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From: Dennis Lee Bieber <wlfraed@ix.netcom.com>
Newsgroups: comp.lang.python
Subject: Re: How to XOR a byte output?
Date: Fri, 15 Apr 2016 08:06:45 -0400
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On Thu, 14 Apr 2016 23:05:03 +0000 (UTC), Chris Juried via Python-list
<python-list@python.org> declaimed the following:

>Hello list,
>I am new to the list and was wondering if anyone is using Python for MCU programing? In particular the 

	First matter: You should have created a new thread, rather than
piggy-backing on an existing thread. Your question has nothing to do with
the thread subject (XOR a byte).

>AVR and ARM based controllers. Is Python a plausible language for MCU programming or is C/C++ or Assembly the only way to go? Thanks in advance for your insight.

	Most implementations of Python are of a byte-code interpreted language.
It does not produce native executable binaries. That means that to use it
on those microcontrollers you would have to first port the interpreter to
the controller. That alone may consume the entire FLASH memory space --
even before you add library modules to access the hardware (Python doesn't
"do" hardware level access -- there is no "pointer to memory" you can set
to write to pins). The core of the interpreter, for 32-bit Windows, is
nearly 300KB -- more than the 256KB available on a TIVA TM4C123 Launchpad.
You'd then need to implement a file system so the interpreter could locate
and load library modules used by your program (not to mention the program
itself).

	At that point you've created the Python equivalent of the old Parallax
BASIC Stamp (in which the MCU FLASH is loaded with the interpreter of a
very limited BASIC, and off-chip memory is used to hold the pre-compiled
byte code of your program). Or the newer Parallax Propeller chip -- in
which the boot sequence loads a very short interpreter for the SPIN
language into the processor core from off-chip memory before it starts to
interpret byte-codes. Though unlike the BASIC Stamp, the Propeller also
gives you access to assembly (assembly programs get loaded into the core
memory instead of the interpreter -- so run much faster).

	You can run it (Python) on things like the BeagleBone Black and
Raspberry PI -- but those cards are using application SoC processors
running a form of Linux; they aren't running bare-bones direct hardware
access.

	For microcontrollers, you typically need to have a compiled language
that produces a memory image that can execute in place. It may not be C/C++
-- I believe a few efforts have been made for a no-run-time GNAT Ada to run
on some ARM devices.
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/