Behaviour was changed from stack to queue in
8977c7eb58, and this updates variable names
to match. Also updates other references (docs, error messages).
This allows to efficiently send to an I2C slave data that is made up of
more than one buffer. Instead of needing to allocate temporary memory to
combine buffers together this new method allows to pass in a tuple or list
of buffers. The name is based on the POSIX function writev() which has
similar intentions and signature.
The reasons for taking this approach (compared to having an interface with
separate start/write/stop methods) are:
- It's a backwards compatible extension.
- It's convenient for the user.
- It's efficient because there is only one Python call, then the C code can
do everything in one go.
- It's efficient on the I2C bus because the implementation can do
everything in one go without pauses between blocks of bytes.
- It should be possible to implement this extension in all ports, for
hardware and software I2C.
Further discussion is found in issue #3482, PR #4020 and PR #4763.
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 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`.
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.
All concrete network classes are now moved to their own file (eg
network.WLAN.rst) and deconditionalised (remove ..only:: directives). This
makes the network documentation the same for all ports. After this change
there are no more "..only::" directives for different ports, and the only
difference among ports is the very front page of the docs.
The WiPy machine.Timer class is very different to the esp8266 and esp32
implementations which are better candidates for a general Timer class. By
moving the WiPy Timer docs to a completely separate file, under a new name
machine.TimerWiPy, it gives a clean slate to define and write the docs for
a better, general machine.Timer class. This is with the aim of eventually
providing documentation that does not have conditional parts to it,
conditional on the port.
While the new docs are being defined it makes sense to keep the WiPy docs,
since they describe its behaviour. Once the new Timer behaviour is defined
the WiPy code can be changed to match it, and then the TimerWiPy docs would
be removed.
The machine module should be standard across all ports so should have the
same set of classes in the docs. A special warning is added to the top of
the machine.SD class because it is not standardised and only available on
the cc3200 port.
It's fair to just provide a link to all available modules, regardless of
the port. Most of the existing ports (unix, stm32, esp8266, esp32) share
most of the same set of modules anyway, so no need to maintain separate
lists for them. And there's a big discussion at the start of this index
about modules not being available on a given port.
For port-specific modules, they can also be listed unconditionally because
they have headings that explicitly state they are only available on certain
ports.
The UART.init() method is now included unconditionally and its wording
adjusted to better describe ports other than the cc3200.
UART.irq() is also included unconditionally, but this is currently only
available on the WiPy target.
By virtue of its name, the pyb module would only be available on a pyboard
and so does not need to have conditional "only" directives throughout its
documentation.
These conditionals were added mostly in
cfcf47c064 in the initial development of the
cc3200 port, which had the pyb module before it switched to the machine
module. And wipy only conditionals were removed from the pyb module
documentation in 4542643025, so there's no
need to retain any more conditionals.
Allow including crypto consts based on compilation settings. Disabled by
default to reduce code size; if one wants extra code readability, can
enable them.
These can be optionally specified, but all ports are expected to be able to
accept them, at the very least ignore, though handling of "type" param
(SOCK_STREAM vs SOCK_DGRAM) is recommended.
This can be used to select the output buffer behaviour of the DAC. The
default values are chosen to retain backwards compatibility with existing
behaviour.
Thanks to @peterhinch for the initial idea to add this feature.
The parameter order in the example for ticks_diff was incorrect. If it's
"too early" that means that scheduled time is greater than current time and
if it's "running late" then scheduled time would be less than current time.
Put offset first in OR expressions, and use "offset" var instead of
hardcoded numbers. Hopefully, this will make it more self-describing
and show patterns better.
Describe that the only portable way to deal with addresses is by using
getaddrinfo(). Describe that some ports may support tuple addresses using
"socket" module (vs "usocket" of native MicroPython).
This clarifies return values and the handling of invalid (e.g. newline)
characters.
Encoding conforms to RFC 3548, but decoding does not, as it ignores invalid
characters in base64 input. Instead, it conforms to MIME handling of base64
(RFC 2045).
