Clone and edit the NodeMCU firmware locally on your platform. This image will take it from there and turn your code into a binary which you then can flash to the ESP8266.

I see 3 types of NodeMCU developers:

• NodeMCU "application developers"

  They just need a ready-made firmware. I created a cloud build service with a nice UI and configuration options for them.

• Occasional NodeMCU firmware hackers

  They don't need full control over the complete tool chain and don't want to setup a Linux VM with the build environment. This image is exactly for them!

• NodeMCU firmware developers

  They commit or contribute to the project on GitHub and need their own full fledged build environment with the complete tool chain. They still might find this Docker image useful.

Follow the instructions at https://docs.docker.com/ → 'Get Started' (orange button top right).

### Clone the NodeMCU firmware repository Docker runs on a VirtualBox VM which by default only shares the user directory from the underlying guest OS. On Windows that is c:/Users/<user> and on Mac it's /Users/<user>. Hence, you need to clone the NodeMCU firmware repository to your user directory. If you want to place it outside the user directory you need to adjust the VirtualBox VM sharing settings accordingly.

git clone https://github.com/nodemcu/nodemcu-firmware.git

Start Docker and change to the NodeMCU firmware directory (in the Docker console). Then run:

docker run --rm -ti -v `pwd`:/opt/nodemcu-firmware marcelstoer/nodemcu-build

Depending on the performance of your system it takes 1-3min until the compilation finishes. The first time you run this it takes longer because Docker needs to download the image and create a container.

‼️ If you have previously pulled this Docker image (e.g. with the command above) you should update the image from time to time to pull in the latest bug fixes:

docker pull marcelstoer/nodemcu-build

Note for Windows users

(Docker on) Windows handles paths slightly differently. You need to specify the full path to the NodeMCU firmware directory in the command and you need to add an extra forward slash (/) to the Windows path. The command thus becomes (c equals C drive i.e. c:):

docker run --rm -it -v //c/Users/<user>/<nodemcu-firmware>:/opt/nodemcu-firmware marcelstoer/nodemcu-build

If the Windows path contains spaces it would have to be wrapped in quotes as usual on Windows.

docker run --rm -it -v "//c/Users/monster tune/<nodemcu-firmware>":/opt/nodemcu-firmware marcelstoer/nodemcu-build

The two firmware files (integer and float) are created in the bin sub folder of your NodeMCU root directory. You will also find a mapfile in the bin folder with the same name as the firmware file but with a .map ending.

You can pass the following optional parameters to the Docker build like so docker run -e "<parameter>=value" -e ....

• IMAGE_NAME The default firmware file names are nodemcu_float|integer_<branch>_<timestamp>.bin. If you define an image name it replaces the <branch>_<timestamp> suffix and the full image names become nodemcu_float|integer_<image_name>.bin.
• INTEGER_ONLY Set this to 1 if you don't need NodeMCU with floating support, cuts the build time in half.
• FLOAT_ONLY Set this to 1 if you only need NodeMCU with floating support, cuts the build time in half.

There are several tools to flash the firmware to the ESP8266. If you were to use esptool (like I do) you'd run:

esptool.py --port <USB-port-with-ESP8266> write_flash 0x00000 <NodeMCU-firmware-directory>/bin/nodemcu_[integer|float]_<Git-branch>.bin

Don't leave comments on Docker Hub that are intended to be support requests. First, Docker Hub doesn't notify me when you write them, second I can't properly reply and third even if I could often it doesn't make much sense to keep them around forever and a day. Instead ask a question on StackOverflow and assign the nodemcu and docker tags.

For bugs and improvement suggestions create an issue at https://github.com/marcelstoer/docker-nodemcu-build/issues.

Thanks to Paul Sokolovsky who created and maintains esp-open-sdk.

http://frightanic.com