ESP8266 Community Forum

- Fri Dec 28, 2018 5:46 pm #79760 Don't assume the board is good : I source these and resell them, and I have to test them as they have the highest failure rate of any board we sell : between 7 and 10% that I receive do not work : check carefully for any bridged solder joints on the header pins and components.

Your settings do look correct. You should use NodeMCU 1.0, but I don't think this affects the ability to program the board.

You are using a new and beta version of Esptool. There have been some changes recently which have caused us issues with the ESP32 boards : the auto-reset doesn't work and we have to manually put the board into boot mode (press the boot button when Esptool is trying to connect). This may not be the issue, but it's worth a try.

- Sun Dec 30, 2018 6:14 pm #79781

It turned out to be another application taking ower the serial port. It was Cura, for my 3D printer.
Closing this app made it work.
The ESP modules can be a little sensitive when it comes to the USB cables.

I find it pretty unlikely my cable is the problem - it's a high quality braided cable. I have tried a few others just to be sure, and I get the same result. The device *is* communicating to some extent as the blue light blinks while attempting to upload. As another test, I used another computer running a newer version of the Arduino IDE with no other COM devices connected nor any other software that could be using the COM ports. This had exactly the same result. I have also tried installing different versions from the board manager - the latest beta, the latest stable, and an older version, all with the same issue. This thing must be broken right? I can't imagine anything else to try.

- Sun Dec 30, 2018 10:23 pm #79784 Hi, I didn't use NodeMCU but used a generic ESP8266 board. The same error message bothered me a lot when I started using it, but it was solved when I realised that for my generic board, I had to manually pull the GPIO0 pin down to ground. (All press en button --> boot button, equivalently)

I heard that NodeMCU can automatically enter the bootloader mode, so I guess my experience is probably not relevant to your problem. But maybe you can try this?

1. Unplug the USB cable, and connect the GPIO0 pin to the GND.
2. plug the USB cable and try uploading the code.
3. When upload is done, remove the GPIO0 --> GND connection wire and reboot the board.

By the way, when using esptool.py, the "chip_id" command may leave the board out of the bootloader mode, so before running the code upload, you may need to reboot the device when keeping GPIO0 connected to GND.

Not very likely that this will help you, but just share my experience with you