Is it possible to directly communicate USB D+ D- to Arduino Mega serial port TX RX?

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    Actually it is possible with some passive components to get close enough to the USB spec to usually be able to bit-bang the lowest speed version in software. I believe on the ATmega328 you can do this with fairly arbitrary GPIOs, presumably you can on a mega as well. Oct 20, 2014 at 4:46
  • Despite the answer to the contrary it IS possible to access USB directly from digital I/O pins. As TX & RX are also standard digtal I/O pins they could be used for this purpose BUT you need dedicated bootloader code to do this and it has inferior performance if a USB to serial converter is available. The eg ADAFruit Arduino Trinket uses this system. Feb 18, 2015 at 8:52

1 Answer 1


No, D+/- are high frequency USB signals. TX/RX is 5V UART protocol, i.e. compeletely different. But you can e.g. use AT90USB128x processor to avoid 16u2 bridge. The prosessor is not so mighty as 2560 but it's cheaper and simplifies design.

  • Thanks. I knew it but I was thinking may be arduino mega has an option to go through the 2560 UART. I thought it would be the serial port 0 as it is the port for PC serial monitor. Oct 19, 2014 at 13:25
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    The Arduino Leonardo has a ATMega32u4 witch also supports USB directly. An entire board might be easier than just a raw chip.
    – Gerben
    Oct 19, 2014 at 17:49
  • Well, I have few couple of Arduino Mega, so, I don't really need to have a Leonardo I think. :) Oct 20, 2014 at 2:16

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