Solution for Timed out waiting for packet header on MacBook with Arduino

When trying to upload code to the Wemos D1 R2 Arduino on my MacBook, I kept encountering an error.

The error message was as follows:

A fatal esptool-py error occurred: Failed to connect to ESP8266: Timed out waiting for packet headerUser

And in the terminal, outputs from previous code uploads kept appearing.

Solution for Timed out waiting for packet header on MacBook with Arduino-1

It seemed that some issue was preventing my code from being uploaded to the Arduino.

No matter how much I asked ChatGPT, it couldn't give a precise reason, so I kept searching and asking GPT again until I found the cause.

1. Is the CH340 chipset driver the problem?

Most issues found through searches were solved by installing the CH340 chipset driver.

The official site I found through searches stated the following:

Solution for Timed out waiting for packet header on MacBook with Arduino-2

According to the text, there's no need to install chipset drivers for MacBook versions after Mojave.

Since Apple provides its own drivers, installing them might cause conflicts and result in issues.

Through searching, I finally found the problem.

The cause of the error was the USB hub.

Due to the nature of MacBooks, with not enough USB ports or no Type A USB ports, a hub is often used.

I also connected the Arduino using a USB hub as shown below:

Solution for Timed out waiting for packet header on MacBook with Arduino-3

This causes slight timing variations in the flash signal sent to the Arduino, preventing the board from entering flash mode automatically.

There’s a GitHub troubleshooting section on this issue.

Such issues are prominent when connecting from USB-C to USB-A type.

Solution for Timed out waiting for packet header on MacBook with Arduino-4

If you connected the Arduino using a USB port, you must forcibly put the Arduino into flash mode.

First, connect the board's GPIO0(D3) pin and ground (GND) pin.

Then press the board's reset button.

Solution for Timed out waiting for packet header on MacBook with Arduino-5

This will enter flash mode on the board.

If you remove the pins, it will exit flash mode, so do not remove the pins before uploading.

Then try uploading the file on Arduino....

Solution for Timed out waiting for packet header on MacBook with Arduino-6

It uploads successfully.

After the upload is complete, you can remove the pins.

I wasted a total of 5 hours trying various things with the Arduino yesterday.

However, once you learn something through trial and error, that memory stays with you for a very long time.

I think I can help someone around me if they encounter the same issue next time.

After contemplating since last night, I finally feel relieved.

The thrill of solving a problem after hard work is always enjoyable.

Solution for Timed out waiting for packet header on MacBook with Arduino-7