MicroPython libraries¶
Warning
Important summary of this section
MicroPython provides built-in modules that mirror the functionality of the Python standard library (e.g.
os
,time
), as well as MicroPython-specific modules (e.g.bluetooth
,machine
).Most standard library modules implement a subset of the functionality of the equivalent Python module, and in a few cases provide some MicroPython-specific extensions (e.g.
array
,os
)Due to resource constraints or other limitations, some ports or firmware versions may not include all the functionality documented here.
To allow for extensibility, the built-in modules can be extended from Python code loaded onto the device.
This chapter describes modules (function and class libraries) which are built into MicroPython. This documentation in general aspires to describe all modules and functions/classes which are implemented in the MicroPython project. However, MicroPython is highly configurable, and each port to a particular board/embedded system may include only a subset of the available MicroPython libraries.
With that in mind, please be warned that some functions/classes in a module (or even the entire module) described in this documentation may be unavailable in a particular build of MicroPython on a particular system. The best place to find general information of the availability/non-availability of a particular feature is the “General Information” section which contains information pertaining to a specific MicroPython port.
On some ports you are able to discover the available, built-in libraries that can be imported by entering the following at the REPL:
help('modules')
Beyond the built-in libraries described in this documentation, many more modules from the Python standard library, as well as further MicroPython extensions to it, can be found in micropython-lib.
Python standard libraries and micro-libraries¶
The following standard Python libraries have been “micro-ified” to fit in with the philosophy of MicroPython. They provide the core functionality of that module and are intended to be a drop-in replacement for the standard Python library.
array
– arrays of numeric databinascii
– binary/ASCII conversionsbuiltins
– builtin functions and exceptionscmath
– mathematical functions for complex numberscollections
– collection and container typeserrno
– system error codesgc
– control the garbage collectorhashlib
– hashing algorithmsheapq
– heap queue algorithmio
– input/output streamsjson
– JSON encoding and decodingmath
– mathematical functionsos
– basic “operating system” servicesrandom
– generate random numbersre
– simple regular expressionsselect
– wait for events on a set of streamssocket
– socket modulessl
– SSL/TLS modulestruct
– pack and unpack primitive data typessys
– system specific functionstime
– time related functionsuasyncio
— asynchronous I/O schedulerzlib
– zlib decompression_thread
– multithreading support
MicroPython-specific libraries¶
Functionality specific to the MicroPython implementation is available in the following libraries.
bluetooth
— low-level Bluetoothbtree
– simple BTree databasecryptolib
– cryptographic ciphersframebuf
— frame buffer manipulationmachine
— functions related to the hardwaremicropython
– access and control MicroPython internalsneopixel
— control of WS2812 / NeoPixel LEDsnetwork
— network configurationuctypes
– access binary data in a structured waymutex
— mutex moduleuping
— Ping another computerurequests
— Related functions of HTTP client
Libraries specific to the OpenMV Cam¶
The following libraries are specific to the OpenMV Cam.
pyb
— functions related to the boardstm
— functionality specific to STM32 MCUssensor
— camera sensorimage
— machine visiontf
— Tensor Flowgif
— gif recordingmjpeg
— mjpeg recordingaudio
— Audio Modulemicro_speech
— Micro Speech Audio Module Examplelcd
— lcd driverfir
— thermal sensor driver (fir == far infrared)tv
— tv shield drivercpufreq
— CPU Frequency Controlbuzzer
— buzzer driverimu
— imu sensorrpc
— rpc libraryrtsp
— rtsp libraryomv
— OpenMV Cam Information
Third-party libraries on the OpenMV Cam¶
The following third-party libraries are built-in to your OpenMV Cam’s firmware:
ulab
— numpy-like array manipulation library¶
pid
— Proportional/Integral/Derivative Control¶
bno055
— IMU Driver¶
Examples scripts are located in OpenMV IDE under the IMU Shield
examples folder.
ssd1306
— OLED Driver¶
tb6612
— Stepper Motor Driver¶
Examples scripts are located in OpenMV IDE under the Motor Shield
examples folder.
lsm6dsox
— lsm6dsox Driver¶
modbus
— modbus protocol library¶
Examples scripts are located in OpenMV IDE under the Modbus
examples folder.
mqtt
— mqtt protocol library¶
Examples scripts are located in OpenMV IDE under the WiFi Shield
examples folder.
vl53l1x
— ToF Distance Sensor Driver¶
Examples scripts are located in OpenMV IDE under the Distance Shield
examples folder.
Extending built-in libraries from Python¶
In most cases, the above modules are actually named umodule
rather than
module
, but MicroPython will alias any module prefixed with a u
to the
non-u
version. However a file (or frozen module) named
module.py
will take precedence over this alias.
This allows the user to provide an extended implementation of a built-in library
(perhaps to provide additional CPython compatibility). The user-provided module
(in module.py
) can still use the built-in functionality by importing
umodule
directly. This is used extensively in micropython-lib. See
Package management for more information.
This applies to both the Python standard libraries (e.g. os
, time
, etc),
but also the MicroPython libraries too (e.g. machine
, bluetooth
, etc).
The main exception is the port-specific libraries (pyb
, esp
, etc).
Other than when you specifically want to force the use of the built-in module,
we recommend always using import module
rather than import umodule
.