My printer is "offline"

 

Lost internet connection

The most common reason why the printer goes offline is that your raspberry pi is no longer connected to the Internet. An unstable internet connection may cause the raspberry to jump off and have difficulty connecting again. Restarting it works once in a while but the best thing you can do is move the raspberry closer to your wifi router to improve signal strength. Also make sure that your raspberry is not covered up too much, especially not by metal as the raspberry's antenna gets blocked and degrades the signal between your router and raspberry pi.

Many newer routers have 2 frequencies it puts out, a 2.4, and a 5 GigaHertz signal. They are typically combined into one connection and the router itself ensures that the devices that are connected are set up at the correct frequency. If you use the slightly older raspberry pi 3b (not the plus version), it does not have the ability to connect to the 5 GHz signal and it is therefore important that your 2.4 GHz connection is also running. You can test if you have a 2.4 GHz connection by finding the properties of your wifi on a computer or phone.

Windows

On a Windows machine, you can click on the wifi icon in the bottom right corner and then click on "Properties" on the connection you are on. The settings will open and you can scroll all the way to the bottom where you will find "Network band" If it says 2.4 GHz you can be sure that your 2.4 GHz connection works.

Android

On an Android phone, you can get into the wifi settings and click on the gear next to your wifi connection and there should be "Frequency" in the list below. If it says 2.4 GHz, you can be sure that your 2.4 GHz connection works.

OctoPrint has gone down

It may happen that OctoPrint that is running on your Raspberry Pi has stopped and therefore can not communicate with SimplyPrint anymore. You can check this by going to the IP address of your Raspberry and see if OctoPrint is still running. If you do not know how to do this, you can find the IP under the gear in the upper right corner of your printer's card inside your panel. Here you will find "Printer info" on the list. On the page that pops up, find "IP address". It is copied and pasted into the search bar of a new tab.

If the page looks like in the pictures below, it means that your Raspberry Pi is still running and connected to the internet but that OctoPrint is no longer running as it should. If you get this message, you can restart your raspberry by unplugging it and turning it on again. If this does not solve the problem, try using a different power supply for your raspberry. If it does not get enough power, OctoPrint can be rather unstable and result in crashes.

Changed Wifi name or password

The password and name of your Wifi are encoded directly into one of the files located on your raspberry. This means that if it does not find a network with exactly that name and password, it will not be able to connect to it. This also means that it cannot log in to your network if you change the name or password of your network and you must therefore enter and correct the file so that your raspberry can reconnect.

Easy way

Disconnect power from your raspberry
Remove the SD card and insert it into your computer
Open pathfinder (windows) or finder (mac) and enter the SD card
Go to https://simplyprint.io/wifi-generate and follow the instructions
Drag the downloaded file onto your SD card
Make sure it replaces the old file of the same name
Take the SD card out of your computer and put it back in your raspberry pi.
Turn on the power again

Manual way

Disconnect power from your raspberry
Remove the SD card and insert it into your computer
Open pathfinder (windows) or finder (mac) and enter the SD card
Find the file named "octopi-wpa-supplicant" and open it in a text editor
Scroll down the text a bit until you see the old name and code on your network
Write the new name and / or code where the old one is and make sure to write it in between the quotation marks ("quotation marks")
Save the document by clicking "File" at the top and pressing "Save"
Take the SD card out of your computer and put it back in your raspberry pi.
Turn on the power again