MagicMirror screen goes black

[stuartiannaylor]

https://github.com/MichMich/MMM-WatchDog

Isn’t this supposed to cover such occasions as that and restart the server.
I only have a Pi-Zero so far so have never tested the effect with the normal Electron setup just Chromium standalone kiosk style.
So I don’t actually no if or what the mechanism to restart the browser (Electron) is.
If it doesn’t refresh via MMM-WatchDog you can always use xdotools to send keys to an Xwindow and all you need to do is a ‘ctrl+F5’ which is a refresh and drops the cache so all is effectively loaded as new.

sudo apt-get install xdotool 

Then with ~/MagicMirror/run-start.sh add a line and nano xdotool.sh and chmod a+x xdotool.sh

if [ -z "$DISPLAY" ]; then #If not set DISPLAY is SSH remote or tty
	export DISPLAY=:0 # Set by default display
fi
sh xdotool.sh &
electron js/electron.js $1

With xdotool.sh being something like this

export DISPLAY=:0
export XAUTHORITY=~/.Xauthority
sleep 10
xdotool search --onlyvisible --class "chromium" key ctrl+F5  -v 2>&1 | logger &

Dunno what the Electron class is but really its just Chromium in a wrapper so expecting that actually that will work.
If not you will just have to do a bit of testing to find the class or PID of electron http://manpages.ubuntu.com/manpages/trusty/man1/xdotool.1.html

[stuartiannaylor]

Replied again cursed by that akismi bot troll thing.

PS still setting it up but just monitor your logs.

Create a shell script with something like

 tail -fn0 logfile | \
while read line ; do
        echo "$line" | grep "pattern"
        if [ $? = 0 ]
        then
                ... do something ...
        fi
done

Maybe with a --retry to the tail command, or use -F instead of -f

Tack it onto your electron log and do the above xdotool.

[stuartiannaylor]

I gave you some bum steers on export XAUTHORITY=~/.Xauthority but prob was when I was using lightdm but for it to work omit that line.

I have 2 monitors running well 1 really as the Chromium one isn’t really doing anything as all is working fine.

xdotool.sh ended up just being

if [ -z "$DISPLAY" ]; then #If not set DISPLAY is SSH remote or tty
	export DISPLAY=:0 # Set by default display
fi
xdotool search --onlyvisible --class "chromium" key ctrl+F5  -v 2>&1 | logger &

chrome-log.sh is just

#Grep is a bit confusing as \| ie OR not AND so you get the following of Or + inline there is the other string
#grep -q '8080\|ERROR' would return true if either exist (OR)
( tail -f -n0 ~/.config/chromium/chrome_debug.log & ) | grep -q '8080.*ERROR\|ERROR.*8080'
sh xdotool.sh

Main one for me is the PM2 one that waits for MagicMirror to say all is finished and point your browser

( tail -f -n0 ~/.pm2/logs/MagicMirror-out.log & ) | grep -q 'Ready to go! Please point your browser to:'
sh xdotool.sh

Better explanation can be found on https://github.com/StuartIanNaylor/MagicMirror-Install-Guide-Raspberry-0-to-3/tree/master/Magic Monitor

[motdog]

i have a black screen too. Just got dark sky working. was finally happy and while rebooting after installing another module it goes to black. I thought it was my pi (3b) so I tried my other pi 3b+ and just black. I noticed earlier what looked like a draining battery icon but have no clue what that could mean. I do have a cursor on my black screen. alt tab shows Electon but I cant do anything from there. Help

[sdetweil]

@motdog run

npm start dev

Select the console tab, and scroll back to find any errors, red text.

Usually black screen is syntax error in module.js

[motdog]

@sdetweil I can’t get to terminal. All I have is black screen with pointer on it. I’m sure it was when I copied a config

[sdetweil]

@motdog ctrl-shift-i

[motdog]

Thanks I’ll try in the morning. If I can somehow get to config.js I’ll undo what I did. Appreciate all of your help!

[sdetweil]

@motdog always make sure u have an alternative way into the system. Like ssh from your PC.

[motdog]

@sdetweil I use VNC viewer pretty much all of the time to access this and nothing happens. I do see the green light occasionally flash on the pi when I try with the keyboard hooked up to it & my tv.