Micropython + lvgl
To quickly run Micropython + LVGL from your web browser you can also use the Online Simulator.
For information abound Micropython lvgl bindings please refer to lv_binding_micropython/README.md
Original micropython README: https://github.com/micropython/micropython/blob/master/README.md
lv_micropython was created as an example of how to use lv_binding_micropython on a Micropython fork.
As such, we try to keep changes here as minimal as possible and we try to keep it in sync with Micropython upstream releases. We also try to add changes to
lv_binding_micropython instead of to
lv_micropython, when possible. (for example we keep all drivers in
lv_binding_micropython, the ESP32 CMake functionality etc.)
Eventually it turned out that many people prefer using
lv_micropython directly and only a few use it as a reference to support LVGL on their own Micropython fork.
If you are only starting with Micropython+LVGL, it's recommended that you use
lv_micropython, while porting a Micropython fork to LVGL is for advanced users.
First step is always to clone lv_micropython and update its submodules recursively:
git clone https://github.com/lvgl/lv_micropython.git cd lv_micropython git submodule update --init --recursive lib/lv_bindings
Next you should build mpy-cross
make -C mpy-cross
Port specific steps usually include updating the port's submodules with
make submodules and running make for the port itself.
Unix (Linux) port
sudo apt-get install build-essential libreadline-dev libffi-dev git pkg-config libsdl2-2.0-0 libsdl2-dev python3.8 parallelPython 3 is required, but you can install some other version of python3 instead of 3.8, if needed.
git clone https://github.com/lvgl/lv_micropython.git
git submodule update --init --recursive lib/lv_bindings
make -C mpy-cross
make -C ports/unix submodules
make -C ports/unix
esp-idf/export.sh from your ESP-IDF installation directory as explained in the Micropython ESP32 Getting Started documentation
ESP-IDF version needs to match Micropython expected esp-idf, otherwise a warning will be displayed (and build will probably fail) For more details refer to Setting up the toolchain and ESP-IDF
When using IL9341 driver, the color depth need to be set to match ILI9341. This can be done from the command line. Here is the command to build ESP32 + LVGL which is compatible with ILI9341 driver:
make -C mpy-cross make -C ports/esp32 LV_CFLAGS="-DLV_COLOR_DEPTH=16" BOARD=GENERIC_SPIRAM deploy
Explanation about the paramters:
LV_CFLAGSare used to override color depth, for ILI9341 compatibility.
LV_COLOR_DEPTH=16is needed if you plan to use the ILI9341 driver.
BOARD- I use WROVER board with SPIRAM. You can choose other boards from
deploy- make command will create ESP32 port of Micropython, and will try to deploy it through USB-UART bridge.
For more details please refer to Micropython ESP32 README.
Refer to the README of the
Raspberry Pi Pico port
This port uses Micropython infrastructure for C modules and
USER_C_MODULES must be given:
git clone https://github.com/lvgl/lv_micropython.git
git submodule update --init --recursive lib/lv_bindings
make -C ports/rp2 BOARD=PICO submodules
make -j -C mpy-cross
make -j -C ports/rp2 BOARD=PICO USER_C_MODULES=../../lib/lv_bindings/bindings.cmake
If you experience unstable behaviour, it is worth checking the value of MICROPY_HW_FLASH_STORAGE_BASE against the value of __flash_binary_end from the firmware.elf.map file. If the storage base is lower than the binary end, parts of the firmware will be overwritten when the micropython filesystem is initialised.
