词汇表

baremetal

没有 (成熟) 操作系统的系统,例如 MCU 基系统。当在 baremetal (裸机) 系统上运行时,MicroPython 的功能类似于小型操作系统,可运行用户程序并提供命令解释 ( REPL ).

缓冲协议

任何可以被自动转换为字节的 Python 对象,譬如 bytes , bytearray , memoryview and str 对象,都有实现缓冲协议。

board

Typically this refers to a printed circuit board (PCB) containing a microcontroller and supporting components. MicroPython firmware is typically provided per-board, as the firmware contains both MCU-specific functionality but also board-level functionality such as drivers or pin names.

bytecode

A compact representation of a Python program that generated by compiling the Python source code. This is what the VM actually executes. Bytecode is typically generated automatically at runtime and is invisible to the user. Note that while CPython and MicroPython both use bytecode, the format is different. You can also pre-compile source code offline using the cross-compiler .

callee-owned tuple

This is a MicroPython-specific construct where, for efficiency reasons, some built-in functions or methods may re-use the same underlying tuple object to return data. This avoids having to allocate a new tuple for every call, and reduces heap fragmentation. Programs should not hold references to callee-owned tuples and instead only extract data from them (or make a copy).

CircuitPython

A variant of MicroPython developed by Adafruit Industries .

CPython

CPython is the reference implementation of the Python programming language, and the most well-known one. It is, however, one of many implementations (including Jython, IronPython, PyPy, and MicroPython). While MicroPython’s implementation differs substantially from CPython, it aims to maintain as much compatibility as possible.

cross-compiler

Also known as mpy-cross . This tool runs on your PC and converts a .py file containing MicroPython code into a .mpy file containing MicroPython bytecode. This means it loads faster (the board doesn’t have to compile the code), and uses less space on flash (the bytecode is more space efficient).

driver

实现对特定组件 (譬如:传感器或显示) 支持的 MicroPython 库。

FFI

Acronym for Foreign Function Interface. A mechanism used by the MicroPython Unix port to access operating system functionality. This is not available on baremetal ports.

filesystem

Most MicroPython ports and boards provide a filesystem stored in flash that is available to user code via the standard Python file APIs such as open() . Some boards also make this internal filesystem accessible to the host via USB mass-storage.

冻结模块

A Python module that has been cross compiled and bundled into the firmware image. This reduces RAM requirements as the code is executed directly from flash.

垃圾收集器

A background process that runs in Python (and MicroPython) to reclaim unused memory in the heap .

GPIO

General-purpose input/output. The simplest means to control electrical signals (commonly referred to as “pins”) on a microcontroller. GPIO typically allows pins to be either input or output, and to set or get their digital value (logical “0” or “1”). MicroPython abstracts GPIO access using the machine.Pin and machine.Signal 类。

GPIO port

A group of GPIO pins, usually based on hardware properties of these pins (e.g. controllable by the same register).

heap

A region of RAM where MicroPython stores dynamic data. It is managed automatically by the 垃圾收集器 . Different MCUs and boards have vastly different amounts of RAM available for the heap, so this will affect how complex your program can be.

interned string

An optimisation used by MicroPython to improve the efficiency of working with strings. An interned string is referenced by its (unique) identity rather than its address and can therefore be quickly compared just by its identifier. It also means that identical strings can be de-duplicated in memory. String interning is almost always invisible to the user.

MCU

微控制器。微控制器通常比台式机、笔记本或电话拥有更少的资源,但其体积更小、价格更便宜,且需要更少的电力。MicroPython 被设计得很小,且经优化后足以在普通现代微控制器上运行。

micropython-lib

MicroPython is (usually) distributed as a single executable/binary file with just few builtin modules. There is no extensive standard library comparable with CPython ’s. Instead, there is a related, but separate project micropython-lib which provides implementations for many modules from CPython’s standard library.

Some of the modules are are implemented in pure Python, and are able to be used on all ports. However, the majority of these modules use FFI to access operating system functionality, and as such can only be used on the MicroPython Unix port (with limited support for Windows).

不像 CPython stdlib, micropython-lib modules are intended to be installed individually - either using manual copying or using upip .

MicroPython port

MicroPython 支持不同的 boards , RTOSes, and OSes, and can be relatively easily adapted to new systems. MicroPython with support for a particular system is called a “port” to that system. Different ports may have widely different functionality. This documentation is intended to be a reference of the generic APIs available across different ports (“MicroPython core”). Note that some ports may still omit some APIs described here (e.g. due to resource constraints). Any such differences, and port-specific extensions beyond the MicroPython core functionality, would be described in the separate port-specific documentation.

MicroPython Unix port

The unix port is one of the major MicroPython ports . It is intended to run on POSIX-compatible operating systems, like Linux, MacOS, FreeBSD, Solaris, etc. It also serves as the basis of Windows port. The Unix port is very useful for quick development and testing of the MicroPython language and machine-independent features. It can also function in a similar way to CPython ’s python 可执行文件。

.mpy file

The output of the cross-compiler . A compiled form of a .py file that contains MicroPython bytecode instead of Python source code.

native

Usually refers to “native code”, i.e. machine code for the target microcontroller (such as ARM Thumb, Xtensa, x86/x64). The @native decorator can be applied to a MicroPython function to generate native code instead of bytecode for that function, which will likely be faster but use more RAM.

port

缩写,通常指 MicroPython port ,但也可以参考 GPIO port .

.py file

包含 Python 源代码的文件。

REPL

An acronym for “Read, Eval, Print, Loop”. This is the interactive Python prompt, useful for debugging or testing short snippets of code. Most MicroPython boards make a REPL available over a UART, and this is typically accessible on a host PC via USB.

stream

Also known as a “file-like object”. A Python object which provides sequential read-write access to the underlying data. A stream object implements a corresponding interface, which consists of methods like read() , write() , readinto() , seek() , flush() , close() , etc. A stream is an important concept in MicroPython; many I/O objects implement the stream interface, and thus can be used consistently and interchangeably in different contexts. For more information on streams in MicroPython, see the io 模块。

UART

Acronym for “Universal Asynchronous Receiver/Transmitter”. This is a peripheral that sends data over a pair of pins (TX & RX). Many boards include a way to make at least one of the UARTs available to a host PC as a serial port over USB.

upip

(Literally, “micro pip”). A package manager for MicroPython, inspired by CPython ’s pip, but much smaller and with reduced functionality. upip runs both on the Unix port and on baremetal ports which offer filesystem and networking support.