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docs/library: Update documentation of esp32's RMT.

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This explains how looping now works, and removes the warning about calling
wait_done().
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Jonathan Hogg 2020-07-03 14:14:33 +01:00 committed by Damien George
parent 7dbef5377c
commit 5f0e9d1bac
1 changed files with 19 additions and 8 deletions
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docs/library/esp32.rst
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@ -209,19 +209,21 @@ For more details see Espressif's `ESP-IDF RMT documentation.
.. method:: RMT.wait_done(timeout=0)
Returns True if `RMT.write_pulses` has completed.
Returns ``True`` if the channel is currently transmitting a stream of pulses
started with a call to `RMT.write_pulses`.
If *timeout* (defined in ticks of ``source_freq / clock_div``) is specified
the method will wait for *timeout* or until `RMT.write_pulses` is complete,
returning ``False`` if the channel continues to transmit.
.. Warning::
Avoid using ``wait_done()`` if looping is enabled.
the method will wait for *timeout* or until transmission is complete,
returning ``False`` if the channel continues to transmit. If looping is
enabled with `RMT.loop` and a stream has started, then this method will
always (wait and) return ``False``.
.. method:: RMT.loop(enable_loop)
Configure looping on the channel, allowing a stream of pulses to be
indefinitely repeated. *enable_loop* is bool, set to True to enable looping.
Configure looping on the channel. *enable_loop* is bool, set to ``True`` to
enable looping on the *next* call to `RMT.write_pulses`. If called with
``False`` while a looping stream is currently being transmitted then the
current set of pulses will be completed before transmission stops.
.. method:: RMT.write_pulses(pulses, start)
@ -230,6 +232,15 @@ For more details see Espressif's `ESP-IDF RMT documentation.
resolution ``(1 / (source_freq / clock_div))``. *start* defines whether the
stream starts at 0 or 1.
If transmission of a stream is currently in progress then this method will
block until transmission of that stream has ended before beginning sending
*pulses*.
If looping is enabled with `RMT.loop`, the stream of pulses will be repeated
indefinitely. Further calls to `RMT.write_pulses` will end the previous
stream - blocking until the last set of pulses has been transmitted -
before starting the next stream.
Ultra-Low-Power co-processor
----------------------------