131 lines
4.3 KiB
ReStructuredText
131 lines
4.3 KiB
ReStructuredText
Getting a MicroPython REPL prompt
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=================================
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REPL stands for Read Evaluate Print Loop, and is the name given to the
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interactive MicroPython prompt that you can access on the WiPy. Using
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the REPL is by far the easiest way to test out your code and run commands.
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You can use the REPL in addition to writing scripts in ``main.py``.
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.. _wipy_uart:
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To use the REPL, you must connect to the WiPy either via :ref:`telnet <wipy_telnet>`,
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or with a USB to serial converter wired to one of the two UARTs on the
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WiPy. To enable REPL duplication on UART0 (the one accessible via the expansion board)
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do::
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>>> from machine import UART
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>>> import os
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>>> uart = UART(0, 115200)
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>>> os.dupterm(uart)
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Place this piece of code inside your ``boot.py`` so that it's done automatically after
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reset.
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Windows
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-------
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First you need to install the FTDI drivers for the expansion board's USB to serial
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converter. Then you need a terminal software. The best option is to download the
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free program PuTTY: `putty.exe <http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html>`_.
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**In order to get to the telnet REPL:**
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Using putty, select ``Telnet`` as connection type, leave the default port (23)
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and enter the IP address of your WiPy (192.168.1.1 when in ``WLAN.AP`` mode),
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then click open.
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**In order to get to the REPL UART:**
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Using your serial program you must connect to the COM port that you found in the
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previous step. With PuTTY, click on "Session" in the left-hand panel, then click
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the "Serial" radio button on the right, then enter you COM port (eg COM4) in the
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"Serial Line" box. Finally, click the "Open" button.
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Mac OS X
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--------
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Open a terminal and run::
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$ telnet 192.168.1.1
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or::
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$ screen /dev/tty.usbmodem* 115200
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When you are finished and want to exit ``screen``, type CTRL-A CTRL-\\. If your keyboard does not have a \\-key (i.e. you need an obscure combination for \\ like ALT-SHIFT-7) you can remap the ``quit`` command:
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- create ``~/.screenrc``
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- add ``bind q quit``
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This will allow you to quit ``screen`` by hitting CTRL-A Q.
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Linux
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-----
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Open a terminal and run::
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$ telnet 192.168.1.1
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or::
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$ screen /dev/ttyUSB0 115200
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You can also try ``picocom`` or ``minicom`` instead of screen. You may have to
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use ``/dev/ttyUSB01`` or a higher number for ``ttyUSB``. And, you may need to give
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yourself the correct permissions to access this devices (eg group ``uucp`` or ``dialout``,
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or use sudo).
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Using the REPL prompt
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---------------------
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Now let's try running some MicroPython code directly on the WiPy.
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With your serial program open (PuTTY, screen, picocom, etc) you may see a blank
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screen with a flashing cursor. Press Enter and you should be presented with a
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MicroPython prompt, i.e. ``>>>``. Let's make sure it is working with the obligatory test::
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>>> print("hello WiPy!")
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hello WiPy!
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In the above, you should not type in the ``>>>`` characters. They are there to
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indicate that you should type the text after it at the prompt. In the end, once
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you have entered the text ``print("hello WiPy!")`` and pressed Enter, the output
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on your screen should look like it does above.
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If you already know some Python you can now try some basic commands here.
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If any of this is not working you can try either a hard reset or a soft reset;
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see below.
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Go ahead and try typing in some other commands. For example::
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>>> from machine import Pin
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>>> import wipy
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>>> wipy.heartbeat(False) # disable the heartbeat
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>>> led = Pin('GP25', mode=Pin.OUT)
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>>> led(1)
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>>> led(0)
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>>> led.toggle()
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>>> 1 + 2
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3
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>>> 4 // 2
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2
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>>> 20 * 'py'
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'pypypypypypypypypypypypypypypypypypypypy'
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Resetting the board
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-------------------
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If something goes wrong, you can reset the board in two ways. The first is to press CTRL-D
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at the MicroPython prompt, which performs a soft reset. You will see a message something like::
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>>>
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PYB: soft reboot
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MicroPython v1.4.6-146-g1d8b5e5 on 2015-10-21; WiPy with CC3200
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Type "help()" for more information.
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>>>
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If that isn't working you can perform a hard reset (turn-it-off-and-on-again) by pressing the
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RST switch (the small black button next to the heartbeat LED). During telnet, this will end
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your session, disconnecting whatever program that you used to connect to the WiPy.
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