After using RX and TX pins on Nano for DFPlayer, I can no longer upload code.

Using Arduino Avrdude, stk500, Bootloader issues
1

I desperately need help. I uploaded code to my Nano which uses the RX and TX pins via Arduin's Software Serial library, and now my nano is bricked. I can no longer upload code.

I have two nanos, both from the same place. One did not have the RX and TX code uploaded and continues to work just fine. The other one did have the RX and TX code uploaded and no longer works.

This is the error message I get upon trying to upload code to the bricked nano:

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x27

This is what I get upon trying to burn a bootloader to the bricked nano:

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x03

In addition, the "L" LED is flickering.

The board passes the loopback test.

Is there any way I can restore my board back to the factory defaults and fix this?

2

It might be important that the Nanos only worked to begin with if I had "Old Bootloader" selected.

3

The pins marked TX1 and RX0 on your Nano are also used for communication with your computer, including uploads. Connecting anything to those pins can cause you to no longer be able to upload.

Does the problem still occur even if you have nothing at all connected to the pins on the Nano boards?

4

pert:
The pins marked TX1 and RX0 on your Nano are also used for communication with your computer, including uploads. Connecting anything to those pins can cause you to no longer be able to upload.

Does the problem still occur even if you have nothing at all connected to the pins on the Nano boards?

Thanks for the response, Pert. Yes, I disconnected the TX1 and RX0 from the nano almost immediately assuming that would fix the issue. It didn't. Is there any way I can reset the Nano back to it's factory default of not having a program loaded without just uploading a blank?

5

Why do you use SoftwareSerial on the RX/TX pins of the Nano?

You can try to burn the boot loader using ICSP and see if that fixes the issue.

How did you power the DFplayer? If you powered it from the Nano's 5V pin and the Nano was powered with an external power supply, you might have damaged the 5V regulator.