(:div class="answer":)Yes, although it may require some modifications to the Arduino core libraries.

(:div class="answer":)The official Arduino boards are the ones listed on the hardware page. These are boards whose manufacturers work with the Arduino team to ensure a good user experience, compatibility with the Arduino software, and a quality product. In return for their status as official boards, the manufacturers pay a licensing fee to the Arduino team to support the further development of the project.

In general, we restrict use of the name "Arduino" to the official boards. If you find a product under a different name but described as "Arduino compatible", it’s probably not an official board and doesn’t fund continued work on the project.

(:div class="answer":)You can buy an Arduino board from the official store online or from one of the distributors listed on the buy page. If you'd prefer to build your own, see the Arduino Single-Sided Serial board, which can be easily etched and assembled.

(:div class="answer":)Yes, check out our Privacy Policy page. There you will see how we handle visitor's information and our non-disclosure policies.

(:div class="answer":)Yes, check out ourPrivacy Policy page. There you will see how we handle visitor's information and our non-disclosure policies.

(:div class="question":) Do you have a Privacy Policy about my data as registered user (:div class="answer":)Yes, check out | Privacy Policy page.

(:div class="answer":)The official Arduino boards are the ones listed on the hardware page: the Uno, Mega2560, Nano, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models, along with the Ethernet, XBee, motor, and prototyping shields. These are boards whose manufacturers work with the Arduino team to ensure a good user experience, compatibility with the Arduino software, and a quality product. In return for their status as official boards, the manufacturers pay a licensing fee to the Arduino team to support the further development of the project.

(:div class="answer":)If you're making your own board, come up with your own name! This will allow people identify you with your products and help you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just pick a random word that sounds cool. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. While unofficial products should not have "Arduino" in their name, it's okay to describe your product in relation to the Arduino project and platform. Here are a few guidelines that explain which uses we consider reasonable. Not okay:

• Arduino Xxxxxx
• Xxxxxx Arduino
• Arduino Compatible Xxxxxx - use "Xxxxxx (Arduino-Compatible)" instead

Okay:

• Xxxxxx for Arduino - products that work with official Arduino boards (e.g. shields or kits)
• Xxxxxx (Arduino-Compatible) - variations and clones which are software and hardware compatible

Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it. (It's also trademarked by a Hungarian company.)

(:div class="question":)Where is the troubleshooting section? (:div class="answer":)These questions have moved to the troubleshooting section of the Arduino guide.

Troubleshooting

These questions have moved to the troubleshooting section of the Arduino guide.

TroubleshootingThese questions have moved to the troubleshooting section of the Arduino guide.

(:div class="question":) (:div class="answer":)

(:p class="nop":)

(:div class="answer":)These questions have moved to the troubleshooting section of the Arduino guide.

(:divend:)

(:div class="question":)Where is the troubleshooting section?

(:div class="answer":)These questions have moved to the troubleshooting section of the Arduino guide.

Troubleshooting

!!!Troubleshooting

(:div:)

Troubleshooting

Troubleshooting

In general, we try to restrict use of the name "Arduino" to the official boards. If you find a product under a different name but described as "Arduino compatible", it’s probably not an official board and doesn’t fund continued work on the project.

• Physically embedding an Arduino board inside a commercial product does not require you to disclose or open-source any information about its design.
• Deriving the design of a commercial product from the Eagle files for an Arduino board requires you to release the modified files under the same Creative Commons Attribution Share-Alike license. You may manufacture and sell the resulting product.
• Using the Arduino core and libraries for the firmware of a commercial product does not require you to release the source code for the firmware. The LGPL does, however, require you to make available object files that allow for the relinking of the firmware against updated versions of the Arduino core and libraries. Any modifications to the core and libraries must be released under the LGPL.
• The source code for the Arduino environment is covered by the GPL, which requires any modifications to be open-sourced under the same license. It does not prevent the sale of derivative software or its inclusion in commercial products.

In all cases, the exact requirements are determined by the applicable license. Additionally, see the previous question for information about the use of the name “Arduino”.

The Arduino software is also open-source. The source code for the Java environment is released under the GPL and the C/C++ microcontroller libraries are under the LGPL.

(:divend:)

(:div class="question":)

(:div class="question":)

(:div class="question":)

(:div class="question":)

(:div class="question":)

(:div class="question":)

(:div class="question":)

(:linebreak:)

(:div class="question":)What is an Arduino?

(:div class="answer":)Glad you asked, we have a great introduction page on Arduino, click here to read it.

