Burned my USB2TTL chip. Serial still works. Cannot burn firmware anymore.

Hi,

I have an Arduino Nano, and the other day I short circuited it by mistake. The USB2TTL chip died during this process, started throwing smoke and now has a small hole in it. The USB as a result, is not responding as is expected.

But the Arduino per se seems to be working fine. The RX and TX lines are still sending and receiving the correct information (By using an external USB2TTL) and the software on it is running correctly.

What I'm trying to do now is to update the software (sketch) that is running on this device. But I'm getting an error saying "avrdude: stk500_getsync() attempt ..." which means that no communication to the bootloader could be made.

I'm 100% sure that the RX and TX wires are connected correctly as I'm receiving correct responses from the software already running on the Arduino.

So now I'm doubting, is it possible to update the software on the Arduino by just using the RX and TX lines on an Arduino Nano? Or is the bootloader on some other piece of hardware that has died during the process?

Greetings.

You also need the DTR line (for a reset) or push the reset button on the nano at the right time. Look at the nano schematic how it's all connected.

Or use the icsp connector with a suitable programmer .
These are well worth having in your kit .

It finally worked!!! I didn't knew about the DTR line. Connecting it to RESET directly didn't work, but then I found this: - YouTube

In conclusion: To get the Arduino into a Flash Mode, I just had to hold the RESET button while compiling, and when it started the Upload, release the RESET button and it starts the transfer.

Thanks for pointing me to the right direction!