Repository made for the SCHC Hackathon (IETF 102, Montreal)

• make (or make repos)
  • -> automatically clones schc-test (from Dominique)
  • -> automatically clones micropython (version for Linux)

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The sender/receiver code from schc-test had been copied/modified into a single file schc_test.py

Currently, the sender and the receivers can be run on Linux and communicate through lo (loopback), 127.0.0.1:9900 (sender) <-> 127.0.0.1:9999 (receiver)

How to run both:

• make recv

  • -> runs micropython with "schc_test.py recv"
  • This creates a receiver for fragments

• make send

  • -> runs micropython with "schc_test.py send"
  • This creates a sender for fragments which sends a large packet

Alternate with normal Python:

• make cpy-recv -> same as make recv by with normal python3 (CPython)
• make cpy-send -> same as make send by with normal python3 (CPython)

Alternate after make link

• make link-recv -> same as make recv but inside one directory generated by make link (see below)
• make link-send -> same as make send bur inside another directory generated by make link (see below)

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• make link
  • this creates a lots of links in project-X/ (where X=sending, receiving), the idea is that each project-X/ repository can be synchronized with a different pycom
  • By default devices are /dev/ttyACM0 /dev/ttyACM1, can change by adding a Makefile.local with

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Notes: micropython issues:

In micropython, bytearray accepts only one argument, whereas in cpython you must have 2 arguments (e.g. with the encoding), if the first is a str.

$ ./micropython/ports/unix/micropython -c 'bytearray("aaa", "utf-8")'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: function expected at most 1 arguments, got 2

$ python3 -c 'bytearray("aaa", "utf-8")'
$ # fine

There are many others:

• Globally, micropython for unix defines some version of modules with other names like "uXXX", e.g. usocket instead of socket, utime for time, etc.
• micropython for Pycom however, in many cases, keeps the correct names, or implement missing modules