(:div class="question":)What do you mean by open-source hardware?

(:div class="answer":)Open-source hardware shares much of the principles and approach of free and open-source software. In particular, we believe that people should be able to study our hardware to understand how it works, make changes to it, and share those changes. To facilitate this, we release all of the original design files (Eagle CAD) for the Arduino hardware. These files are licensed under a Creative Commons Attribution Share-Alike license, which allows for both personal and commercial derivative works, as long as they credit Arduino and release their designs under the same license.

(:div class="answer":)The Arduino software is also open-source. The source code for the Java environment is released under the GPL and the C/C++ microcontroller libraries are under the LGPL.

(:div class="question":)How can I get an Arduino board?

(:div class="answer":)You can buy an Arduino board from one of the distributors listed on the buy page. If you'd prefer to build your own, see the Arduino Single-Sided Serial board, which can be easily etched and assembled.

(:div class="question":)Who makes Arduino boards?

(:div class="answer":)Most of the official Arduino boards are manufactured by SmartProjects in Italy. The Arduino Pro, Pro Mini, and LilyPad are manufactured by SparkFun Electronics (a US company). The Arduino Nano is manufactured by Gravitech (also a US company).

(:div class="question":)Which are the official Arduino boards?

(:div class="answer":)The official Arduino boards are the ones listed on the hardware page: the Duemilanove, Nano, Mega, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models, along with the Ethernet, XBee, motor, and prototyping shields. These are boards whose manufacturers work with the Arduino team to ensure a good user experience, compatibility with the Arduino software, and a quality product. In return for their status as official boards, the manufacturers pay a licensing fee to the Arduino team to support the further development of the project.

(:div class="answer":)In general, we try to restrict use of the name "Arduino" to the official boards. If you find a product under a different name but described as "Arduino compatible", it’s probably not an official board and doesn’t fund continued work on the project.

(:div class="question":)I want to design my own board; what should I do?

(:div class="answer":)The reference designs for the Arduino boards are available from the hardware page. They're licensed under a Creative Commons Attribution Share-Alike license, so you are free to use and adapt them for your own needs without asking permission or paying a fee. If you're looking to make something of interest to the community, we'd encourage you to discuss your ideas on the hardware development forum so that potential users can offer suggestions.

(:div class="question":)What should I call my boards?

(:div class="answer":)If you're making your own board, come up with your own name! This will allow people identify you with your products and help you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just pick a random word that sounds cool. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it.

(:div class="question":)Can I build a commercial product based on Arduino?

(:div class="answer":)Yes, with the following conditions:

(:div class="answer":)* Physically embedding an Arduino board inside a commercial product does not require you to disclose or open-source any information about its design.

(:div class="answer":)* Deriving the design of a commercial product from the Eagle files for an Arduino board requires you to release the modified files under the same Creative Commons Attribution Share-Alike license. You may manufacture and sell the resulting product.

(:div class="answer":)* Using the Arduino core and libraries for the firmware of a commercial product does not require you to release the source code for the firmware. The LGPL does, however, require you to make available object files that allow for the relinking of the firmware against updated versions of the Arduino core and libraries. Any modifications to the core and libraries must be released under the LGPL.

(:div class="answer":)* The source code for the Arduino environment is covered by the GPL, which requires any modifications to be open-sourced under the same license. It does not prevent the sale of derivative software or its inclusion in commercial products.

(:div class="answer":)In all cases, the exact requirements are determined by the applicable license. Additionally, see the previous question for information about the use of the name “Arduino”.

(:div class="question":)How can I run the Arduino IDE under Linux?

(:div class="answer":)See instructions for Ubuntu Linux, for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information. Or, you can use Arduino from the command line, and not have to install Java.

(:div class="question":)Can I program the Arduino board in C?

(:div class="answer":)In fact, you already are; the Arduino language is merely a set of C/C++ functions that can be called from your code. Your sketch undergoes minor changes (e.g. automatic generation of function prototypes) and then is passed directly to a C/C++ compiler (avr-g++). All standard C and C++ constructs supported by avr-g++ should work in Arduino. For more details, see the page on the Arduino build process.

(:div class="question":)Can I use a different IDE to program the Arduino board?

(:div class="answer":)It is possible to compile programs for the Arduino using other build tools (e.g. Makefiles and/or AVR Studio). You'll need to configure these to link against the appropriate files in the Arduino core libraries. See the description of the Arduino build process.

(:div class="question":)Can I use an Arduino board without the Arduino software?

