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docs/esp32: Fix machine.Timer quickref to specify HW timers. 

Also remove trailing spaces on other lines.
This commit is contained in:
Josh Lloyd 2020-07-20 11:06:12 +12:00 committed by Damien George
parent 47289f4bc9
commit fe7d47971f
1 changed files with 14 additions and 10 deletions
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24
docs/esp32/quickref.rst
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@ -118,17 +118,21 @@ Use the :mod:`time <utime>` module::
Timers
------
Virtual (RTOS-based) timers are supported. Use the :ref:`machine.Timer <machine.Timer>` class
with timer ID of -1::
The ESP32 port has four hardware timers. Use the :ref:`machine.Timer <machine.Timer>` class
with a timer ID from 0 to 3 (inclusive)::
from machine import Timer
tim = Timer(-1)
tim.init(period=5000, mode=Timer.ONE_SHOT, callback=lambda t:print(1))
tim.init(period=2000, mode=Timer.PERIODIC, callback=lambda t:print(2))
tim0 = Timer(0)
tim0.init(period=5000, mode=Timer.ONE_SHOT, callback=lambda t:print(0))
tim1 = Timer(1)
tim1.init(period=2000, mode=Timer.PERIODIC, callback=lambda t:print(1))
The period is in milliseconds.
Virtual timers are not currently supported on this port.
.. _Pins_and_GPIO:
Pins and GPIO
@ -172,7 +176,7 @@ PWM (pulse width modulation)
PWM can be enabled on all output-enabled pins. The base frequency can
range from 1Hz to 40MHz but there is a tradeoff; as the base frequency
*increases* the duty resolution *decreases*. See
*increases* the duty resolution *decreases*. See
`LED Control <https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/ledc.html>`_
for more details.
Currently the duty cycle has to be in the range of 0-1023.
@ -273,7 +277,7 @@ class::
.. Warning::
Currently *all* of ``sck``, ``mosi`` and ``miso`` *must* be specified when
initialising Software SPI.
initialising Software SPI.
Hardware SPI bus
----------------
@ -445,11 +449,11 @@ Use the ``TouchPad`` class in the ``machine`` module::
from machine import TouchPad, Pin
t = TouchPad(Pin(14))
t.read() # Returns a smaller number when touched
t.read() # Returns a smaller number when touched
``TouchPad.read`` returns a value relative to the capacitive variation. Small numbers (typically in
the *tens*) are common when a pin is touched, larger numbers (above *one thousand*) when
no touch is present. However the values are *relative* and can vary depending on the board
the *tens*) are common when a pin is touched, larger numbers (above *one thousand*) when
no touch is present. However the values are *relative* and can vary depending on the board
and surrounding composition so some calibration may be required.
There are ten capacitive touch-enabled pins that can be used on the ESP32: 0, 2, 4, 12, 13