If you've ever struggled to use a solderless breadboard with an Arduino, you understand how frustrating it can be! I designed this Arduino clone to solve this problem in an inexpensive DIY fashion.

The Boarduino is an Arduino clone: when programmed with the Arduino bootloader, it can talk to the Arduino software and run sketches just like the original.

There are noticable differences between the Boarduino and the Arduino.

• Shields cannot be used as the form factor is so different
• There are two versions, a DC version and a USB version
  For the DC version there isn't an on-board USB chip. This means you need to use a USB-TTL cable or a MiniUSB (or any other FTDI breakout board) which is not included. There are also no rx/tx LEDs and no rx/tx 1K series resistors.
  For the USB version, there is an on-board USB chip but there isn't a DC jack or 5V regulator, you can power it through the USB jack. There is a rx 1K resistor so you can use this to talk to serial accessories.
• 16.00 MHz ceramic resonator is used instead of crystal, so cycle speed may be off by +- 0.3nS (0.5%). This isn't relevant for UART timing, servo drivers, PWM, etc. but could be an issue if you need nanosecond-precision timing. Note that the Arduino software only provides millisecond-precision timing for general sketches (1 second = 1000ms. 1ms = 1,000,000 ns)

The specifications for the DC boarduino include:

• Designed to plug into a breadboard for easy prototyping
• Petite size, only 3" x 0.8" (75mm x 20mm)
• All 'standard' pins are brought out - Digital 0 thru 13, Analog 0 thru 5, ARef, 5V, Ground, Vin and Reset
• 2 LEDs, green power and red "pin 13" LED just like the Arduino Diecimila
• Standard Reset button
• ATmega328P, running at 16.00 MHz, just like the latest Arduino, the Duemilanove (note that the product photo above hasn't been updated)
• 6-pin standard ICSP header
• Standard 2.1mm DC jack (just like the original Arduino) with 5V regulator to run on 7V-17V power (DC)
• USB or External power, selectable with a jumper (just like original Arduino)
• 1N4001 diode protects against using incorrect wall adapter
• 6-pin header at the end for a USB-TTL cable
• Auto-reset capability when used with a USB-TTL cable
• Available as a low cost kit with standard parts, so its never out of stock
• All through-hole parts are easy to solder

The specifications for the USB boarduino include:

• Designed to plug into a breadboard for easy prototyping
• Petite size, only 2.75 " x 0.8" (75mm x 20mm)
• All 'standard' pins are brought out - Digital 0 thru 13, Analog 0 thru 5, ARef, 5V, Ground, 3.3V and Reset
• 2 LEDs, green power and red "pin 13" LED just like the Arduino Diecimila
• Standard Reset button
• ATmega328, running at 16.00 MHz, just like the Duemilanove
• 6-pin standard ICSP header
• Standard mini-USB jack
• USB or external power, selectable with a jumper
• 500mA fuse protects your computer from current overdraw
• Auto-reset capability
• Available as a low cost kit with standard parts, so its never out of stock
• All through-hole parts are easy to solder - SMT chip is presoldered & tested when purchased as a kit

If you have a USB boarduino check this page for instructions!

Steps

This is a very easy kit to make, just go through each of these steps to build the kit.

Prep

Learn how to solder with tons of tutorials!
Don't forget to learn how to use your multimeter too!

Tools

There are a few tools that are required for assembly. None of these tools are included. If you don't have them, now would be a good time to borrow or purchase them. They are very very handy whenever assembling/fixing/modifying electronic devices! I provide links to buy them, but of course, you should get them where ever is most convenient/inexpensive. Many of these parts are available in a place like Radio Shack or other (higher quality) DIY electronics stores.

Check to make sure your kit comes with the following parts.Sometimes we make mistakes so double check everything and email [email protected] if you need replacements!

The first step is to solder the kit together. If you've never soldered before, check the Preparation page for tutorials and more.

If you have a USB boarduino check this page for instructions!

Check the kit to verify you have all the parts necessary, then get your tools ready! A board vise, soldering iron & solder , diagonal cutters, and a solder sucker (desoldering tool) if you have one.

Check to make sure your kit comes with the following parts.Sometimes we make mistakes so double check everything and email [email protected] if you need replacements!

The USB Boarduino is almost completely assembled. Finishing it up should only take a few minutes.

Check the parts in the bag, you should have the tested USB Boarduino board, a stick of 0.1" header, a 2x3 ISP header, a 28pin socket and a preprogrammed ATmega328p.

If you want to socket the microcontroller (we suggest it) Place the socket so that the U notch matches the U printed in the silkscreen. If you don't think you'll ever need to replace the microcontroller and you want a slimmer package, skip this stip.

If you have sharp nails you can bend over two of the socket pins to keep them in place.

Solder all 28 pins well.

Take the microcontroller out of the foam and carefully bend all the pins so they are straight. We like to grip the chip by the edges and press it against a tabletop.

Once the pins are straight, insert the chip by matching the U notch in the chip with the U notch in the socket.

Next, you can attach header pins to make the USB Boarduino fit nicely into a breadboard. If you want to solder wires to the pins instead (free-wiring) you should skip this step.

Break the break-away header into four pieces: 4 pin, 6 pin, and two 8 pin.

Stick them into any breadboard as shown, they should match up with the USB Boarduino so compare as you place the pieces.

Slip the USB Boarduino on top, it should easily fit.

Solder all the pins!

Using with the Arduino IDE

You can use any version of the IDE, when you plug in the USB boarduino it will show up as COM port (install the FTDI drivers that come with the IDE package if you're running Windows or Mac and have not done it yet).

