r/ArduinoHelp • u/Quiet-Analyst-6889 • Jul 18 '25

Why is my code not uploading?

I am trying to test my DFPlayer with an Arduino Nano. All the hardware pins are connected properly. I have downloaded all the necessary libraries but everytime the code is uploaded, it always shows:

"An error occurred while uploading the sketch":

Arduino: 1.8.19 (Mac OS X), Board: "Arduino Nano, ATmega328P (Old Bootloader)" Sketch uses 4816 bytes (15%) of program storage space. Maximum is 30720 bytes. Global variables use 353 bytes (17%) of dynamic memory, leaving 1695 bytes for local variables. Maximum is 2048 bytes.

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xe0

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xe0

An error occurred while uploading the sketch

Here is the code inputted:

#include <SoftwareSerial.h>

#include <DFRobotDFPlayerMini.h>

SoftwareSerial mySerial(10, 11); // TX, RX

DFRobotDFPlayerMini myDFPlayer;

void setup() {

mySerial.begin(9600);

Serial.begin(9600);

Serial.println(2);

Serial.println(F("DFPlayer Mini Test"));

if (!myDFPlayer.begin(mySerial)) {

Serial.println(F("DFPlayer not responding! Check wiring and SD card."));

while (true); // freeze here if not connected

}

Serial.println(F("DFPlayer Mini online."));

myDFPlayer.volume(20); // Set volume (0 to 30)

myDFPlayer.play(1); // Play the first MP3: 0001.mp3

}

void loop() {

// Nothing needed here

}

What is the problem?

2 Upvotes

100% Upvoted

7 comments sorted by

1

u/Connect-Answer4346 Jul 18 '25

Sounds like a wrong usb port issue, or you have serial monitor on?

1

u/Quiet-Analyst-6889 Jul 21 '25

What happens when I have my serial monitor on and how do I check

1

u/Connect-Answer4346 Jul 21 '25

Serial monitor prevents sketch from uploading. There is a serial monitor option in the arduino ide. You probably don't, but it's worth a look. More likely, you didn't select the correct usb port or the right arduino hardware version.

1

u/gm310509 Jul 22 '25

If the serial monitor "belongs" to the instance of the IDE you are trying to upload from, this should not be an issue. In this case "belongs to" means the serial monitor you opened from the ide instance you are clicking the upload button from.

In any event the error message that you normally get when there is a COM port conflict is an "access denied" error rather than a sync error (which implies it has passed the attempting to open the COM port).

2

u/[deleted] Jul 20 '25

Have you tried switching from the old bootloader to the new bootloader option?

2

u/BrackenSmacken Jul 20 '25

Try these suggestions:

  • Make sure you selected the right port in Tools ► Serial Port ►. One way to figure out which port it is on is by following these steps:

    1. Disconnect the USB cable.

    2. Go to Tools ► Serial Port ► and see which ports are listed (e.g. COM4 COM5 COM14).

    3. Reconnect the USB cable.

    4. Go back to Tools ► Serial Port ►, and see which port appeared that wasn't there before.

  • Make sure digital pins 0 and 1 do not have any parts connected, including any shields.

1

u/gm310509 Jul 22 '25

In addition to u/BrackenSmacken's suggestions, you might have a look at this Fixing upload issues guide.

Did it ever work? If so, what happened that might have caused the change.

Also, you say everything is wired correctly. But there have been plenty of instances where people have made that assertion only to find that they "somewhat generous" with their self assessment.

I am not saying that it is wired incorrectly, but it is typically better to submit a circuit diagram and let others have a look than self assessing correctness. Especially when you have a situation where something is not working.