(:div class="answer":)Sure. It's just an AVR development board, you can use straight AVR C or C++ (with avr-gcc and avrdude or AVR Studio) to program it.

(:div class="question":)Can I use the Arduino software with other AVR boards?

(:div class="answer":)Yes, although it may require some modifications to the Arduino core libraries. See the porting page in the Arduino Google Code project for details.

In general, we try to restrict use of the name "Arduino" to the official boards. If you find a product under a different name but described as "Arduino compatible", it’s probably not an official board and doesn’t fund continued work on the project.

It is possible to compile programs for the Arduino using other build tools (e.g. Makefiles and/or AVR Studio). You'll need to configure these to link against the appropriate files in the Arduino core libraries. See the description of the Arduino build process.

What do you mean by open-source hardware?

Open-source hardware shares much of the principles and approach of free and open-source software. In particular, we believe that people should be able to study our hardware to understand how it works, make changes to it, and share those changes. To facilitate this, we release all of the original design files (Eagle CAD) for the Arduino hardware. These files are licensed under a Creative Commons Attribution Share-Alike license, which allows for both personal and commercial derivative works, as long as they credit Arduino and release their designs under the same license.

The Arduino software is also open-source. The source code for the Java environment is released under the GPL and the C/C++ microcontroller libraries are under the LGPL.

The official Arduino boards are the ones listed on the hardware page: the Duemilanove, Nano, Mega, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models, along with the Ethernet, XBee, motor, and prototyping shields. These are boards whose manufacturers work with the Arduino team to ensure a good user experience, compatibility with the Arduino software, and a quality product. In return for their status as official boards, the manufacturers pay a licensing fee to the Arduino team to support the further development of the project.

In general, we try to restrict use of the name “Arduino” to the official boards. If you find a product under a different name but described as “Arduino compatible”, it’s probably not an official board and doesn’t fund continued work on the project.

The official Arduino boards are the ones listed on the hardware page: the Duemilanove, Nano, Mega, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models, along with the Ethernet, XBee, motor, and prototyping shields. In general, we try to restrict use of the name “Arduino” to the official boards. If you find a product under a different name but described as “Arduino compatible”, it’s probably not an official board and doesn’t support continued work on the project.

The official Arduino boards are the ones listed on the hardware page: the Duemilanove, Nano, Mega, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models, along with the Ethernet, XBee, Motor, and Prototyping Shields. In general, we try to restrict use of the name “Arduino” to the official boards. If you find a product under a different name but described as “Arduino compatible”, it’s probably not an official board and doesn’t support continued work on the project.

Yes, although it may require some modifications to the Arduino core libraries. See the porting page in the Arduino Google Code project for details.

Which are the official Arduino boards?

The official Arduino boards are the ones listed on the hardware page: the Duemilanove, Nano, Mega, Bluetooth (BT), LilyPad, Mini, Pro, Pro Mini, and a few older models. In general, we try to restrict use of the name “Arduino” to the official boards. If you find a product under a different name but described as “Arduino compatible”, it’s probably not an official board and doesn’t support continued work on the project.

Who makes Arduino boards?

Most of the official Arduino boards are manufactured by SmartProjects in Italy. The Arduino Pro, Pro Mini, and LilyPad are manufactured by SparkFun Electronics (a US company). The Arduino Nano is manufactured by Gravitech (also a US company).

Can I build a commercial product based on Arduino?

Yes, with the following conditions:

• Physically embedding an Arduino board inside a commercial product does not require you to disclose or open-source any information about its design.

• Deriving the design of a commercial product from the Eagle files for an Arduino board requires you to release the modified files under the same Creative Commons Attribution Share-Alike license. You may manufacture and sell the resulting product.

• Using the Arduino core and libraries for the firmware of a commercial product does not require you to release the source code for the firmware. The LGPL does, however, require you to make available object files that allow for the relinking of the firmware against updated versions of the Arduino core and libraries. Any modifications to the core and libraries must be released under the LGPL.

• The source code for the Arduino environment is covered by the GPL, which requires any modifications to be open-sourced under the same license. It does not prevent the sale of derivative software or its inclusion in commercial products.

In all cases, the exact requirements are determined by the applicable license. Additionally, see the previous question for information about the use of the name “Arduino”.

Sure. It's just an AVR development board, you can use straight AVR C or C++ (with avr-gcc and avrdude or AVR Studio) to program it.

Can I use an Arduino board without the Arduino software?

