esp-32 Build Environment

This Dockerfile contains the dependencies necessary to build and flash programs for the ESP32 chip.

Dependencies

• Docker
• Virtualbox (if you're not on Linux)

Quick Setup

• docker pull bschwind/esp-32-build
• cd to your esp-32 project
• Without USB flashing support: docker run --rm -it -v $(PATH_TO_ESP_IDF):/esp/esp-idf -v $(PATH_TO_YOUR_PROJECT):/esp/project bschwind/esp-32-build /bin/bash
• With USB flashing support: docker run --rm -it --privileged -v /dev/bus/usb:/dev/bus/usb -v $(PATH_TO_ESP_IDF):/esp/esp-idf -v $(PATH_TO_YOUR_PROJECT):/esp/project bschwind/esp-32-build /bin/bash

Either step will put you in an interactive shell inside the container. If you have a Makefile in your project directory, you can immediately run make and your source should get compiled. make flash will attempt to flash the code to /dev/ttyUSB0.

Flashing Images from the Container

If you're on docker-machine (OS X or Windows), you need to forward your USB device within Virtualbox. This is best managed in the VirtualBox GUI.

Steps:

• Stop your docker virtual machine host, if applicable
• Plug in the USB serial device you will use to flash to the ESP8266
• Install virtualbox extensions to support USB (Ctrl-F "extension" on that page)
  • OS X -> Under "Virtualbox" -> Preferences, go to the Extensions tab
  • Windows -> Same thing?
  • Click the "Adds new package" button and select the extension pack you downloaded
• Return to the main VirtualBox GUI
• Right click on your docker VM and select "Settings"
• Select "Ports" -> "USB"
• Check the box "Enable USB Controller" and select "USB 2.0 (EHCI) Controller"
• Under "USB Device Filters" click the USB icon with the green plus sign to add a USB device
• Select your USB serial device (in my case it was "FTDI FT232R USB UART [0600]")
• Click OK until you're back to the main Virtualbox GUI
• At this point you can restart your virtual machine with docker-machine start <YOUR_DOCKER_VM_NAME>
• Run docker as we did in Quick Setup: docker run --rm -it --privileged -v /dev/bus/usb:/dev/bus/usb -v $(PWD):/esp/project bschwind/esp-32-build /bin/bash
  • NOTE: With the -v /dev/bus/usb:/dev/bus/usb volume, the /dev/bus/usb on the lefthand side of the colon refers to docker VM's USB directory, not your host machine (you likely won't find that path on OS X)
• /dev/ttyUSB0 should now be available
• Run make and then make flash on an example project or your own

If you're on Linux, it should be sufficient to share your USB device either as a docker volume or with the --device flag. However, I have not yet tested Linux.

Serial Debugging

Picocom is installed in this image by default. Invoke it with picocom -b 115200 /dev/ttyUSB0 (change the baud rate and device path accordingly)

Stop it with Ctrl-A Ctrl-X

PRO TIP

You can change the baud rate and other properties with make menuconfig which will drop you in esp-idf's project configuration menu. I recommend selecting a baud rate of 921600 as it will reduce flashing times to around 4-5 seconds.

Using ccache

• docker pull bschwind/esp-32-build
• cd to your esp-32 project
• create the ccache persistent directory docker create -v /mnt/ccache:/ccache --name ccache bschwind/esp-32-build
• docker run --rm -it -v $(PATH_TO_ESP_IDF):/esp/esp-idf -v $(PATH_TO_YOUR_PROJECT):/esp/project -e CCACHE_DIR=/ccache --volumes-from ccache bschwind/esp-32-build /bin/bash