Note that CPython doesn't document handling of invalid characters in
a2b_base64() docs:
https://docs.python.org/3/library/binascii.html#binascii.a2b_base64 , so
we specify it more explicitly than it, based on CPython's actual behavior
(with which MicroPython now compliant).
The old intro talked about "differences", but there were hardly any
sections describing differences, mostly MicroPython specific features.
On the other hand, we now have real "differences" chapter, though it's
mostly concerned with stdlib differences.
So, try to avoid confusion by changing wording and linking to the other
chapters and contrasting them with what is described in "MicroPython
language".
This adds description of implied AbstractNIC base class, which should be
"subclasses" and implemented by a particular network device class.
This is just an initial step in that direction, the API and description
will be elabotated further.
The list starts with the simplest functionality - GPIO, proceeds to
communication interfaces (UART, SPI, I2C), the to time(r) related
things, then everything else.
For a couple of ports, there was information which directory is set
as current after boot. This information doesn't belong to "uos" module,
and is moved to boards' references (which actually already contained
information on which directory is chosen for boot, even if without
explicit mentioning that it becomes current directory, which is now
done).
This method isn't implemented in any port. It seemed to have originated
in cc3200 port, but actually never was implemented there either. In
general case, it's impossible to implement this method (for example, for
a perfect GPO, which has only output latch without any feedback look
into a CPU).
Both aren't part of generic Hardware API: It's impossible to implement
.id() method in a generic case (e.g., when Pin is instantiated by the
underlying OS/RTOS). .board attribute is an obvious space hog which
instead can be implemented on Python level if needed.
MONO_xxx is much easier to read if you're not familiar with the code.
MVLSB is deprecated but kept for backwards compatibility, for the time
being.
This patch also updates the associated docs and tests.
* Fix mis-spelling of `ticks_add` in code examples.
* Be consistent about parentheses after function names.
* Be consistent about formatting of function, variable and constant names.
* Be consistent about spaces and punctuation.
* Fix some language errors (missing or wrong words, wrong word order).
* Keep line length under 90 chars.
Signed-off-by: Christopher Arndt <chris@chrisarndt.de>
MicroPython guarantees '/' to be a path separator, so extra constant taking
precious ROM space are not needed. MicroPython never had such constant, only
one vendor port had it (now unmaintained).
This new function controls what happens on a hard-fault:
- debugging disabled: board will do a reset
- debugging enabled: board will print registers and stack and flash LEDs
The default is disabled, ie to do a reset. This is different to previous
behaviour which flashed the LEDs and waited indefinitely.
machine.time_pulse_us() is intended to provide very fine timing, including
while working with signal bursts, where each transition is tracked in row.
Throwing and handling an exception may take too much time and "signal loss".
So instead, in case of a timeout, just return negative value. Cases of
timeout while waiting for initial signal stabilization, and during actual
timing, are recognized.
The documentation is updated accordingly, and rewritten somewhat to clarify
the function behavior.
New keyword option in constructor and init() method is "dma=<bool>".
DMA is now disabled by default for I2C transfers because it currently does
not handle I2C bus errors very well (eg if slave device doesn't ACK or
NACK correctly during a transfer).
It's mandatory function which should be present in every port. Even if
it's not, in the stdlib intro we waarn users that a particular port can
lack anything of described in the docs.
Clarify the class implements master side of the protocol, also put adhoc
WiPy paramter after the generic, described in the current Hardware API
version.
The memory read/write I2C functions now take an optional keyword-only
parameter that specifies the number of bits in the memory address.
Only mem-addrs that are a multiple of 8-bits are supported (otherwise
the behaviour is undefined).
Due to the integer type used for the address, for values larger than 32
bits, only 32 bits of address will be sent, and the rest will be padded
with 0s. Right now no exception is raised when that happens. For values
smaller than 8, no address is sent. Also no exception then.
Tested with a VL6180 sensor, which has 16-bit register addresses.
Due to code refactoring, this patch reduces stmhal and esp8266 builds
by about 50 bytes.