Sure. It's just an ATmega168 development board, you can use straight AVR C or C++ (with avr-gcc and avrdude or AVR Studio) to program it.

Can I use the Arduino software with other AVR boards?

Yes, although it may require some modifications to the Arduino core libraries. See the other hardware page for details.

Can I use a different IDE to program the Arduino board?

It is possible to compile programs for the Arduino using a Makefile and the command line?. If you can get your IDE to run make, you should be all set.

If you're making your own board, come up with your own name! This will allow people identify you with your products and help you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just pick a random word that sounds cool. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it.

If you're making your own board, come up with your own name! This will allow people identify you with your products and help you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just borrow the name of your pet or a character from a novel. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it.

If you're making your own board, come up with your own name! This will help people identify you with your products and allow you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just borrow the name of your pet or a character from a novel. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it.

I want to design my own board; what should I do?

You can buy an Arduino board from one of the distributors listed on the buy page. If you'd prefer to build your own, see the Arduino Single-Sided Serial board, which can be easily etched and assembled.

Frequently Asked Questions

These questions have moved to the troubleshooting section of the Arduino guide.

If you're making your own board, come up with your own name! This will help people identify you with your products and allow you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just borrow the name of your pet or a character from a novel. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible). So you might want to avoid it.

What should I call my boards?

If you're making your own board, come up with your own name! This will help people identify you with your products and allow you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just borrow the name of your pet or a character from a novel. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "-duino" suffix, its use causing Italians on the team to cringe (apparently it sounds terrible). So you might want to avoid it.

The reference designs for the Arduino boards are available from the hardware page. They're licensed under a Creative Commons Attribution Share-Alike license, so you are free to use and adapt them for your own needs without asking permission or paying a fee. If you're looking to make something of interest to the community, we'd encourage you to discuss your ideas on the hardware development forum so that potential users can offer suggestions.

Also, see the So you want to make an Arduino document for information on the use of the "Arduino" tradmark and other guidelines.

In fact, you already are; the Arduino language is merely a set of C/C++ functions that can be called from your code. Your sketch undergoes minor changes (e.g. automatic generation of function prototypes) and then is passed directly to a C/C++ compiler (avr-g++). All standard C and C++ constructs supported by avr-g++ should work in Arduino. For more details, see the page on the Arduino build process.

Can I program the Arduino board in C?

In fact, you already are; the Arduino language is merely a set of C/C++ functions that can be called from your code. Your sketch undergoes minor changes (e.g. automatic generation of function prototypes) and then is passed directly to a C/C++ compiler (avr-g++). For more details, see the page on the Arduino build process.

It is also possible to compile programs for the Arduino using a Makefile and the command line?.

See the howto for options, which includes buying a board, or building your own from the files information on the hardware page.

See the howto for options, which includes buying a board, a compatible, or building your own from the files information on the hardware page.

See the howto for options, which includes buying a board, or a compatible or building your own from the files information on the hardware page.

Is Arduino open-source?

Yes. The source code for the Java environment is released under the GPL, the C/C++ microcontroller libraries under the LGPL, and the schematics and CAD files under Creative Commons Attribution Share-Alike licenses.

I want to make my own Arduino boards; what should I do?

Check out the So you want to make an Arduino document for information and guidelines.

What is an Arduino?

Glad you asked, we have a great introduction page on Arduino, click here to read it.

See the howto for options, which includes buying a board or building your own from the files information on the hardware page.

See instructions for Ubuntu Linux, for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information. Or, you can use Arduino from the command line, and not have to install Java.

See the bootloader page for details on burning the bootloader onto an Arduino board.

These questions have moved to the troubleshooting section of the Arduino guide.

Development

See instructions for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information. Or, you can use Arduino from the command line, and not have to install Java.

Arduino 0005 won't start on Mac OS X.

• Make sure you don't have firewall software that blocks access to the serial port (e.g. ZoneAlarm).

Arduino won't start on Mac OS X.

Check your console log (Applications > Utilities > Console). If you see a message like "unsupported major.minor version 49.0", your Java is too old. Run Software Update to upgrade to the latest version.

• You may need to quit Processing, PD, vvvv, etc. if you're using them to read data over the USB or serial connection to the Arduino board.

• Check that you're not running any programs that scan all serial ports, like PDA sync applications, Bluetooth-USB drivers (e.g. BlueSoleil), virtual daemon tools, etc.

See instructions for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information.

See instructions for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information.

See instructions for Debian Linux, for Gentoo Linux, for for Linux on PPC. This this forum thread has more information.

