docs/rp2: Enhance quickref and change image to Pico pinout.
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NitiKaur
Damien George
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@ -3,7 +3,7 @@
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Quick reference for the RP2
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===========================
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.. image:: img/rpipico.jpg
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.. image:: img/pico_pinout.png
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:alt: Raspberry Pi Pico
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:width: 640px
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@ -27,10 +27,9 @@ a troubleshooting subsection.
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General board control
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---------------------
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The MicroPython REPL is on the USB serial port.
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Tab-completion is useful to find out what methods an object has.
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Paste mode (ctrl-E) is useful to paste a large slab of Python code into
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the REPL.
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The MicroPython REPL is accessed via the USB serial port. Tab-completion is useful to
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find out what methods an object has. Paste mode (ctrl-E) is useful to paste a
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large slab of Python code into the REPL.
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The :mod:`machine` module::
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@ -59,7 +58,19 @@ Use the :mod:`time <utime>` module::
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Timers
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------
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How do they work?
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RP2040's system timer peripheral provides a global microsecond timebase and
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generates interrupts for it. The software timer is available currently,
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and there are unlimited number of them (memory permitting). There is no need
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to specify the timer id (id=-1 is supported at the moment) as it will default
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to this.
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Use the :mod:`machine.Timer` class::
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from machine import Timer
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tim = Timer(period=5000, mode=Timer.ONE_SHOT, callback=lambda t:print(1))
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tim.init(period=2000, mode=Timer.PERIODIC, callback=lambda t:print(2))
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.. _rp2_Pins_and_GPIO:
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@ -84,19 +95,28 @@ Use the :ref:`machine.Pin <machine.Pin>` class::
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UART (serial bus)
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-----------------
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There are two UARTs, UART0 and UART1. UART0 can be mapped to GPIO 0/1, 12/13
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and 16/17, and UART1 to GPIO 4/5 and 8/9.
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See :ref:`machine.UART <machine.UART>`. ::
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from machine import UART
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uart1 = UART(1, baudrate=9600, tx=33, rx=32)
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from machine import UART, Pin
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uart1 = UART(1, baudrate=9600, tx=Pin(4), rx=Pin(5))
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uart1.write('hello') # write 5 bytes
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uart1.read(5) # read up to 5 bytes
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.. note::
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REPL over UART is disabled by default. You can see the :ref:`rp2_intro` for
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details on how to enable REPL over UART.
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PWM (pulse width modulation)
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----------------------------
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How does PWM work on the RPi RP2xxx?
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There are 8 independent channels each of which have 2 outputs making it 16
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PWM channels in total which can be clocked from 7Hz to 125Mhz.
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Use the ``machine.PWM`` class::
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@ -112,14 +132,18 @@ Use the ``machine.PWM`` class::
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ADC (analog to digital conversion)
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----------------------------------
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How does the ADC module work?
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RP2040 has five ADC channels in total, four of which are 12-bit SAR based
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ADCs: GP26, GP27, GP28 and GP29. The input signal for ADC0, ADC1, ADC2 and
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ADC3 can be connected with GP26, GP27, GP28, GP29 respectively (On Pico board,
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GP29 is connected to VSYS). The standard ADC range is 0-3.3V. The fifth
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channel is connected to the in-built temperature sensor and can be used for
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measuring the temperature.
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Use the :ref:`machine.ADC <machine.ADC>` class::
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from machine import ADC
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adc = ADC(Pin(32)) # create ADC object on ADC pin
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adc.read_u16() # read value, 0-65535 across voltage range 0.0v - 3.3v
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from machine import ADC, Pin
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adc = ADC(Pin(26)) # create ADC object on ADC pin
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adc.read_u16() # read value, 0-65535 across voltage range 0.0v - 3.3v
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Software SPI bus
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----------------
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@ -132,7 +156,7 @@ Software SPI (using bit-banging) works on all pins, and is accessed via the
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# construct a SoftSPI bus on the given pins
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# polarity is the idle state of SCK
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# phase=0 means sample on the first edge of SCK, phase=1 means the second
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spi = SoftSPI(baudrate=100000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4))
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spi = SoftSPI(baudrate=100_000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4))
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spi.init(baudrate=200000) # set the baudrate
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@ -156,14 +180,15 @@ Software SPI (using bit-banging) works on all pins, and is accessed via the
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Hardware SPI bus
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----------------
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Hardware SPI is accessed via the :ref:`machine.SPI <machine.SPI>` class and
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has the same methods as software SPI above::
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The RP2040 has 2 hardware SPI buses which is accessed via the
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:ref:`machine.SPI <machine.SPI>` class and has the same methods as software
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SPI above::
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from machine import Pin, SPI
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spi = SPI(1, 10000000)
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spi = SPI(1, 10000000, sck=Pin(14), mosi=Pin(13), miso=Pin(12))
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spi = SPI(2, baudrate=80000000, polarity=0, phase=0, bits=8, firstbit=0, sck=Pin(18), mosi=Pin(23), miso=Pin(19))
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spi = SPI(1, 10_000_000) # Default assignment: sck=Pin(10), mosi=Pin(11), miso=Pin(8)
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spi = SPI(1, 10_000_000, sck=Pin(14), mosi=Pin(15), miso=Pin(12))
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spi = SPI(0, baudrate=80_000_000, polarity=0, phase=0, bits=8, sck=Pin(6), mosi=Pin(7), miso=Pin(4))
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Software I2C bus
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----------------
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@ -173,7 +198,7 @@ accessed via the :ref:`machine.SoftI2C <machine.SoftI2C>` class::
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from machine import Pin, SoftI2C
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i2c = SoftI2C(scl=Pin(5), sda=Pin(4), freq=100000)
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i2c = SoftI2C(scl=Pin(5), sda=Pin(4), freq=100_000)
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i2c.scan() # scan for devices
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@ -191,8 +216,8 @@ has the same methods as software I2C above::
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from machine import Pin, I2C
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i2c = I2C(0)
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i2c = I2C(1, scl=Pin(5), sda=Pin(4), freq=400000)
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i2c = I2C(0) # default assignment: scl=Pin(9), sda=Pin(8)
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i2c = I2C(1, scl=Pin(3), sda=Pin(2), freq=400_000)
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Real time clock (RTC)
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---------------------
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@ -202,13 +227,15 @@ See :ref:`machine.RTC <machine.RTC>` ::
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from machine import RTC
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rtc = RTC()
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rtc.datetime((2017, 8, 23, 2, 12, 48, 0, 0)) # set a specific date and time
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rtc.datetime((2017, 8, 23, 2, 12, 48, 0, 0)) # set a specific date and
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# time, eg. 2017/8/23 1:12:48
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rtc.datetime() # get date and time
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WDT (Watchdog timer)
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--------------------
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Is there a watchdog timer?
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The RP2040 has a watchdog which is a countdown timer that can restart
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parts of the chip if it reaches zero.
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See :ref:`machine.WDT <machine.WDT>`. ::
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@ -218,21 +245,6 @@ See :ref:`machine.WDT <machine.WDT>`. ::
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wdt = WDT(timeout=5000)
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wdt.feed()
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Deep-sleep mode
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---------------
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Is there deep-sleep support for the rp2?
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The following code can be used to sleep, wake and check the reset cause::
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import machine
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# check if the device woke from a deep sleep
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if machine.reset_cause() == machine.DEEPSLEEP_RESET:
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print('woke from a deep sleep')
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# put the device to sleep for 10 seconds
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machine.deepsleep(10000)
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OneWire driver
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--------------
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