board
=====

.. py:module:: board

.. autoapi-nested-parse::

   Pin assignments and bus setup for the Adafruit Feather ESP32-S3.

   This is the only module besides the entry points that touches `machine`,
   so everything else can be tested on the host.



Attributes
----------

.. autoapisummary::

   board.I2C_POWER_PIN
   board.SDA_PIN
   board.SCL_PIN
   board.I2C_FREQ
   board.EPD_SCK_PIN
   board.EPD_MOSI_PIN
   board.EPD_CS_PIN
   board.EPD_DC_PIN
   board.EPD_RST_PIN
   board.EPD_BUSY_PIN
   board.EPD_PWR_PIN
   board.EPD_SPI_BAUDRATE
   board.NEOPIXEL_POWER_PIN
   board.USB_PRESENT_VOLTS


Functions
---------

.. autoapisummary::

   board.init_i2c
   board.init_display
   board.status_screen
   board.hold_pins_for_sleep
   board.usb_volts
   board.usb_power
   board.wake_on_usb


Module Contents
---------------

.. py:data:: I2C_POWER_PIN
   :value: 7


.. py:data:: SDA_PIN
   :value: 3


.. py:data:: SCL_PIN
   :value: 4


.. py:data:: I2C_FREQ
   :value: 100000


.. py:data:: EPD_SCK_PIN
   :value: 36


.. py:data:: EPD_MOSI_PIN
   :value: 35


.. py:data:: EPD_CS_PIN
   :value: 10


.. py:data:: EPD_DC_PIN
   :value: 9


.. py:data:: EPD_RST_PIN
   :value: 6


.. py:data:: EPD_BUSY_PIN
   :value: 5


.. py:data:: EPD_PWR_PIN
   :value: 11


.. py:data:: EPD_SPI_BAUDRATE
   :value: 4000000


.. py:function:: init_i2c()

   Switch on I2C power and return the bus.


.. py:function:: init_display()

   Return the e-paper driver (not yet initialised, see EPD.init).


.. py:function:: status_screen()

   Return a `statusscreen.StatusScreen` on the display.


.. py:data:: NEOPIXEL_POWER_PIN
   :value: 21


.. py:function:: hold_pins_for_sleep(display_powered=True)

   Hold pin levels during deep sleep, where they would float otherwise.

   The display stays powered with its control lines inactive or, if it is
   switched off, all its lines are held low so that the module is not fed
   through its inputs. The NeoPixel supply is switched off.

   :param display_powered: Whether the display keeps its supply in sleep.


.. py:data:: USB_PRESENT_VOLTS
   :value: 4.0


.. py:function:: usb_volts(pin, divider)

   Measure the USB supply through a divider on `pin`.

   :param pin: GPIO of the divider, or None if none is wired
               (`defaults.USB_SENSE_PIN`).
   :param divider: Ratio of the divider (`defaults.USB_SENSE_DIVIDER`).

   :returns: The USB voltage in volts, or None without a divider.


.. py:function:: usb_power(pin, divider)

   Tell whether USB power is present: True, False, or None without a divider.


.. py:function:: wake_on_usb(pin)

   Wake from deep sleep once USB power reaches the divider on `pin`.

   The wake is level-triggered, so only arm it while USB is absent. The
   divided voltage must count as high for the pin (about 2.5 V and up).