Editing PyMaemo/Quick start guide

Warning: You are not logged in. Your IP address will be recorded in this page's edit history.
The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision Your text
Line 1: Line 1:
-
= Getting Started: Setting Up Python Development Environment for N900 =
+
= Running Python code on N900 (quick start guide) =
-
A basic development environment for Python development for Maemo consists of:
+
This article will describe the necessary steps to get your Python application running on N900. For the instructions to work, you need to have Internet connectivity on your device (e.g. WLAN or GPRS).
-
* A source code editor
+
== Installing OpenSSH ==
-
* Some way to transfer application files to the tablet
+
-
* Easily run the application (without installing it)
+
-
 
+
-
Alternatively, you can try other more complex development environments, briefly described at the end of this article.
+
-
 
+
-
This article will cover:
+
-
 
+
-
* Installation of necessary packages and USB connectivity setup
+
-
* Some suggestions for Python code editors
+
-
* How to transfer the application files to the N900
+
-
* How to run the application
+
-
 
+
-
Application packaging and final deployment will be discussed separately at a later date.
+
-
 
+
-
Finally, there is a [http://www.youtube.com/watch?v=onAkb_7U5pk screencast] demonstrating the instructions from this guide, which should help clarifying some of the steps in a real setup session.
+
-
 
+
-
== Requirements ==
+
-
 
+
-
Before continuing, make sure you have:
+
-
 
+
-
Tablet requirements:
+
-
 
+
-
* Some kind of connectivity to the tablet (e.g. WLAN or GPRS), so that you can install required packages.
+
-
* The N900 USB cable, which will be used to transfer files to the tablet.
+
-
 
+
-
Host requirements:
+
-
 
+
-
* An SSH client. For Linux, OpenSSH (through the "ssh" command) is enough. For Windows, [http://en.sourceforge.jp/projects/ttssh2/releases/ Tera Term] can be used. For Mac you can use "ssh" command in the Terminal.
+
-
* An SCP/SFTP client. For Linux, OpenSSH (through the "scp" command) is enough. The KDE/GNOME environments also have built-in support for these protocols. For Windows, you can try [http://winscp.net/eng/index.php WinSCP] or [http://filezilla-project.org/ FileZilla].
+
-
 
+
-
For the purposes of this tutorial, you will '''not''' need Scratchbox installed. Scratchbox would only be necessary if you are unable to test your applications on the actual tablet.
+
-
 
+
-
== Installing required packages on N900 ==
+
-
 
+
-
You will need to install two applications on the tablet:
+
-
 
+
-
* [http://maemo.org/packages/view/openssh-server/ OpenSSH Server]
+
-
* [http://maemo.org/packages/view/rootsh/ rootsh]
+
-
 
+
-
rootsh appears to have been replaced by either running <code>sudo gainroot</code> directly, or by running <code>root</code>.
+
OpenSSH is needed to run commands remotely on your N900. This will make testing on the device a lot easier.
OpenSSH is needed to run commands remotely on your N900. This will make testing on the device a lot easier.
-
[[Root access]] is needed to allow to run commands as root on the X Terminal (using <code>sudo gainroot</code>).
+
If you are able to access the Internet from your N900 (e.g. using WLAN or GPRS) follow these instructions:
-
To install these applications, follow these steps:
+
# Enable extras repository. See http://wiki.maemo.org/Extras#Using_Extras for how to do it.
-
 
+
# Install the package named "OpenSSH Client and Server". The client is also needed so we can enable USB networking in the next session, by ssh'ing to root@localhost. Optionally, you can install the rootsh package to enable local root access. See http://wiki.maemo.org/Root_access for details.
-
# [[Extras#Using Extras|Enable the extras repository]].
+
# The installation will ask for a new root password. Choose a good one.
-
# Install the packages listed above.
+
-
# The installation will ask for a new root password for SSH access. Choose a good one.
+
# Wait for installation to complete.
# Wait for installation to complete.
== Enabling USB networking ==
== Enabling USB networking ==
-
USB networking allows to easily and quickly transfer files to the device and connect to it using SSH.
+
USB networking allows fast remote access to the device. To enable it, follow these steps (you need to repeat them every time you reboot the device:
-
Note that this is not the only way to transfer files to the device. If you are already setup with your N900 and your desktop on the same LAN over Wifi, you can save yourself the trouble and skip this USB networking configuration section.
+
# If the USB cable is plugged and in "Mass storage mode", unpplug the cable and plug it again, now selecting "PC Suite Mode".
 +
# On N900, open "X Terminal" and run:
 +
ssh root@localhost ifup usb0
-
To enable USB networking, follow these steps (you need to repeat them every time you reboot the device):
+
This command will ask for SSH fingerprint confirmation (because it is the first connection), and after typing the root password, USB networking will be enabled.
-
# If the USB cable is plugged and in "Mass storage mode", unplug the cable and plug it again, now selecting "PC Suite Mode".
+
Now configure the host. This is dependent on which OS (or Linux distro) you use, see http://wiki.maemo.org/USB_networking#Host_USB_Network_Configuration for detailed instructions for vaious OSes and Linux distros.
-
# On N900, open "X Terminal" and run:
+
-
rootsh ifup usb0
+
-
# Now you need to configure the host. This is dependent on which OS (or Linux distro) you use, but there are [[USB networking#Host USB Network Configuration|detailed instructions for various OSes and Linux distros]].
+
-
From now on you can connect to the N900 using any SSH client and the following information:
+
From now on you can connect to the N900 from your PC by using:
-
Host: 192.168.2.15
+
-
Port: 22
+
-
User: root
+
-
Password: the password setup earlier
+
-
 
