circuitpython/docs/wipy/quickref.rst

.. _quickref_:

Quick reference for the WiPy
============================

.. image:: https://raw.githubusercontent.com/wipy/wipy/master/docs/PinOUT.png
    :alt: WiPy pinout and alternate functions table
    :width: 800px

General board control (including sleep modes)
---------------------------------------------

See the :mod:`machine` module::

    import machine

    help(machine) # display all members from the machine module
    machine.freq() # get the CPU frequency
    machine.unique_id() # return the 6-byte unique id of the board (the WiPy's MAC address)

    machine.idle()        # average current decreases to (~12mA), any interrupts wake it up
    machine.sleep()       # everything except for WLAN is powered down (~950uA avg. current)
                          # wakes from Pin, RTC or WLAN
    machine.deepsleep()   # deepest sleep mode, MCU starts from reset. Wakes from Pin and RTC.

Pins and GPIO
-------------

See :ref:`machine.Pin <machine.Pin>`. ::

    from machine import Pin

    # initialize GP2 in gpio mode (alt=0) and make it an output
    p_out = Pin('GP2', mode=Pin.OUT)
    p_out.value(1)
    p_out.value(0)
    p_out.toggle()
    p_out(True)

    # make GP1 an input with the pull-up enabled
    p_in = Pin('GP1', mode=Pin.IN, pull=Pin.PULL_UP)
    p_in() # get value, 0 or 1

Timers
------

See :ref:`machine.Timer <machine.Timer>` and :ref:`machine.Pin <machine.Pin>`. ::

    from machine import Timer
    from machine import Pin

    tim = Timer(1, mode=Timer.PERIODIC)
    tim_a = tim.channel(Timer.A, freq=1000)
    tim_a.time() # get the value in microseconds
    tim_a.freq(1) # 1 Hz
    
    p_out = Pin('GP2', mode=Pin.OUT)
    tim_a.irq(handler=lambda t: p_out.toggle())

PWM (pulse width modulation)
----------------------------

See :ref:`machine.Pin <machine.Pin>` and :ref:`machine.Timer <machine.Timer>`. ::

    from machine import Timer
    from machine import Pin

    # assign GP25 to alternate function 9 (PWM)
    p_out = Pin('GP25', mode=Pin.AF, alt=9)

    # timer 2 in PWM mode and width must be 16 buts
    tim = Timer(2, mode=Timer.PWM, width=16)
    
    # enable channel A @1KHz with a 50% duty cycle
    tim_a = tim.channel(Timer.A, freq=1000, duty_cycle=50)

ADC (analog to digital conversion)
----------------------------------

See :ref:`machine.ADC <machine.ADC>`. ::

    from machine import ADC

    adc = ADC()
    apin = adc.channel(pin='GP3')
    apin() # read value, 0-4095

UART (serial bus)
-----------------

See :ref:`machine.UART <machine.UART>`. ::

    from machine import UART
    uart = UART(0, baudrate=9600)
    uart.write('hello')
    uart.read(5) # read up to 5 bytes

SPI bus
-------

See :ref:`machine.SPI <machine.SPI>`. ::

    from machine import SPI

    # configure the SPI master @ 2MHz
    spi = SPI(0, SPI.MASTER, baudrate=200000, polarity=0, phase=0)
    spi.write('hello')
    spi.read(5) # receive 5 bytes on the bus
    rbuf = bytearray(5)
    spi.write_readinto('hello', rbuf) # send a receive 5 bytes

I2C bus
-------

See :ref:`machine.I2C <machine.I2C>`. ::

    from machine import I2C
    # configure the I2C bus
    i2c = I2C(0, I2C.MASTER, baudrate=100000)
    i2c.scan() # returns list of slave addresses
    i2c.writeto(0x42, 'hello') # send 5 bytes to slave with address 0x42
    i2c.readfrom(0x42, 5) # receive 5 bytes from slave
    i2c.readfrom_mem(0x42, 0x10, 2) # read 2 bytes from slave 0x42, slave memory 0x10
    i2c.writeto_mem(0x42, 0x10, 'xy') # write 2 bytes to slave 0x42, slave memory 0x10

Watchdog timer (WDT)
--------------------

See :ref:`machine.WDT <machine.WDT>`. ::

    from machine import WDT

    # enable the WDT with a timeout of 5s (1s is the minimum)
    wdt = WDT(timeout=5000)
    wdt.feed()

Real time clock (RTC)
---------------------

See :ref:`machine.RTC <machine.RTC>` ::

    import machine
    from machine import RTC

    rtc = machine.RTC() # init with default time and date
    rtc = RTC(datetime=(2015, 8, 29, 9, 0, 0, 0, None)) # init with a specific time and date
    print(rtc.now())

    def alarm_handler (rtc_o):
        pass
        # do some non blocking operations
        # warning printing on an irq via telnet is not
        # possible, only via UART 

    # create a RTC alarm that expires after 5 seconds
    rtc.alarm(time=5000, repeat=False)

    # enable RTC interrupts
    rtc_i = rtc.irq(trigger=RTC.ALARM0, handler=alarm_handler, wake=machine.SLEEP)

    # go into suspended mode waiting for the RTC alarm to expire and wake us up
    machine.sleep()

SD card
-------

See :ref:`machine.SD <machine.SD>`. ::

    from machine import SD
    import os

    # clock pin, cmd pin, data0 pin
    sd = SD(pins=('GP10', 'GP11', 'GP15'))
    # or use default ones for the expansion board
    sd = SD()
    os.mount(sd, '/sd')

WLAN (WiFi) 
-----------

See :ref:`network.WLAN <network.WLAN>` and :mod:`machine`. ::

    import machine
    from network import WLAN

    # configure the WLAN subsystem in station mode (the default is AP)
    wlan = WLAN(mode=WLAN.STA)
    # go for fixed IP settings
    wlan.ifconfig(config=('192.168.0.107', '255.255.255.0', '192.168.0.1', '8.8.8.8'))
    wlan.scan()     # scan for available networks
    wlan.connect(ssid='mynetwork', auth=(WLAN.WPA2, 'mynetworkkey'))
    while not wlan.isconnected():
        pass
    print(wlan.ifconfig())
    # enable wake on WLAN
    wlan.irq(trigger=WLAN.ANY_EVENT, wake=machine.SLEEP)
    # go to sleep
    machine.sleep()
    # now, connect to the FTP or the Telnet server and the WiPy will wake-up

Telnet and FTP server
---------------------

See :ref:`network.server <network.server>` ::

    from network import server

    # init with new user, password and seconds timeout
    server = server.init(login=('user', 'password'), timeout=60)
    server.timeout(300) # change the timeout
    server.timeout() # get the timeout
    server.isrunning() # check wether the server is running or not

Heart beat LED
--------------

See :mod:`wipy`. ::

    import wipy

    wipy.heartbeat(False)  # disable the heartbeat LED
    wipy.heartbeat(True)   # enable the heartbeat LED
    wipy.heartbeat()       # get the heartbeat state