Using An Arduino Or Seeeduino For Its FTDI Chip

We think of the Arduino as a rapid prototyping tool but we never thought of it as an FTDI breakout board before. [Ihsan Kehribar] wrote a quick post to show how it’s done. You’ll find an FTDI chip on Arduino boards that have a USB connector. It’s used to handle the USB communications on one side, and TTL serial communications on the other. The serial pins from the chip are mapped to the UART on the AVR chip, and in turn they appear on the pin headers for easy connections. Just load up a really simple sketch(available from Ihsan’s post) to make sure the processor doesn’t get in the way and you’ve got yourself an FTDI breakout board. If you happen to have a Seeeduino there’s even more functionality as the board has a selector switch that allows you to choose between 5V and 3.3V levels.

This doesn’t hold true to the newest generation of Arduino, as those board have replaced the FTDI chip with an ATmega8U2. That’s basically and ATmega8 with native USB handling… fancy.

[Thanks Marcus]

24 thoughts on “Using An Arduino Or Seeeduino For Its FTDI Chip

  1. Dont be confused though, the newer method used by arduino is far far superior. But give it some time to be out and get worked on before you judge it. Once people realize what is possible using a usb enabled micro instead of an ftdi and write the OS code to utilize it you will see what I mean. Hands down the new method is better. And im not afraid to speak my mind if the facts did say that they did it purely to make clones more cost inefficient to produce, but clearly that is not the case considering they are open source, left the bootloader in and clearly did this for other reasons.
    But pertaining to the post any usb enabled chip can do this. Its called a CDC class device, and is a serial emulator. So the usb enabled micro in the UNO can EASILY be made to do the same thing if you understand USB. It can also be made into a MIDI device, quite easily. In the end youll see its a really really good thing how theyre doing it.

  2. There are four solder pads on Duemilanove boards right next to the FTDI chip (silkscreen labelled X3). Guess what they’re connected to.

    You can use these pads to burn (bit bang) a bootloader to a chip without the need for an external AVR programmer. (See

    @addidis, MIDI is the start – your Arduino project could be detected and used as a HID/Mass Storage/Multimedia Controller/etc./etc.

    COM ports are so last decade!

  3. @ Macstupidleetnamedude. If you already have it, soldered and ready to use, why spend an extra 4 + shipping + board etching + soldering time? Cause you just need to be a hardcore internet tough guy, dontcha?

  4. Yeah, I don’t get this “FTDI vs. ATMega8U2 on Arduino good or bad?!” thing either.. I do get the point with Arduino and why it’s useful, but in the end it’s just a protoboard. Someone could even say it’s THE protoboard. But..
    Once you have done your prototyping and take the next step, you decide what connectivity is on the board and what chip does what. You can even use FTDI with Uno, its not like the most expensive thing people connect with Arduino, now is it?

  5. I am not on the side of good or bad, I just think their selling point on it is a bit weak

    “if you know what your doing you can reprogram it …”

    well, why wouldn’t I just reprogram it and skip the whole board + other microcontroller, it is an ATMega8 on there…

  6. I’ve been using this to flash 360 drives for ages. I’m a fan of Arduino, but this just seems to be an excuse to mention them again, anyone who’s ever owned or even read about the Arduino should know this already.

  7. Pretty sad post, no wonder people bitch about arduino hacks being on here. Thanks for pointing out I had an ftdi chip on my Arduino, I never would’ve noticed :(

    How can you do an article on the arduino + FTDI and leave it to a user to post about the X3 pins and programming any Atmega via bitbanging….

    What does arduino uno bring to this this party? Poor quality control and no ftdi? worth mentioning then?

  8. You don’t need the bitbang method if you have 2 arduinos you can link them together and use the first to burn a bootloader on the second :) Heck with a little breakout you probably just need one arduino and a breadboard.

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