Arduino Uno Board close-up

How to install the Arduino bootloader

Installing the bootloader is the first step to bringing your Arduino projects to life. This is a program that helps you to easily upload the Arduino sketches repeatedly to the board without the need for special programming equipment.


While this may sound like rocket science, it’s actually simpler than you might think – even for beginners. We’ll show you how to easily install (or reinstall) the bootloader on your Arduino board in a few simple steps.

But first, what exactly is a bootloader on an Arduino board?


What is a bootloader?

The Arduino bootloader is a small program stored in the board’s non-volatile memory that is executed every time the board is powered on, loaded with new code, or reset. When the bootloader is executed, it initializes the board’s hardware and then loads the main sketch or program stored in the board’s flash memory.

It should be noted that all Arduino boards come with a pre-installed bootloader from their respective manufacturers. Sometimes you may find boards with a faulty bootloader. However, this rarely happens.

Why use Bootloader?

There are many situations where using the Arduino bootloader can be useful. For example, if you are new to the Arduino platform, using a bootloader can make it easier and faster to load new software onto your board. This is because you do not need to use external programming hardware, such as a programmer or USB-to-serial adapter, to upload your code.

If you are working on a project that requires frequent code updates, you will find it very useful. In this case, using a bootloader can save you time and effort, as you can simply load the new code onto the board without having to use external programming hardware.

Additionally, if you are working on a Project that requires an Arduino Being in a certain state when you boot it up, like running a certain program, then using the bootloader can be helpful. The bootloader allows you to set the initial state of the board so that when it is turned on, the required program will be automatically launched.

Finally, it provides a way to restore the Arduino if the main sketch is damaged or fails to turn on.

Why is there no my bootloader?

Error image with green 1s and 0s.

There could be four possible reasons why your board might need a new bootloader:

  1. There is no pre-installed bootloader: It’s common to have several standalone ATMEGA328P projects where you solder your chip onto a PCB and the chip happens to fry. Thus it may be possible to replace the board with a chip without pre-installing the bootloader.
  2. Bootloader has been replaced: You could have replaced your bootloader with a modified third party bootloader that might be corrupt.
  3. corrupted loader: This is the least likely scenario. However, in some cases, the Arduino flash memory can get corrupted.
  4. extended memory: If you completely replace (flashing) the bootloader of your application to enjoy the remaining 2KB of program memory, your bootloader is definitely missing.

Here’s what you need to do.

Install/reinstall the Arduino bootloader

Microcontrollers are usually programmed before they are soldered into a PCB. This is usually done using In-System Programming (ISP), such as In-Circuit Serial Programming (ICSP), which allows the microcontroller to be programmed using an external programmer. Many microcontroller manufacturers, such as Atmel and Microchip, provide an ISP header on their boards for this purpose.

Use another Arduino board

In order to flash the bootloader on the ATmega328 microcontroller, you need to use the ICSP header on the board before you can install the bootloader using the other board as an ISP programmer.

Launch the Arduino IDE, and go to Arduino as shown below, and upload the example code to the board you intend to use as a programmer. (Follow the video tutorial to connect the devices).

Arduino IDE File Screenshot for Navigation >> Examples >> ArduinoISP >> ArduinoISP” data-img-url =”https://static1.makeuseofimages.com/wordpress/wp-content/uploads/2022/12/arduino-ide-isp-example.jpg”/> </picture> </figure>
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The icon should look like this so you know you’re on the right track.

Arduino-IDE example code for ISP

From Tools tab, go to programmer Then click Arduino as ISP As shown below.

Screenshot of Arduino-IDE Navigation Tools >> Programmer >> Arduino as ISP” data-img-url =”https://static1.makeuseofimages.com/wordpress/wp-content/uploads/2022/12/arduino-ide-programmer.jpg”/> </picture> </figure>
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Finally, who Tools Tab again, click Burn Bootloader as shown.

Screenshot of Arduino-IDE to navigate through Tools >> Burn the bootloader” data-img-url =”https://static1.makeuseofimages.com/wordpress/wp-content/uploads/2022/12/arduino-ide-burning-the-bootloader.jpg”/> </picture> </figure>
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Once the process is complete, the target board is now ready for programming.

using a dedicated programmer

Several AVR programming devices are available for this type of installation. One good option you can try is the AVR Pocket Programmer (Windows only) based on Dick Streefland usbtiny and Limore Fried USBtinyISP. Provides a simpler way to program AVR microcontrollers, such as those on Arduino boards. Other than the fact that it is powered by a USB connection, it is the best choice as it is compatible with a variety of programming languages ​​and software, which makes it a versatile tool for any Arduino user.

You can also try other options such as the official Atmel-ICE programmer for ARM microcontrollers – especially if you are not using Windows.

Connect the Arduino board to the programmer and flash the bootloader. Refer to this video tutorial below.

The process should be simple and take no more than 20 seconds.

NB: The target board must be powered on properly before attempting this method. Otherwise, you will not be able to flash a file .hex file to your target.

For professional users, there is a more complicated way to install the bootloader using the command line. It’s not necessary to get to this stage, but it does give you the ability to modify or recompile your code for a more personalized experience.

The first step in the process is to configure the fuse bits, which are part of the AVR chip, and the control settings such as using an external crystal. Use the following command to set the fuse bits:

 avrdude -b 19200 -c usbtiny -p m328p -v -e -U efuse:w:0x05:m -U hfuse:w:0xD6:m -U lfuse:w:0xFF:m 

After the fuse bits are configured, the next step is to transfer a compiled .hex file to the target board and set the lock bits. This will allow you to run the program on the board. Make sure you are in the same directory as the optiboot_atmega328. hex file before entering this command:

 avrdude -b 19200 -c usbtiny -p m328p -v -e -U flash:w:hexfilename.hex -U lock:w:0x0F:m 

NB: These commands are for the Arduino Uno. You will need to reconfigure the fuse modules for the board on file board. txt file and disk AVRDUDE part number parameters And also for them to work.

What are you going to do with Arduino next?

The Arduino bootloader is what makes programming so easy, even for beginners. You can now upload your custom sketches to Arduino and restore the bootloader for future Arduino DIY projects.

#install #Arduino #bootloader

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