diff options
Diffstat (limited to 'docs/esp32')
| -rw-r--r-- | docs/esp32/quickref.rst | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/docs/esp32/quickref.rst b/docs/esp32/quickref.rst index b4f443a910..d5c222f3a1 100644 --- a/docs/esp32/quickref.rst +++ b/docs/esp32/quickref.rst @@ -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 |