user45348: I have a few MakerBot Mightyboards running off ATmega1280 chips that can no longer use their standard USB port to connect to a computer (to make a long story short, there's a little inductor that blew up between the USB port and the 8u2 chip and it is essentially impossible to replace). I have noticed, however, that they have headers for the RXD1 (PD2) and TXD1 (PD3) pins on the 1280 as seen in this picture:

Would it be possible to hook up an external 8u2 (or similar) chip programmed as a USB to serial converter (something like this) and use it as if it were the normal USB port (e.g. for uploading firmware)?
(I wanted to add atmega1280 as a tag, but it doesn't seem to exist)

user4143: Not directly, no.
The USB interface connects to TX0 and RX0 - you have access to TX1 and RX1. The bootloader is set to look at TX0 and RX0.
You would have to compile and install a new version of the bootloader that is set to use TX1 and RX1.

45348: <p>I have a few MakerBot Mightyboards running off ATmega1280 chips that can no longer use their standard USB port to connect to a computer (to make a long story short, there's a little inductor that blew up between the USB port and the 8u2 chip and it is essentially impossible to replace). I have noticed, however, that they have headers for the RXD1 (PD2) and TXD1 (PD3) pins on the 1280 as seen in this picture:</p>

<p><a href="https://i.stack.imgur.com/jKOX1.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jKOX1.jpg" alt="PD0-PD3 pins on Mightyboard Rev H"></a></p>

<p>Would it be possible to hook up an external 8u2 (or similar) chip programmed as a USB to serial converter (<a href="https://www.dfrobot.com/product-581.html" rel="nofollow noreferrer">something like this</a>) and use it as if it were the normal USB port (e.g. for uploading firmware)?</p>

<p>(I wanted to add atmega1280 as a tag, but it doesn't seem to exist)</p>
 4143: <p>Not directly, no.</p>

<p>The USB interface connects to TX0 and RX0 - you have access to TX1 and RX1. The bootloader is set to look at TX0 and RX0.</p>

<p>You would have to compile and install a new version of the bootloader that is set to use TX1 and RX1.</p>
