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# Enabling filament sensor detection for your printer in SimplyPrint

If your printer has a filament sensor, SimplyPrint can show when the printer has no filament loaded. This guide covers how to turn it on, what OctoPrint needs, and what SimplyPrint shows once it is on.

## In this guide
* [Turn on the filament sensor](#2-turn-on-the-filament-sensor)
* [OctoPrint: install the filament sensor plugin](#2-octoprint-install-the-filament-sensor-plugin)
* [What SimplyPrint shows](#2-what-simplyprint-shows)
* [When the filament runs out during a print](#2-when-the-filament-runs-out-during-a-print)
* [Related articles](#2-related-articles)

## Turn on the filament sensor
|| Printer settings can only be changed in the web panel, and only by members allowed to edit printer settings.

1. Open the printer's settings. See [Finding the printer settings](https://help.simplyprint.io/en/article/finding-the-printer-settings-17tbtqt/).
2. Go to the **Modifications** tab and click **Filament sensor**.
3. Tick **Printer has a filament sensor**.
4. Click **Save changes**.

Check: open the settings again and **Printer has a filament sensor** is still ticked.

| You may find it already ticked. When a printer's connection reports a filament sensor to SimplyPrint, SimplyPrint turns this setting on by itself.

## OctoPrint: install the filament sensor plugin
On OctoPrint, SimplyPrint uses its own SimplyFilamentSensor plugin for a sensor connected to the Raspberry Pi. When you tick the setting and the plugin is missing, SimplyPrint shows **Needs an OctoPrint plugin**.

1. Make sure the printer is online and not printing.
2. Click **Install filament sensor plugin**.
3. When the install has finished, set up the filament sensor in the plugin's settings in OctoPrint.

Check: open the **Filament sensor** settings again. The **Needs an OctoPrint plugin** message is gone.

## What SimplyPrint shows
* **On the printer card:** when the printer is online and the sensor detects no filament, a red icon appears in the corner. Its tooltip reads "This printer has no filament detected by the filament sensor".
* **In the printer list filters:** **Has filament sensor** finds printers with the setting on, and **Filament sensor has** finds online printers where the sensor detects filament.

## When the filament runs out during a print
SimplyPrint does not pause the print itself. The pause comes from your printer's firmware, or from the filament sensor plugin on OctoPrint. Once the printer pauses, SimplyPrint shows the print as paused. Load new filament, then resume the print.

To be told when this happens, turn on both **Pause of print** and **Pause on filament runout while printing (filament sensor)** in your [print notifications](https://help.simplyprint.io/en/article/print-notifications-get-alerted-by-email-sms-or-app-push-9xzbnh/).

If the sensor works when you print from the printer's own screen but not through SimplyPrint on OctoPrint, see [Filament sensor not working with SimplyPrint or OctoPrint](https://help.simplyprint.io/en/article/filament-sensor-not-working-with-simplyprint-or-octoprint-1mv511c/).

## Related articles
* [Finding the printer settings](https://help.simplyprint.io/en/article/finding-the-printer-settings-17tbtqt/)
* [Filament sensor not working with SimplyPrint or OctoPrint](https://help.simplyprint.io/en/article/filament-sensor-not-working-with-simplyprint-or-octoprint-1mv511c/)
* [Print notifications: get alerted by email, SMS, or app push](https://help.simplyprint.io/en/article/print-notifications-get-alerted-by-email-sms-or-app-push-9xzbnh/)
* [Enabling PSU control](https://help.simplyprint.io/en/article/enabling-psu-control-power-supply-via-gpio-gcode-etc-in-simplyprint-1xtopb6/)