Author: mfm

A prebuild toolchain for the ESP32 is available from Espressif: https://dl.espressif.com/dl/xtensa-esp32-elf-osx-1.22.0-80-g6c4433a-5.2.0.tar.gz

If you’re interested in building from scratch check the docs for IDF v.3.3 https://docs.espressif.com/projects/esp-idf/en/v3.3/get-started/macos-setup.html

Get MicroPython and initialise its dependencies

git clone https://github.com/micropython/micropython.git
git submodule update --init

Get the correct version of the IDF and its dependencies

As of 09/2019 the MicroPython build needs v3.3 of the IDF. Later versions use cmake instead of make.

git clone https://github.com/espressif/esp-idf.git
git checkout 6ccb4cf5b7d1fdddb8c2492f9cbc926abaf230df
git submodule update --init --recursive

Unpack the toolchain and add IT to the PATH

tar -zxf xtensa-esp32-elf-osx-1.22.0-80-g6c4433a-5.2.0.tar.gz
export PATH=$PATH:<replace with absolute path to toolchain>/bin

Virtual Environment

Some of the build tools and dependencies require Python 3. Lets create a virtual environment and activate it to keep things separated.

virtualenv --python=python3 esp32buildEnv
source esp32buildEnv/bin/activate

Install the python dependencies required by the IDF

pip install -r esp-idf/requirements.txt

Build the crosscompiler

cd mpy-cross
make

Build the ESP32 port

cd ports/esp32
ESPIDF=<path to IDF root> PYTHON2=/usr/bin/python make  

The resulting “firmware.bin” can be uploaded to your ESP32 with the “esptool” as usual.