It's more common to need non-blocking behaviour when reading from a UART,
rather than having a large timeout like 1000ms (the original behaviour).
With a large timeout it's 1) likely that the function will read forever if
characters keep trickling it; or 2) the function will unnecessarily wait
when characters come sporadically, eg at a REPL prompt.
This system makes it a lot easier to include external libraries as static,
native modules in MicroPython. Simply pass USER_C_MODULES (like
FROZEN_MPY_DIR) as a make parameter.
This is only correct for the extmod/uos_dupterm.c implementation however,
as e.g cc3200 implementation does the mp_load_method() itself, and anyway
requires `read` instead of `readinto`.
Replaces "PYB: soft reboot" with "MPY: soft reboot", etc.
Having a consistent prefix across ports reduces the difference between
ports, which is a general goal. And this change won't break pyboard.py
because that tool only looks for "soft reboot".
The machine.sleep() function can be misleading because it clashes with
time.sleep() which has quite different semantics. So change it to
machine.lightsleep() which shows that it is closer in behaviour to
machine.deepsleep().
Also, add an optional argument to these two sleep functions to specify a
maximum time to sleep for. This is a common operation and underlying
hardware usually has a special way of performing this operation.
The existing machine.sleep() function will remain for backwards
compatibility purposes, and it can simply be an alias for
machine.lightsleep() without arguments. The behaviour will be the same.
Examples are added to the beginning of the module docs, similarly to docs
for many other modules.
Improvements to grammar, style, and clarity. Some paragraphs are updated
with better suggestions. A warning added of the effect incorrect usage of
the module may have. Describe the fact that offset range used in one
defined structure is limited.
Otherwise there is really nothing that can be done, it can't be unlocked by
the user because there is no way to allocate memory to execute the unlock.
See issue #4205 and #4209.
