MicroPython port to ESP8266

This is an experimental port of MicroPython for the WiFi modules based on Espressif ESP8266 chip.

WARNING: The port is experimental and many APIs are subject to change.

Supported features include:

• REPL (Python prompt) over UART0.
• Garbage collector, exceptions.
• Unicode support.
• Builtin modules: gc, array, collections, io, struct, sys, esp, network, many more.
• Arbitrary-precision long integers and 30-bit precision floats.
• WiFi support.
• Sockets using modlwip.
• GPIO and bit-banging I2C, SPI support.
• 1-Wire and WS2812 (aka Neopixel) protocols support.
• Internal filesystem using the flash.
• WebREPL over WiFi from a browser (clients at https://github.com/micropython/webrepl).
• Modules for HTTP, MQTT, many other formats and protocols via https://github.com/micropython/micropython-lib .

Work-in-progress documentation is available at http://docs.micropython.org/en/latest/esp8266/ .

Build instructions

The tool chain required for the build is the OpenSource ESP SDK, which can be found at https://github.com/pfalcon/esp-open-sdk. Clone this repository and run make in its directory to build and install the SDK locally. Make sure to add toolchain bin directory to your PATH. Read esp-open-sdk's README for additional important information on toolchain setup.

Add the external dependencies to the MicroPython repository checkout:

$ git submodule update --init

See the README in the repository root for more information about external dependencies.

The MicroPython cross-compiler must be built to pre-compile some of the built-in scripts to bytecode. This can be done using:

$ make -C mpy-cross

Then, to build MicroPython for the ESP8266, just run:

$ cd esp8266
$ make axtls
$ make

This will produce binary images in the build/ subdirectory. If you install MicroPython to your module for the first time, or after installing any other firmware, you should erase flash completely:

esptool.py --port /dev/ttyXXX erase_flash

Erase flash also as a troubleshooting measure, if a module doesn't behave as expected.

To flash MicroPython image to your ESP8266, use:

$ make deploy

This will use the esptool.py script to download the images. You must have your ESP module in the bootloader mode, and connected to a serial port on your PC. The default serial port is /dev/ttyACM0, flash mode is qio and flash size is detect (auto-detect based on Flash ID). To specify other values, use, eg (note that flash size is in megabits):

$ make PORT=/dev/ttyUSB0 FLASH_MODE=qio FLASH_SIZE=32m deploy

The image produced is build/firmware-combined.bin, to be flashed at 0x00000.

First start

Serial prompt

You can access the REPL (Python prompt) over UART (the same as used for programming).

• Baudrate: 115200

WiFi

Initally, the device configures itself as a WiFi access point (AP).

• ESSID: MicroPython-xxxxxx (x’s are replaced with part of the MAC address).
• Password: micropythoN (note the upper-case N).
• IP address of the board: 192.168.4.1.
• DHCP-server is activated.

WebREPL

Python prompt over WiFi, connecting through a browser.

• Hosted at http://micropython.org/webrepl.
• GitHub repository https://github.com/micropython/webrepl.

Please follow the instructions there.

More detailed instructions can be found at http://docs.micropython.org/en/latest/esp8266/esp8266/tutorial/intro.html

Troubleshooting

While the port is still in alpha, it's known to be generally stable. If you experience strange bootloops, crashes, lockups, here's a list to check against:

• You didn't erase flash before programming MicroPython firmware.
• Firmware can be occasionally flashed incorrectly. Just retry. Recent esptool.py versions have --verify option.
• Power supply you use doesn't provide enough power for ESP8266 or isn't stable enough.
• A module/flash may be defective (not unheard of for cheap modules).

Please consult dedicated ESP8266 forums/resources for hardware-related problems.