See instructions for Debian Linux, http://jeremah.co.uk/linux/arduino_on_gentoo.html fo Gentoo Linux, for for Linux on PPC. This this forum thread has more information.

• Or (especially on Intel Macs), the bootloader on the Arduino board might time out before the compilation of the new sketch finishes and the upload begins. Here's plaidTortoise's fix: "To get it to work I hold down the reset button, click the Upload button and wait a couple of seconds. Then I release the button and a second or so later both the TX and RX Leds on the board light up and both start flashing. The upload then occurs."

Why does my sketch appear to upload successfully but not do anything?

The sketch may be too big for the board. When uploading your sketch, Arduino 0004 checks if it's too big for the ATmega8, but it bases its calculation on a 1 Kb bootloader. You may have a older bootloader that takes up 2 Kb of the 8 Kb of program space (flash) on the ATmega8 instead of the 1 Kb used by the current bootloader. If yours is bigger, only part of the sketch will be uploaded, but the software won't know, and your board will continually reset, pause, reset.

If you have access to an AVR-ISP or parallel port programmer, you can burn the latest version of the bootloader to your board with the Tools | Burn Bootloader menu item. Otherwise, you can tell the Arduino environment the amount of space available for sketches by editing the upload.maximum_size variable in your preferences file (see: instructions on finding the file). Change 7168 to 6144, and the environment should correctly warn you when your sketch is too big.

Why won't Arduino run on old versions of Mac OS X?

If you get an error like this:

@@Link (dyld) error:

dyld: /Applications/arduino-0004/Arduino 04.app/Contents/MacOS/Arduino Undefined symbols: /Applications/arduino-0004/librxtxSerial.jnilib undefined reference to _printf$LDBL128 expected to be defined in /usr/lib/libSystem.B.dylib @@

you probably need to upgrade to Max OS X 10.3.9 or later. Older versions have incompatible versions of some system libraries.

Thanks to Gabe462 for the report.

Arduino 0004 includes a universal version of the RXTX library and should run without modifications on Intel Mac machines. Please report success or failure to the forum.

What do to if I get the following error when launching arduino.exe on Windows?

What about this error?

Java Virtual Machine Launcher: Could not find the main class. Program will exit.

Make sure that you correctly extracted the contents of the Arduino .zip file - in particular that the lib directory is directly inside of the Arduino directory and contains the file pde.jar.

• Or, the bootloader on the Arduino board might time out before the compilation of the new sketch finishes and the upload begins. Here's plaidTortoise's fix: "To get it to work I hold down the reset button, click the Upload button and wait a couple of seconds. Then I release the button and a second or so later both the TX and RX Leds on the board light up and both start flashing. The upload then occurs."

How can I reduce the size of my sketch?

The ATmega8 chip on the Arduino board is cheap, but it has only 8 Kb of program code, which isn't very much (and 1 Kb is used by the bootloader).

If you're using floating point, try to rewrite your code with integer math, which should save you about 2 Kb. Delete any #include statements at the top of your sketch for libraries that you're not using.

Otherwise, see if you can make your program shorter.

In new releases of the software, we'll try to make more efficient use of the program space and give an error message if your program is too big.

How can I run the Arduino IDE under Linux?

• You may need change the baud rate at which sketches are uploaded. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). You will have to change the speed in the preferences file directly. See the preferences page for instructions on finding the file. Look for the file in your computer and change the serial.download_rate property to match the one in your board. Though this is a trick to fix this issue, it is recommended to upgrade the bootloader, the one that downloads always at 19200. This can be done with the 'Tools | Burn Bootloader menu item.

You'll need to launch Arduino using the run.bat file. Please be patient, the Arduino IDE may take some time to open.

You need to run the macosx_setup.command in the Arduino directory, and then restart your computer. Arduino 0004 includes a modified version of this script that all users need to run (even those who ran the one that came with Arduino 0003). You may also need to delete the contents of the /var/spool/uucp directory.

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). You will have to change the speed in the preferences file directly. See the preferences page for instructions on finding the file. Look for the file in your computer and change the serial.download_rate property to match the one in your board. As explained earlier, some older boards still download programs at the speed of 9600. Newer boards use 19200. Though this is a trick to fix this issue, it is recommended to upgrade the bootloader, the one that downloads always at 19200. This can be done with the 'Tools | Burn Bootloader menu item.

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). You will have to change the speed in the preferences file directly. See the preferences page for instructions on finding the file.

