Hub SDK Programming
============================================

Programming Language
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The Hub is based on MicroPython.

MicroPython is a lean and efficient implementation of the Python 3 programming language that includes a small subset of the Python standard library and is optimized to run on microcontrollers and in constrained environments.

MicroPython is packed full of advanced features such as an interactive prompt, arbitrary precision integer, closures, list comprehension, generators, exception handling, and more. Yet it is compact enough to fit and run within just 256k of code space and 16k of RAM.

MicroPython aims to be as compatible with standard Python as possible to allow you to transfer code with ease from the desktop to a microcontroller or embedded system.

For details about MicroPython, visit: https://micropython.org

Memory Limits
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Unlike usual design, SyncSign Hub provides up to 4MB RAM, enough for complex programming like TLS secure transfer.

The flash storage accessible from MicroPython is 256KB, which stores around 50 files (size in 4KB each). It's the non-volatile storage, and will not get lost after reboot or power failure. We use it to save customized user application and runtime configuration.

Libs
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Hub SDK provides basic libs, especially PAN access, and Renderer. see :doc:`../references/hub` for details.

For more libs that run on Hub, see https://github.com/micropython/micropython-lib for details.

Download SDK
-----------------------

We provide a host-based simulator that runs on x86 macOS/Linux, along with the latest SDK libs built-in.

See :doc:`Simulator <../samples/simulator>` for details.