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docs: Update I2C and SPI docs to add reference to SoftI2C and SoftSPI.

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Signed-off-by: Damien George <damien@micropython.org>
This commit is contained in:
Damien George
2020-09-29 16:50:23 +10:00
parent 71f3ade770
commit 98182a97c5
4 changed files with 89 additions and 40 deletions
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62
docs/esp32/quickref.rst
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@@ -249,16 +249,15 @@ ESP32 specific ADC class method reference:
Software SPI bus
----------------
There are two SPI drivers. One is implemented in software (bit-banging)
and works on all pins, and is accessed via the :ref:`machine.SPI <machine.SPI>`
class::
Software SPI (using bit-banging) works on all pins, and is accessed via the
:ref:`machine.SoftSPI <machine.SoftSPI>` class::
from machine import Pin, SPI
from machine import Pin, SoftSPI
# construct an SPI bus on the given pins
# construct a SoftSPI bus on the given pins
# polarity is the idle state of SCK
# phase=0 means sample on the first edge of SCK, phase=1 means the second
spi = SPI(baudrate=100000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4))
spi = SoftSPI(baudrate=100000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4))
spi.init(baudrate=200000) # set the baudrate
@@ -298,39 +297,54 @@ mosi 13 23
miso 12 19
===== =========== ============
Hardware SPI has the same methods as Software SPI above::
Hardware SPI is accessed via the :ref:`machine.SPI <machine.SPI>` class and
has the same methods as software SPI above::
from machine import Pin, SPI
hspi = SPI(1, 10000000, sck=Pin(14), mosi=Pin(13), miso=Pin(12))
vspi = SPI(2, baudrate=80000000, polarity=0, phase=0, bits=8, firstbit=0, sck=Pin(18), mosi=Pin(23), miso=Pin(19))
Software I2C bus
----------------
I2C bus
-------
Software I2C (using bit-banging) works on all output-capable pins, and is
accessed via the :ref:`machine.SoftI2C <machine.SoftI2C>` class::
The I2C driver has both software and hardware implementations, and the two
hardware peripherals have identifiers 0 and 1. Any available output-capable
pins can be used for SCL and SDA. The driver is accessed via the
:ref:`machine.I2C <machine.I2C>` class::
from machine import Pin, SoftI2C
from machine import Pin, I2C
i2c = SoftI2C(scl=Pin(5), sda=Pin(4), freq=100000)
# construct a software I2C bus
i2c = I2C(scl=Pin(5), sda=Pin(4), freq=100000)
i2c.scan() # scan for devices
# construct a hardware I2C bus
i2c = I2C(0)
i2c = I2C(1, scl=Pin(5), sda=Pin(4), freq=400000)
i2c.scan() # scan for slave devices
i2c.readfrom(0x3a, 4) # read 4 bytes from slave device with address 0x3a
i2c.writeto(0x3a, '12') # write '12' to slave device with address 0x3a
i2c.readfrom(0x3a, 4) # read 4 bytes from device with address 0x3a
i2c.writeto(0x3a, '12') # write '12' to device with address 0x3a
buf = bytearray(10) # create a buffer with 10 bytes
i2c.writeto(0x3a, buf) # write the given buffer to the slave
Hardware I2C bus
----------------
There are two hardware I2C peripherals with identifiers 0 and 1. Any available
output-capable pins can be used for SCL and SDA but the defaults are given
below.
===== =========== ============
\ I2C(0) I2C(1)
===== =========== ============
scl 18 25
sda 19 26
===== =========== ============
The driver is accessed via the :ref:`machine.I2C <machine.I2C>` class and
has the same methods as software I2C above::
from machine import Pin, I2C
i2c = I2C(0)
i2c = I2C(1, scl=Pin(5), sda=Pin(4), freq=400000)
Real time clock (RTC)
---------------------