+
-
For instance, from a Linux terminal, you can connect to the tablet using this command:
+
  ssh root@192.168.2.15
  ssh root@192.168.2.15
Line 81: Line 32:
== Preparing the N900 for Python Development ==
== Preparing the N900 for Python Development ==
-
To enable the full power for Python development for Maemo, you must enable the "extras-devel" repository on your device. ''Be advised that this might be a risky operation'' because extras-devel contains many untested and possibly broken packages. But it also contains the latest versions of all available Python bindings for Maemo, which we are interested on.
+
To enable the full power for Python development for Maemo, you must enable the "extras-devel" repository on your device. Note that this might be a risky operation because extras-devel contains many untested and possibly broken packages. But it also contains the latest versions of all available Python bindings for Maemo, which we are interested on.
 +
 
 +
To enable extras-devel add a new catalogue to the Application Manager, as instructed in https://wiki.maemo.org/Extras-devel (did you see the big warning on that page?)
 +
 
 +
Next, you need to install the packages you use (or plan to) on your application by running (through SSH):
-
Note that the requirement to enable the "extras-devel" repository might be removed later.
+
apt-get update && apt-get install <packages>
-
To enable extras-devel add a new catalogue to the Application Manager, as instructed in [[Extras-devel]] (did you see the big warning on that page?)
+
Where <packages> are the list of packages you are going to use. For instance, for a general GUI application, you will probably need at least "python-gtk2" and "python-hildon". See http://wiki.maemo.org/PyMaemo/Components for the current list of available packages.
-
After extras-devel is enabled, you will see on Application Manager a package called "maemo-python-device-env". Installing it will also install the basic environment necessary to run most Python applications on Maemo.
+
== Running the Python application on the device (finally!) ==
-
== Writing your code ==
+
Now that you have the N900 properly setup, you just need to copy the Python code to the device and run it.
-
Any good programmer oriented editor will be enough for development. If you have some development experience, you most probably already have chosen your favorite code editor and you can simply use it.
+
=== Single file applications ===
-
Here we list some options, both for Linux and Windows:
+
If your application consists of a single .py file, you can just copy it to the device using:
-
* [http://projects.gnome.org/gedit/ gedit]: the GNOME Editor has syntax highlight support for Python
+
scp my_script.py root@192.168.2.15:/root
-
* [http://www.vim.org/ VIM] and [http://www.gnu.org/software/emacs/ Emacs]: the most popular editors, with many advanced features and versions for both Linux and Windows
+
-
* [http://wiki.netbeans.org/Python NetBeans + Python plugin]: NetBeans is a multi-platform IDE, which with help of a plugin, supports development for Python
+
-
* [http://maemo.org/downloads/product/Maemo5/pygtkeditor/ PyGTKEditor]: a syntax highlighting Python editor which runs natively on Maemo devices
+
-
Note that none of these editors will support code completion for PyMaemo modules out of box.
+
And to run the application on N900:
-
For testing purposes, you can try the following code (the classic "hello world" example):
+
ssh root@192.168.2.15 run-standalone.sh python2.5 /root/my_script.py
-
import gtk
+
The application should then open on the device's screen, and any errors will be print on the terminal where you run the command below.
-
from gtk import Window, Button, Widget
+
-
if __name__ == "__main__":
+
-
    window = Window(gtk.WINDOW_TOPLEVEL)
+
-
    window.connect("destroy", gtk.main_quit)
+
-
    button = Button("Hello World")
+
-
    button.connect_object("clicked", Widget.destroy, window)
+
-
    window.add(button)
+
-
    window.show_all()
+
-
    gtk.main()
+
-
Once you have your code written, you can proceed to copying application files to the device.
+
Alternatively, you can use this single command to run the code "on the fly" (i.e. without copying anything to the device):
-
== Running the Python application on the device ==
+
cat my_script.py | ssh root@192.168.2.15 run-standalone.sh python2.5
-
Now that you have the N900 properly setup and the code to run, you just need to copy the application files to the device and run it.
+
===Multiple file applications ===
-
