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Diffstat (limited to 'docs/esp8266/quickref.rst')
| -rw-r--r-- | docs/esp8266/quickref.rst | 41 |
1 files changed, 28 insertions, 13 deletions
diff --git a/docs/esp8266/quickref.rst b/docs/esp8266/quickref.rst index 48543dfab6..d06fe5a6f1 100644 --- a/docs/esp8266/quickref.rst +++ b/docs/esp8266/quickref.rst @@ -23,14 +23,14 @@ Tab-completion is useful to find out what methods an object has. Paste mode (ctrl-E) is useful to paste a large slab of Python code into the REPL. -The ``machine`` module:: +The :mod:`machine` module:: import machine machine.freq() # get the current frequency of the CPU machine.freq(160000000) # set the CPU frequency to 160 MHz -The ``esp`` module:: +The :mod:`esp` module:: import esp @@ -40,7 +40,7 @@ The ``esp`` module:: Networking ---------- -The ``network`` module:: +The :mod:`network` module:: import network @@ -69,13 +69,13 @@ A useful function for connecting to your local WiFi network is:: pass print('network config:', wlan.ifconfig()) -Once the network is established the ``socket`` module can be used +Once the network is established the :mod:`socket <usocket>` module can be used to create and use TCP/UDP sockets as usual. Delay and timing ---------------- -Use the ``time`` module:: +Use the :mod:`time <utime>` module:: import time @@ -162,17 +162,18 @@ Use the ``machine.ADC`` class:: adc = ADC(0) # create ADC object on ADC pin adc.read() # read value, 0-1024 -SPI bus -------- +Software SPI bus +---------------- -The SPI driver is implemented in software and works on all pins:: +There are two SPI drivers. One is implemented in software (bit-banging) +and works on all pins:: from machine import Pin, SPI # construct an SPI 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 = SPI(-1, baudrate=100000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4)) spi.init(baudrate=200000) # set the baudrate @@ -189,6 +190,21 @@ The SPI driver is implemented in software and works on all pins:: spi.write_readinto(b'1234', buf) # write to MOSI and read from MISO into the buffer spi.write_readinto(buf, buf) # write buf to MOSI and read MISO back into buf + +Hardware SPI bus +---------------- + +The hardware SPI is faster (up to 80Mhz), but only works on following pins: +``MISO`` is GPIO12, ``MOSI`` is GPIO13, and ``SCK`` is GPIO14. It has the same +methods as the bitbanging SPI class above, except for the pin parameters for the +constructor and init (as those are fixed):: + + from machine import Pin, SPI + + hspi = SPI(1, baudrate=80000000, polarity=0, phase=0) + +(``SPI(0)`` is used for FlashROM and not available to users.) + I2C bus ------- @@ -239,15 +255,14 @@ The OneWire driver is implemented in software and works on all pins:: ow.scan() # return a list of devices on the bus ow.reset() # reset the bus ow.readbyte() # read a byte - ow.read(5) # read 5 bytes ow.writebyte(0x12) # write a byte on the bus ow.write('123') # write bytes on the bus ow.select_rom(b'12345678') # select a specific device by its ROM code -There is a specific driver for DS18B20 devices:: +There is a specific driver for DS18S20 and DS18B20 devices:: - import time - ds = onewire.DS18B20(ow) + import time, ds18x20 + ds = ds18x20.DS18X20(ow) roms = ds.scan() ds.convert_temp() time.sleep_ms(750) |