You need to run the macosx_setup.command in the Arduino directory, and then restart your computer. You may also need to delete the contents of the /var/spool/uucp directory.

Why don't I get a PWM (an analog output) when I call analogWrite() on pins other than 9, 10, or 11?

How do I burn the bootloader onto my board?

See the bootloader page for details on burning the bootloader onto an Arduino board.

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). If you run Arduino-0003, you will have to change the speed in the preferences file directly. See the preferences page for instructions on finding the file.

Look for the file in your computer and change the serial.download_rate property to match the one in your board. As explained earlier, some older boards still download programs at the speed of 9600. Newer boards use 19200.

Though this is a trick to fix this issue, it is recommended to upgrade the bootloader, the one that downloads always at 19200. This can be done with the 'Tools | Burn Bootloader menu item.

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). If you run Arduino-0003, you will have to change the speed in the preferences file directly. See the preferences] page for instructions on finding the file.

See this forum thread for instructions on getting Arduino to run in Debian. Those of you crazy enough to run Linux on PPC hardware should see this thread. For Gentoo, see these instructions from Jonny Stutters.

If you're using a USB Arduino board, make sure you installed the FTDI drivers (see the Howto for directions). If you're using a USB-to-Serial adapter with a serial board, make sure you installed its drivers.

Make sure that the board is plugged in: the serial port menu refreshes whenever you open the Tools menu, so if you just unplugged the board, it won't be in the menu.

Check that you're not running any programs that scan all serial ports, like PDA sync applications, Bluetooth-USB drivers (e.g. BlueSoleil), virtual daemon tools, etc.

The Arduino software won't run on Intel Mac machines.

Arduino 0003 uses a native library for doing serial communication that was only compiled for PPC. You'll need to build your own version of RXTX. See this forum thread for more details.

What if I get this error when uploading code or using the serial monitor (on the Mac)?

Error inside Serial.<init>() 
gnu.io.PortInUseException: Unknown Application 
     at gnu.io.CommPortIdentifier.open(CommPortIdentifier.java:354) 
     at processing.app.Serial.<init>(Serial.java:127) 
     at processing.app.Serial.<init>(Serial.java:72) 

You need to run the macosx_setup.command in the Arduino directory, and then restart your computer.

First, make sure you're not running any programs that scan all serial ports, like PDA sync applications, Bluetooth-USB drivers (e.g. BlueSoleil), virtual daemon tools, etc.

• Make sure there's a bootloader burned on the Atmega8 on your Arduino board. To check, connect an LED to pin 13 and reset the board. The LED should blink. If it doesn't, see the Bootloader page for instructions on burning a bootloader to the board.

• Be sure that you are resetting the board a couple of seconds before uploading.

• Also, on the serial boards, be sure that digital pins 0 and 1 are not connected to anything while uploading (they can connected and used after the code has been uploaded).

• If you get this error: [VP 1] Device is not responding correctly. try uploading again (i.e. reset the board and press the download button a second time).

Why doesn't my board show in the Tools | Serial Port menu ?

On Windows, the COM port assigned to the board may be too high. From zeveland:

On the Mac, if you have an old version of the FTDI drivers, you may need to remove them and reinstall the latest version. See this forum thread for directions (thanks to gck).

See this forum thread for instructions on getting Arduino to run in Debian. Those of you crazy enough to run Linux on PPC hardware should see this thread.

How can I run the Arduino IDE under Linx?

See this forum thread for instructions on getting Arduino to run in Debian. Those of you crazy enough to run Linux on PPC hardware should see this thread.

Why doesn't my board show in the Tools | Serial Port menu on Windows?

The COM port assigned to the board may be too high. From zeveland:

"One little note if you aren't able to export and your USB board is trying to use a high COM port number: try changing the FTDI chip's COM port assignment to a lower one.

"I had a bunch of virtual COM ports set up for Bluetooth so the board was set to use COM17. The IDE wasn't able to find the board so I deleted the other virtual ports in Control Panel (on XP) and moved the FTDI's assignment down to COM2. Make sure to set Arduino to use the new port and good luck."

My code appears to upload correctly, but doesn't run.

Your program is probably too big for the Arduino board. The ATmega8 chip has only 8 Kb of program code, which isn't very much (and 1 Kb is used by the bootloader). If you're using floating point, try to rewrite your code with integer math, which should save you about 2 Kb. Otherwise, see if you can make your program shorter. This is one of the limitations that we have to deal with in order to make the Arduino board as cheap as possible. In new releases of the software, we'll try to make more efficient use of the program space and give an error message if your program is too big.