Super Simple Example
First, LVGL needs to be imported and initialized
import lvgl as lv lv.init()
Then display driver and input driver needs to be registered. Refer to Porting the library for more information. Here is an example of registering SDL drivers on Micropython unix port:
import SDL SDL.init() # Register SDL display driver. draw_buf = lv.disp_draw_buf_t() buf1_1 = bytearray(480*10) draw_buf.init(buf1_1, None, len(buf1_1)//4) disp_drv = lv.disp_drv_t() disp_drv.init() disp_drv.draw_buf = draw_buf disp_drv.flush_cb = SDL.monitor_flush disp_drv.hor_res = 480 disp_drv.ver_res = 320 disp_drv.register() # Regsiter SDL mouse driver indev_drv = lv.indev_drv_t() indev_drv.init() indev_drv.type = lv.INDEV_TYPE.POINTER indev_drv.read_cb = SDL.mouse_read indev_drv.register()
Here is an alternative example, for registering ILI9341 drivers on Micropython ESP32 port:
import lvgl as lv # Import ILI9341 driver and initialized it from ili9341 import ili9341 disp = ili9341() # Import XPT2046 driver and initalize it from xpt2046 import xpt2046 touch = xpt2046()
By default, both ILI9341 and XPT2046 are initialized on the same SPI bus with the following parameters:
miso=5, mosi=18, clk=19, cs=13, dc=12, rst=4, power=14, backlight=15, spihost=esp.HSPI_HOST, mhz=40, factor=4, hybrid=True
cs=25, spihost=esp.HSPI_HOST, mhz=5, max_cmds=16, cal_x0 = 3783, cal_y0 = 3948, cal_x1 = 242, cal_y1 = 423, transpose = True, samples = 3
You can change any of these parameters on ili9341/xpt2046 constructor. You can also initalize them on different SPI buses if you want, by providing miso/mosi/clk parameters. Set them to -1 to use existing (initialized) spihost bus.
Now you can create the GUI itself:
# Create a screen with a button and a label scr = lv.obj() btn = lv.btn(scr) btn.align_to(lv.scr_act(), lv.ALIGN.CENTER, 0, 0) label = lv.label(btn) label.set_text("Hello World!") # Load the screen lv.scr_load(scr)
More info about LVGL:
- Website https://lvgl.io
- GitHub: https://github.com/lvgl/lvgl
- Documentation: https://docs.lvgl.io/master/get-started/bindings/micropython.html
- Examples: https://docs.lvgl.io/master/examples.html
- More examples: https://github.com/lvgl/lv_binding_micropython/tree/master/examples
More info about lvgl Micropython bindings:
Discussions about the Micropython binding: lvgl/lvgl#557
More info about the unix port: https://github.com/micropython/micropython/wiki/Getting-Started#debian-ubuntu-mint-and-variants
The MicroPython project
This is the MicroPython project, which aims to put an implementation of Python 3.x on microcontrollers and small embedded systems. You can find the official website at micropython.org.
WARNING: this project is in beta stage and is subject to changes of the code-base, including project-wide name changes and API changes.
MicroPython implements the entire Python 3.4 syntax (including exceptions,
yield from, etc., and additionally
await keywords from
Python 3.5). The following core datatypes are provided:
basic Unicode support),
collections.namedtuple, classes and instances.
Builtin modules include
struct, etc. Select ports have
_thread module (multithreading). Note that only a subset of
Python 3 functionality is implemented for the data types and modules.
MicroPython can execute scripts in textual source form or from precompiled bytecode, in both cases either from an on-device filesystem or "frozen" into the MicroPython executable.
See the repository http://github.com/micropython/pyboard for the MicroPython board (PyBoard), the officially supported reference electronic circuit board.
Major components in this repository:
- py/ -- the core Python implementation, including compiler, runtime, and core library.
- mpy-cross/ -- the MicroPython cross-compiler which is used to turn scripts into precompiled bytecode.
- ports/unix/ -- a version of MicroPython that runs on Unix.
- ports/stm32/ -- a version of MicroPython that runs on the PyBoard and similar STM32 boards (using ST's Cube HAL drivers).
- ports/minimal/ -- a minimal MicroPython port. Start with this if you want to port MicroPython to another microcontroller.
- tests/ -- test framework and test scripts.
- docs/ -- user documentation in Sphinx reStructuredText format. Rendered HTML documentation is available at http://docs.micropython.org.
- ports/bare-arm/ -- a bare minimum version of MicroPython for ARM MCUs. Used mostly to control code size.
- ports/teensy/ -- a version of MicroPython that runs on the Teensy 3.1 (preliminary but functional).
- ports/pic16bit/ -- a version of MicroPython for 16-bit PIC microcontrollers.
