I can't login in to Octopi after installing lightdm


#1

Hi I'm looking for some help, I'm new-ish to the Rasp Pi and I can't understand what i'm doing wrong. I have 3 Rasp pi's and I'm still getting the same problem with all of them so I know it is not the hardware. I can get octopi running and can login with the usual method. I can even use putty and login from any other PC in my house with no problem. But as soon as I put a 5" HDMI touch screen onto the pi and run :-

" sudo apt-get install lightdm " it all goes wrong even when I plug the HDMI into a monitor. I can use putty to login but when I set the Raspi in the config menu to boot straight to GUI / desktop I can't log in. I keep going around in circles, with it not accepting my login or password.

I've pressed ctrl+alt+F1 and changed the password and I still can't login.

I've done :-

sudo rpi-update
sudo reboot

then after that did

sudo apt-get update
sudo apt-get upgrade

and still I can't login to the octopi GUI / desktop.

I know there is nothing wrong with the 5" touch screen I've had other programs running on it.

Can anybody please point me in the right direction or can someone post a copy of a working Octopi image that works with lightdm and boots straight to the desktop.

Many thanks
Paul


#2

Wow. Where to begin? I guess I'll go with the voices of the little men who live behind my eyes and shout instructions to me (in order of their volume):

  • sudo rpi-update is awesome if you are actively developing low-level hardware drivers for Raspbian. It is normally used so that one may update the Raspbian firmware to the bleeding-edge next branch rather than the what would be considered a safe, long-term support master branch. Depending upon your timing, this is a great way to brick your Raspberry Pi. I have often argued online with people who suggest that this is the tool to use and that "it always works for me". The official Raspberry Pi page in no way suggests this path.
  • The sudo apt-get update && sudo apt-get -y upgrade path would normally be suggested but it could potentially break the OctoPi image in some cases. (Your mileage may vary.)
  • I've found that Adafruit's install script often does the least amount of harm for me when installing touchscreens.
  • OctoPi's ~/scripts/install-desktop script is the preferred method of first adding the X windows and Desktop interface to the standard Raspbian Stretch Lite starting point. sudo /home/pi/scripts/install-desktop This is functionally the equivalent of sudo apt-get install lightdm but is the expected upgrade path for an OctoPi install.
  • You might want to use a standard HDMI screen first with a keyboard/mouse and the vanilla OctoPi image. Get that configured for your network. Next, run the install-desktop script. Next, install the touchscreen and see if it boots locally. If so, install the drivers for your touchscreen, preferably using Adafruit's script. (You might not actually need to, though.)

You'd need to identify which of their products you ended up with.

There's a difference between getting the display to work as expected and to get the touchscreen to work as an input device (and all in the correct orientation). The Adafruit's instructions seem to the be best of those available, in my humble opinion.