What do to if I get the following error when launching arduino.exe on Windows? (how to use run.bat)

'''What do to if I get the following error when launching arduino.exe on Windows? (how to use run.bat)"

Arduino has encountered a problem and needs to close.

You'll need to launch Arduino using the run.bat file. To do so, you'll need to change the line that reads:

set JAVA_HOME=""

to:

set JAVA_HOME="java\bin"

Thanks to Tom Igoe for the bug report.

The microcontroller on the Arduino board (the atmega8) only supports PWM/analogWrite() on certain pins. Calling analogWrite() on any other pins will give high (5 volts) for values greater than 128 and low (0 volts) for values less than 128.

How do I burn the bootloader onto my board? Why doesn't burn.bat work on Windows?

See the bootloader page for details on burning the bootloader onto an Arduino board, including corrected scripts for Windows.

In the File-->Preferences submenu you will open a pop-up window that contains the path for the preferences file in your system (note that the path in the picture belongs to the computer where we made the test, it will for sure be different in your machine - the other issue is that on Windows the file may be in a hidden folder).

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (MOST OF -but not all- version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). If you run Arduino-0003, you will have to change the speed in the preferences file directly. The following picture sequence explains how to find this:

In the File-->Preferences submenu you will open a pop-up window that contains the path for the preferences file in your system (note that the path in the picture belongs to the computer where we made the test, it will for sure be different in your machine).

(note: the properties file will state in the beginning that you shouldn't edit it, do not follow that indication this time)

This is the property you will have to tune: 9600 for old boards, 19200 (as shown in the picture) for new boards. Though this is a trick to fix this issue, it is recommended to upgrade the bootloader to version 4, the one that downloads always at 19200. The file to do this is included in the Arduino-0003 distribution.

If you're using a USB board, make sure that the jumper (little plastic piece near the USB plug) is on the correct pins. If you're powering the board with an external power supply (plugged into the power plug), the jumper should be on the two pins closest to the power plug. If you're powering the board through the USB, the jumper should be on the two pins closest to the USB plug. This picture shows the arrangment for powering the board from the USB port.

(thanks to mrbbp for report and picture)

If you're using a USB board, make sure that the jumper (little plastic piece near the USB plug) is on the correct pins. If you're powering the board with an external power supply (plugged into the power plug), the jumper should be on the two pins closest to the power plug. If you're powering the board through the USB, the jumper should be on the two pins closest to the USB plug. (thanks to mrbbp for report and picture)

• Make sure there's a bootloader burned on the Atmega8 on your Arduino board. To check, connect an LED to pin 13 and reset the board. The LED should blink. If it doesn't, see the Bootloader page for instructions on burning a bootloader to the board.

Explanation: On the newer versions of the board, the order of the analog input pins was reversed but version 0002 of the software was not updated along with it. This has been fixed in version 0003.

This is the property you will have to tune: 9600 for old boards, 19200 (as shown in the picture) for new boards. Though this is a trick to fix this issue, it is recommended to upgrade the bootloader to version 4, the one that downloads always at 19200. The file to do this is included in the Arduino-0003 distribution.

Look for the file in your computer and change the serial.download_rate property to match the one in your board. As explained earlier, some older boards still download programs at the speed of 9600.

Figure 3: change the serial.download_rate property

[]

[Attach:20060119_serial2.png Δ]

[Attach:20060119_serial3.png Δ]

• Then, make sure you have the right speed (baud rate) selected. If you run Arduino-0002 or older: in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (version 2.0 or greater, and most of the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). If you run Arduino-0003, you will have to change the speed in the preferences file directly. The following picture sequence explains how to find this:

[Attach: 2006019_serial1.png] Figure 1: looking for the preferences

In the File-->Preferences submenu you will open a pop-up window that contains the path for the preferences file in your system.

[Attach: 20060119_serial2.png] Figure 2: the path is indicated in the pop-up

Look for the file in your computer and change the serial.download_speed property to match the one in your board. As explained earlier, some older boards still download programs at the speed of 9600.

[Attach: 20060119_serial3.png] Figure 3: change the serial.download_speed property

Though this is a trick to fix this issue, it is recommended to upgrade the bootloader to version 4, the one that downloads at 19200. The file to do this is included in the Arduino-0003 distribution.

There are a few things that could be wrong.

• First make sure your board is on (the green LED is on) and connected to the computer (if it's not, see "what if my board doesn't turn on" above).

