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Local Pi Display

Former Member

I have a model A Raspberry Pi and have been using it via a USB wireless adapter and Mint's Remote Desktop Protocol. 

 

I also have a Motorola Atrix docking station.  After I replaced my original cheap eBay HDMI cable with another cheap eBay HDMI cable, the Pi displays its boot messages and gets to the text log-in screen.  Unfortunately, the Pi doesn't see the Atrix keyboard/mouse so I can't log on.  I'm trying to fix this but because I am happy controlling the Pi remotely, I am more interested in using the Atrix display with RDP control.  So using the Atrix keyboard/touch pad isn't important.

 

Using RDP and the Pi terminal, I can get the Pi to display an X Desktop on its display by entering "sudo init 3".  While this is a step in the right direction now the Pi waits at a GUI log-in screen. 

 

I've tried multiple searches but it seems that any combination of "remote" "display" "local" "servel display" etc. just gives me results about using RDP (or SSH or VNC - all of which work for me).  I guess I'm not articulate enough to specify what I want.

 

Does any one know how to do this or at least can help me write a useful search question? 

 

One application is to use a Python program to monitor GPIO inputs and display them on the Pi.  A text display is acceptable but I prefer X Windows.

Parents

  • I've got several workstations that are "headless" in that they don't have a keyboard or mouse attached. But I AM using the display.

     

    What, at least by default, you don't want is that "random" guys on the network can tap into your session if you log in locally. So several steps are taken to prevent that from happening if you log into the local display/keyboard/mouse.

     

    First authentication is used: The login manager pulls a big random number out of a hat and tells the server: "Only allow programs that know THIS number to connect". When a succesful username/password is provided that user is logged in and the random number is copied over to HIS homedir, allowing programs under his uid to grab the number from the file and show the server that they know that number. I assume the number is changed once you log out.

     

    Secondly, some (most?) people seldomly use "remote display". A program running on one computer displaying on another. A very powerful and useful feature. But again: A program that can connect to the x-server would have too many powers. So it was decided that an X-server will start without the networking features enabled. (That's why I don't expect the "EXPORT DISPLAY=localhost:0.0" to work: it specifies to connect to the networking part of the protocol even though it stays local on the machine!).

     

    To prevent all that from interfering with what I want to do, I simply start the X server:
       X -ac :2

     

    The -ac means: Don't check authentications. And the :2 means: use the <hostname:2> as the display. This allows me to start it next to a running gui login program. On the other hand, that won't be necessary if you had to use "init 3" to get to the gui login. I then get to manually start everything I want. Personally I start:

    - xsetbg -solid steelblue (I've used that background since about 1990).

    - sawfish (A window manager that I've gotten used to).

    - gnome-panel (a panel that I've gotten used to).

     

    Of course I'm overriding several sensible security practises. But I trust and have-to-trust my local network. I have a firewall so that it is not connected to the internet etc. So I'm happy with this situation.

  • in reply to rew

    I appreciate the time peple have spent on my problem.  Obviously I have a lot to learn about Linux and X Windows.  Based on the responses, I think I need to pay more attention to the inherent security measures.  Since I am firewall protected and the only user on my network, I've ignored security.  Based on Roger's reply, I'll look into the necessity of actively defeating them.  I'll spend some time on his useful suggestions.

     

    Last night, I was able to remotely generate a window on the Pi's local LCD display using xterm.  Unfortunately, I was not able to write to it.  I'll keep banging away at it.

     

    It looks like I've done a poor job of explaining my desire so let me take one more shot at it.  I have a A model Pi with a USB wireless adapter.  The Pi has a local LCD display but no keyboard/mouse.  I would like to connect to the Pi remotely from a desktop, control the Pi and have the applications on the Pi be displayed in both the desktop's remote window and on the Pi's local LCD.  As I described in an earlier post, I think I have a method to do this but it requires temporary attachment of a keyboard to the Pi to initialize it. 

  • in reply to Former Member

    You should look at "xrdp".

     

    It will allow you to use a "remote mouse and keyboard" with your 'pi.

    My raspberry pi has "xrdp" in the repository. (so apt-get install xrdp will work!).

     

    I don't know right now if you'll have to run xrdp "from scratch" i.e. without starting the "X -ac" first, or if you'll have to run that first.

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  • in reply to Former Member

    You should look at "xrdp".

     

    It will allow you to use a "remote mouse and keyboard" with your 'pi.

    My raspberry pi has "xrdp" in the repository. (so apt-get install xrdp will work!).

     

    I don't know right now if you'll have to run xrdp "from scratch" i.e. without starting the "X -ac" first, or if you'll have to run that first.

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