189 lines
6.6 KiB
Markdown
189 lines
6.6 KiB
Markdown
MicroPython port to ESP8266
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===========================
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This is an experimental port of MicroPython for the WiFi modules based
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on Espressif ESP8266 chip.
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WARNING: The port is experimental and many APIs are subject to change.
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Supported features include:
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- REPL (Python prompt) over UART0.
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- Garbage collector, exceptions.
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- Unicode support.
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- Builtin modules: gc, array, collections, io, struct, sys, esp, network,
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many more.
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- Arbitrary-precision long integers and 30-bit precision floats.
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- WiFi support.
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- Sockets using modlwip.
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- GPIO and bit-banging I2C, SPI support.
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- 1-Wire and WS2812 (aka Neopixel) protocols support.
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- Internal filesystem using the flash.
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- WebREPL over WiFi from a browser (clients at https://github.com/micropython/webrepl).
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- Modules for HTTP, MQTT, many other formats and protocols via
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https://github.com/micropython/micropython-lib .
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Documentation is available at http://docs.micropython.org/en/latest/esp8266/quickref.html.
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Build instructions
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------------------
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You need the esp-open-sdk toolchain (which provides both the compiler and libraries), which
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you can obtain using one of the following two options:
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- Use a Docker image with a pre-built toolchain (**recommended**).
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To use this, install Docker, then prepend
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`docker run --rm -v $HOME:$HOME -u $UID -w $PWD larsks/esp-open-sdk ` to the start
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of the mpy-cross and firmware `make` commands below. This will run the commands using the
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toolchain inside the container but using the files on your local filesystem.
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- or, install the esp-open-sdk directly on your PC, which can be found at
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<https://github.com/pfalcon/esp-open-sdk>. Clone this repository and
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run `make` in its directory to build and install the SDK locally. Make sure
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to add toolchain bin directory to your PATH. Read esp-open-sdk's README for
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additional important information on toolchain setup.
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If you use this approach, then the command below will work exactly.
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Add the external dependencies to the MicroPython repository checkout:
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```bash
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$ make -C ports/esp8266 submodules
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```
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See the README in the repository root for more information about external
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dependencies.
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The MicroPython cross-compiler must be built to pre-compile some of the
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built-in scripts to bytecode. This can be done using:
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```bash
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$ make -C mpy-cross
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```
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(Prepend the Docker command if using Docker, see above)
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Then, to build MicroPython for the ESP8266, just run:
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```bash
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$ cd ports/esp8266
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$ make
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```
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(Prepend the Docker command if using Docker, see above)
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This will produce binary images in the `build-GENERIC/` subdirectory. If you
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install MicroPython to your module for the first time, or after installing any
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other firmware, you should erase flash completely:
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```bash
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$ esptool.py --port /dev/ttyXXX erase_flash
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```
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You can install esptool.py either from your system package manager or from PyPi.
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Erasing the flash is also useful as a troubleshooting measure, if a module doesn't
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behave as expected.
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To flash MicroPython image to your ESP8266, use:
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```bash
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$ make deploy
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```
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(This should not be run inside Docker as it will need access to the serial port.)
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This will use the `esptool.py` script to download the images. You must have
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your ESP module in the bootloader mode, and connected to a serial port on your PC.
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The default serial port is `/dev/ttyACM0`, flash mode is `qio` and flash size is
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`detect` (auto-detect based on Flash ID).
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To specify other values for `esptool.py`, use, e.g.:
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```bash
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$ make PORT=/dev/ttyUSB0 FLASH_MODE=qio FLASH_SIZE=32m deploy
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```
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(note that flash size is in megabits)
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If you want to flash manually using `esptool.py` directly, the image produced is
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`build-GENERIC/firmware-combined.bin`, to be flashed at 0x00000.
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The default board definition is the directory `boards/GENERIC`.
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For a custom configuration you can define your own board in the directory `boards/`.
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The `BOARD` variable can be set on the make command line, for example:
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```bash
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$ make BOARD=GENERIC_512K
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```
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__512KB FlashROM version__
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The normal build described above requires modules with at least 1MB of FlashROM
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onboard. There's a special configuration for 512KB modules, which can be
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built with `make BOARD=GENERIC_512K`. This configuration is highly limited, lacks
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filesystem support, WebREPL, and has many other features disabled. It's mostly
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suitable for advanced users who are interested to fine-tune options to achieve a
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required setup. If you are an end user, please consider using a module with at
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least 1MB of FlashROM.
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First start
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-----------
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Be sure to change ESP8266's WiFi access point password ASAP, see below.
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__Serial prompt__
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You can access the REPL (Python prompt) over UART (the same as used for
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programming).
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- Baudrate: 115200
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Run `help()` for some basic information.
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__WiFi__
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Initially, the device configures itself as a WiFi access point (AP).
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- ESSID: MicroPython-xxxxxx (x’s are replaced with part of the MAC address).
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- Password: micropythoN (note the upper-case N).
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- IP address of the board: 192.168.4.1.
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- DHCP-server is activated.
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- Please be sure to change the password to something non-guessable
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immediately. `help()` gives information how.
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__WebREPL__
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Python prompt over WiFi, connecting through a browser.
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- Hosted at http://micropython.org/webrepl.
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- GitHub repository https://github.com/micropython/webrepl.
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Please follow the instructions there.
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__upip__
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The ESP8266 port comes with builtin `upip` package manager, which can
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be used to install additional modules (see the main README for more
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information):
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```
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>>> import upip
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>>> upip.install("micropython-pystone_lowmem")
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[...]
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>>> import pystone_lowmem
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>>> pystone_lowmem.main()
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```
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Downloading and installing packages may requite a lot of free memory,
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if you get an error, retry immediately after the hard reset.
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Documentation
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-------------
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More detailed documentation and instructions can be found at
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http://docs.micropython.org/en/latest/esp8266/ , which includes Quick
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Reference, Tutorial, General Information related to ESP8266 port, and
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to MicroPython in general.
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Troubleshooting
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---------------
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While the port is in beta, it's known to be generally stable. If you
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experience strange bootloops, crashes, lockups, here's a list to check against:
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- You didn't erase flash before programming MicroPython firmware.
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- Firmware can be occasionally flashed incorrectly. Just retry. Recent
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esptool.py versions have --verify option.
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- Power supply you use doesn't provide enough power for ESP8266 or isn't
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stable enough.
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- A module/flash may be defective (not unheard of for cheap modules).
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Please consult dedicated ESP8266 forums/resources for hardware-related
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problems.
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Additional information may be available by the documentation links above.
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