• Then, check that the proper port is selected in the "Tools | Serial Port" menu (if your port doesn't appear, restart the IDE with the board connected to the computer).

• Then, make sure you have the right speed (baud rate) selected in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (version 2.0 or greater, and the Arduino Extreme, which has two red LEDs marked "RX" and "TX").

• Be sure that you are resetting the board a couple of seconds before uploading.

• Also, on the serial boards, be sure that digital pins 0 and 1 are not connected to anything while uploading (they can connected and used after the code has been uploaded).

• If you get this error: [VP 1] Device is not responding correctly. try uploading again (i.e. reset the board and press the download button a second time).

There are a few things that could be wrong. First make sure your board is on (the green LED is on) and connected to the computer (if it's not, see "what if my board doesn't turn on" above). Then, check that the proper port is selected in the "Tools | Serial Port" menu (if your port doesn't appear, restart the IDE with the board connected to the computer). Then, make sure you have the right speed (baud rate) selected in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (version 2.0 or greater, and the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). Be sure that you are resetting the board a couple of seconds before uploading. Also, on the serial boards, be sure that digital pins 0 and 1 are not connected to anything while uploading (they can connected and used after the code has been uploaded). If you get this error:

[VP 1] Device is not responding correctly.

trying uploading again (i.e. reset the board and press the download button a second time).

If you're using a USB board, make sure that the jumper (little plastic piece near the USB plug) is on the correct pins. If you're powering the board with an external power supply (plugged into the power plug), the jumper should be on the two pins closest to the power plug. If you're powering the board through the USB, the jumper should be on the two pins closest to the USB plug. (thanks to mrbbp)

You probably have an old version of the communications library lying around. Search for comm.jar or jcl.jar in /System/Library/Frameworks/JavaVM.framework/ or in directories in your CLASSPATH or PATH environment variables. (reported by Anurag Sehgal)

There are a few things that could be wrong. First make sure your board is on (the green LED is on) and connected to the computer (if it's not, see "what if my board doesn't turn on" above). Then, check that the proper port is selected in the "Tools | Serial Port" menu (if your port doesn't appear, restart the IDE with the board connected to the computer). Then, make sure you have the right speed (baud rate) selected in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (version 2.0 or greater, and the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). Be sure that you are resetting the board a couple of seconds before uploading. Also, on the serial boards, be sure that digital pins 0 and 1 are not connected to anything while uploading (they can connected and used after the code has been uploaded).

What do I do if I get the following error when launching Arduino?

What do I do if I get the following error when launching Arduino?

Uncaught exception in main method: java.lang.UnsatisfiedLinkError: Native Library /Users/anu/Desktop/arduino-0002/librxtxSerial.jnilib already loaded in another classloader

You probably have an old version of the communications library lying around. Search for comm.jar or jcl.jar in /System/Library/Frameworks/JavaVM.framework/ or in directories in your CLASSPATH or PATH environment variables.

See the howto for options, which include buying a board or building your own from the information on the hardware page.

See the Howto for options, which include buying a board or building your own from the information on the Hardware page.

General

How can I get an Arduino board?

Why am I getting garbage data from analogRead()?

Try flipping the pin without changing the code (e.g. if you call analogRead(0), use analog input pin 5 instead of 0).

Explanation: On the newer versions of the board, the order of the analog input pins was reversed but version 0002 of the software was not updated along with it. This should be fixed in version 0003.

Why don't I get a PWM (an analog output) when I call analogWrite() on pins other than 9 or 10?

The microcontroller on the Arduino board (the atmega8) only supports PWM/analogWrite() on certain pins. Calling analogWrite() on any other pins will give high (5 volts) for values greater than 128 and low (0 volts) for values less than 128.

Arduino Frequently Asked Questions

Troubleshooting

Why I can't upload my programs to the Arduino board?

There are a few things that could be wrong. First make sure your board is on (the green LED is on) and connected to the computer. Then, check that the proper port is selected in the "Tools | Serial Port" menu (if your port doesn't appear, restart the IDE with the board connected to the computer). Then, make sure you have the right speed (baud rate) selected in the "Tools | Serial port speed" menu. It should be 9600 for older boards (those with no version numbers) and 19200 for newer boards (version 2.0 or greater, and the Arduino Extreme, which has two red LEDs marked "RX" and "TX"). Be sure that you are resetting the board a couple of seconds before uploading. Also, on the serial boards, be sure that digital pins 0 and 1 are not connected to anything while uploading (they can connected and used after the code has been uploaded).