111 lines
4.3 KiB
ReStructuredText
111 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 pyboard. 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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To use the REPL, you must connect to the serial USB device on the pyboard.
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How you do this depends on your operating system.
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Windows
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-------
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You need to install the pyboard driver to use the serial USB device.
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The driver is on the pyboard's USB flash drive, and is called ``pybcdc.inf``.
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To install this driver you need to go to Device Manager
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for your computer, find the pyboard in the list of devices (it should have
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a warning sign next to it because it's not working yet), right click on
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the pyboard device, select Properties, then Install Driver. You need to
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then select the option to find the driver manually (don't use Windows auto update),
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navigate to the pyboard's USB drive, and select that. It should then install.
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After installing, go back to the Device Manager to find the installed pyboard,
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and see which COM port it is (eg COM4).
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More comprehensive instructions can be found in the
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`Guide for pyboard on Windows (PDF) <http://micropython.org/resources/Micro-Python-Windows-setup.pdf>`_.
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Please consult this guide if you are having problems installing the driver.
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You now need to run your terminal program. You can use HyperTerminal if you
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have it installed, or download the free program PuTTY:
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`putty.exe <http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html>`_.
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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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screen /dev/tty.usbmodem*
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When you are finished and want to exit screen, type CTRL-A CTRL-\\.
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Linux
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-----
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Open a terminal and run::
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screen /dev/ttyACM0
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You can also try ``picocom`` or ``minicom`` instead of screen. You may have to
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use ``/dev/ttyACM1`` or a higher number for ``ttyACM``. 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 pyboard.
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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 pyboard!")
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hello pyboard!
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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 pyboard!")`` 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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>>> pyb.LED(1).on()
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>>> pyb.LED(2).on()
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>>> 1 + 2
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3
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>>> 1 / 2
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0.5
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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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MPY: sync filesystems
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MPY: soft reboot
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Micro Python v1.0 on 2014-05-03; PYBv1.0 with STM32F405RG
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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 RST
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switch (the small black button closest to the micro-USB socket on the board). This will end your
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session, disconnecting whatever program (PuTTY, screen, etc) that you used to connect to the pyboard.
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If you are going to do a hard-reset, it's recommended to first close your serial program and eject/unmount
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the pyboard drive.
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