- ports/cc3200/ -- a version of MicroPython that runs on the CC3200 from TI.
- ports/esp8266/ -- a version of MicroPython that runs on Espressif's ESP8266 SoC.
- ports/esp32/ -- a version of MicroPython that runs on Espressif's ESP32 SoC.
- ports/nrf/ -- a version of MicroPython that runs on Nordic's nRF51 and nRF52 MCUs.
- extmod/ -- additional (non-core) modules implemented in C.
- tools/ -- various tools, including the pyboard.py module.
- examples/ -- a few example Python scripts.
The subdirectories above may include READMEs with additional info.
"make" is used to build the components, or "gmake" on BSD-based systems.
You will also need bash, gcc, and Python 3.3+ available as the command
(if your system only has Python 2.7 then invoke make with the additional option
The MicroPython cross-compiler, mpy-cross
Most ports require the MicroPython cross-compiler to be built first. This program, called mpy-cross, is used to pre-compile Python scripts to .mpy files which can then be included (frozen) into the firmware/executable for a port. To build mpy-cross use:
$ cd mpy-cross $ make
The Unix version
The "unix" port requires a standard Unix environment with gcc and GNU make. x86 and x64 architectures are supported (i.e. x86 32- and 64-bit), as well as ARM and MIPS. Making full-featured port to another architecture requires writing some assembly code for the exception handling and garbage collection. Alternatively, fallback implementation based on setjmp/longjmp can be used.
To build (see section below for required dependencies):
$ cd ports/unix $ make submodules $ make
Then to give it a try:
$ ./micropython >>> list(5 * x + y for x in range(10) for y in [4, 2, 1])
CTRL-D (i.e. EOF) to exit the shell.
Learn about command-line options (in particular, how to increase heap size
which may be needed for larger applications):
$ ./micropython -h
Run complete testsuite:
$ make test
Unix version comes with a builtin package manager called upip, e.g.:
$ ./micropython -m upip install micropython-pystone $ ./micropython -m pystone
Building MicroPython ports may require some dependencies installed.
For Unix port,
libffi library and
pkg-config tool are required. On
Debian/Ubuntu/Mint derivative Linux distros, install
(includes toolchain and make),
Other dependencies can be built together with MicroPython. This may
be required to enable extra features or capabilities, and in recent
versions of MicroPython, these may be enabled by default. To build
these additional dependencies, in the port directory you're
interested in (e.g.
ports/unix/) first execute:
$ make submodules
This will fetch all the relevant git submodules (sub repositories) that the port needs. Use the same command to get the latest versions of submodules as they are updated from time to time. After that execute:
$ make deplibs
This will build all available dependencies (regardless whether they
are used or not). If you intend to build MicroPython with additional
options (like cross-compiling), the same set of options should be passed
make deplibs. To actually enable/disable use of dependencies, edit
ports/unix/mpconfigport.mk file, which has inline descriptions of the options.
For example, to build SSL module (required for
upip tool described above,
and so enabled by default),
MICROPY_PY_USSL should be set to 1.
For some ports, building required dependences is transparent, and happens
automatically. But they still need to be fetched with the
The STM32 version
The "stm32" port requires an ARM compiler, arm-none-eabi-gcc, and associated bin-utils. For those using Arch Linux, you need arm-none-eabi-binutils, arm-none-eabi-gcc and arm-none-eabi-newlib packages. Otherwise, try here: https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm
$ cd ports/stm32 $ make submodules $ make
You then need to get your board into DFU mode. On the pyboard, connect the 3V3 pin to the P1/DFU pin with a wire (on PYBv1.0 they are next to each other on the bottom left of the board, second row from the bottom).
Then to flash the code via USB DFU to your device:
$ make deploy
This will use the included
tools/pydfu.py script. If flashing the firmware
does not work it may be because you don't have the correct permissions, and
need to use
sudo make deploy.
See the README.md file in the ports/stm32/ directory for further details.
MicroPython is an open-source project and welcomes contributions. To be productive, please be sure to follow the Contributors' Guidelines and the Code Conventions. Note that MicroPython is licenced under the MIT license, and all contributions should follow this license.