogram.hex:i

**Explanation of Key Parameters:**

**Important Notes:**
* Make sure no other program (like Arduino IDE) is using the COM port.
* Press the Reset button just before uploading if needed (on older boards).
* If you’re unsure of the COM port, check Device Manager (Windows) or ls /dev/tty* on Linux/macOS.

**Option 2: Using XLoader (for Windows)**
If you're on Windows and want a GUI tool:

1. Download XLoader: https://xloader.russemotto.com/
2. Select:

* .hex file
* Device type (e.g., [Arduino Uno](https://www.ampheo.com/product/a000046-25542493), Mega)
* COM port
* Baud rate

3. Click Upload

**Option 3: Arduino IDE with Sketch Precompiled**
If you have the .hex but still want to use the [Arduino](https://www.ampheoelec.de/c/development-board-arduino) IDE:

* Use an external programmer (e.g., USBasp)
* Or use Sketch > Export compiled Binary, then upload it via tools