The simplest way to copy files it to use a SFTP or SCP client. There are many free clients available for most OSes (we listed some examples on the "Requirements" section). On the Linux command line, you can use:
+
For applications which contain more than one file (e.g. images, or other Python files), you need to make all the necessary files accessible on the device. The simplest way is to copy all the code to some directory on the device, which you could do by using this single line:
-
  scp -pr my_application/ root@192.168.2.15:/root/my_application/
+
  tar -cf- my_application_dir/ | ssh root@192.168.2.15 tar -C /root -xvf-
-
Replace "my_application/" with the path to the directory which contains your application files.
+
This command uses a combination of tar and ssh to copy all files under a directory recursively (taking care to keep permissions intact). Then, to run the application, use a command like this:
-
Finally, to run the application on the tablet, use (from a SSH terminal):
+
ssh root@192.168.2.15 run-standalone.sh python2.5 /root/my_application_dir/my_script.py
-
cd /root/my_application
+
Alternatively, you can install the "sshfs" package on your PC (it is available at least on Debian and Ubuntu systems), and run:
-
python my_application.py
+
-
== Alternative development environments ==
+
sshfs root@192.168.2.15:/root some_local_dir
-
Besides the environment described on this article, there are two alternative development environments that might or might not be more appropriate for your purposes:
+
This will make the N900's /root directory accessible on some_local_dir directory on the PC. You can copy files to some_local_dir and they will be transparently copied to the device. To run the application, use the same command as shown earlier.
-
; PluThon (Eclipse based)
+
Once you don't need to access the directory anymore, run:
-
: [http://pluthon.garage.maemo.org/ PluThon] is a full Python IDE for Maemo, based on Eclipse. While PluThon is easy to use and provides a complete solution, it is not necessary for basic Python development for Maemo. If you already use Eclipse for your development, PluThon might be your best option.
+
-
; Official Maemo SDK (Scratchbox based)
+
-
: [http://www.scratchbox.org/ Scratchbox] is a cross-compilation toolkit used for native Maemo development. Although it can be used in Python development as well (and comes very handy if you do not have access to a real device), it has a non-trivial learning curve and is not needed for pure Python development. However, if you plan to write new Python extensions (for instance, using [http://www.cython.org/ Cython] or [http://docs.python.org/c-api/index.html Python/C API] directly), Scratchbox is needed to cross-compile the C code. See the [http://wiki.maemo.org/Documentation/Maemo_5_Developer_Guide/Development_Environment/Maemo_SDK Maemo SDK section] on Maemo 5 developer guide for more details on it.
+
-
Note that PluThon has built-in support for transferring and running code on the device. On the other hand, the Maemo SDK has no such support (unless you use some IDE like [http://esbox.garage.maemo.org/ ESbox]), so you need to follow steps similar to the ones described on this guide to copy and run your code on the tablet, if you choose to use the Maemo SDK.
+
umount some_local_dir
-
== Advanced tips ==
+
sshfs can also be used the other way around: you can access your application's directory directly from the N900 (so no copying is needed at all). For that, install the "sshfs" package on N900 by running:
-
If you want to activate USB networking automatically upon connecting the device to the computer, just create a file called /etc/event.d/usbnet on the device with the following contents:
+
apt-get install sshfs
-
start on G_NOKIA_READY
+
Make sure you have OpenSSH server installed on your PC, and run:
-
+
-
console output
+
-
exec ifconfig usb0 192.168.2.15 netmask 255.255.255.0 up
+
-
This way you just have to select "PC Suite mode" when plugging the device in.
+
ssh root@192.168.2.15 # this will log into the N900
 +
mkdir /root/host_fs
 +
sshfs <USER>@192.168.2.14:/path/to/my_application_dir /root/host_fs
 +
run-standalone.sh python2.5 /root/host_fs/my_script.py
-
[[Category:N900]]
+
Once you don't need to access the directory anymore, run:
-
[[Category:Python]]
+
ssh root@192.168.2.15 umount /root/host_fs

Learn more about Contributing to the wiki.


Please note that all contributions to maemo.org wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see maemo.org wiki:Copyrights for details). Do not submit copyrighted work without permission!


Cancel | Editing help (opens in new window)
Retrieved from "http://wiki.maemo.org/PyMaemo/Quick_start_guide"