docs/library: Update documentation of esp32's RMT.
This explains how looping now works, and removes the warning about calling
wait_done().
@@ -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
----------------------------