Select Diecimila/Duemilanove with 328P in the Boards menu!

About the Design

Microcontroller

The chip is a ATMega328P which is a standard Arduino-core chip. It comes preprogrammed with a slight modification of the Arduino "Duemilanove" bootloader which takes up 2K. We did not use the bleeding-edge OPTIBOOT as we'd like to wait until its more stable.

The chip is clocked with a 16MHz crystal.

Serial Converter

The serial converter is soldered on board, it is a FT232RL. It works great as a USB/serial chip. There are two LEDs connected to it, labeled RX and TX which will blink when data is received or transmitted. A capacitor between the DTR pin and the AVR's Reset pin acts as the auto-reset for reprogramming, which is standard on all classic Arduinos.

Fuse

The USB boarduino has a 500mA fuse between the USB 5V pin and the rest of the board. If you draw over 500mA it will trip (it tends to trip at about 1 Amp).

RESET Button

There is a single button that you can press to reset the board, the board has the Arduino bootloader auto-reset capability so you don't need to press this before uploading.

LEDs

There are two LEDs on either side of the USB port. The green one indicates power (its lit if the board has power) and the red one is connected to pin 13 just like classic Arduinos. You can use the pin 13 LED for debugging. It will also blink during bootloading and right before the bootloader starts.

PWR Jumper

The PWR solder-jumper is a bonus for advanced users, it allows you to run the USB Boarduino at a different voltage. It is by default shipped with a trace connecting the two jumper sides, which means that the AVR is running at 5V from the USB port. If you would like to say, run the AVR at 3.3v, you can cut the jumper with a sharp xacto/craft blade (check with your multimeter that it is no longer shorted) and then on the breadboard, connect the *VCC* pin to the 3v pin. This will run the board off of the FTDI chip's internal 3.3v regulator, which we should warn you can't supply more than maybe 50mA. Also, be aware that running a 16MHz AVR at 3.3v is considered 'overclocking'. We've never had a problem with it for hobbyist use but just be aware that this is outside the guaranteed performance of the microcontroller.

ISP Header

If you want to use the chip as a non-Arduino, rather you just want it as an AVR devboard, you can reprogram it via the ISP port. We provide a 2x3 pin standard ISP header. Pin 1 is indicated with a circle.

Downloads

All files are at the GitHub repository Click Download to get the files!

The Boarduino is basically like an Arduino. By default it comes with a chip preprogrammed with the Arduino bootloader (also known as an STK500v1 bootloader) but you can use it as a general purpose AVR module.

Using with the Arduino IDE

You can use the board as a "Diecimila / Duemilanove" compatible. Dont forget to do the 'autoreset hack below or it wont auto-reset when its time to program.

Remember to check if you have a '168 chip or '328p chip (look at the chip!) ... If you have a '328p select "Diecimila/Duemilanove with 328P" or you will not be able to talk to it!

Using with a Breadboard

The Boarduino is designed to be inserted into a solderless breadboard, any standard breadboard will be suitable. Simply insert into the breadboard, making sure that the header pins are straight so that they can be easily inserted.

To remove, grab both ends of the board and gently rock back and forth. This will keep the header pins from bending.

Adding USB with an FTDI cable

The easiest way to start loading Arduino sketches into the DC Boarduino is to use a FTDI USB cable. These cables have the USB chip inside the cable and a 6-pin socket on the end.

This socket plugs into the Boarduino as shown, and then you can simply plug the USB A connector into your computer. Use the same drivers that you would use with a normal Arduino.

Don't forget to place the jumper into the USB position so you can powr it from the FTDI friend or cable!

Arduino Compatibility

The bootloader installed is a cross between the NG and Diecimila. There is a 7-second timeout after pressing the reset button but once a sketch is uploaded it starts immediately.

If you'd like to have the auto-reset capability, make sure C6 is soldered in. With Mac's and Linux it should just work fine.

If you're using Windows you'll need to make a slight change to the driver preferences. In the Device Manager, select the USB COM port.

Then right click and select Properties.

Click on the Port Settings tab, and click on Advanced...

Make sure Set RTS On Close is selected.

Note that, sadly, the Boarduino will not automatically start the sketch after upload if you do this. Its a bit of a tradeoff and you may find that pressing the reset button is faster and getting auto-start is better for you.

Programming

There is also a standard 6-pin ICSP (In-Circuit Serial Programming) cable that can be used to burn a new bootloader or just reprogram the chip.

High Power

If you are planning to draw a lot of power from the 5V regulator, say for servos or many LEDs, you may want to add a heatsink to the 7805. Just bend the regulator back a bit and slip one on.

Here are some projects built with Boarduinos...just to give you an idea of what's possible!

Use Terminal Blocks

Terminal screw-blocks allow lightweight ultra-quick prototyping: just tighten the little screws to add or remove components! Use Phoenix brand 0.1" terminal blocks, part 1725672 (4-position),1725698 (6-position), 1725711 (8-position), 1725724 (9-position).

DC Boarduino

• Schematic and Board files in EAGLE CAD format
  
• Schematic as PNG
  
• These are released as-is under Creative Commons 2.5 - Attribution - Share Alike
  

USB Boarduino

• Schematic and Board files in EAGLE CAD format
• Schematic as PNG
• These are released as-is under Creative Commons 2.5 - Attribution - Share Alike
• Fritzing object in the Adafruit Fritzing Library

• Official Arduino site
• Freeduino - True Open Source Arduino designs
• Modern Device - Other Arduino Clones
• FTDI TTL-232R cable
• Arduino Tutorials - These are for traditional Arduinos but can easily be adapted for use with a Boarduino
• Arduino hacks