3D Printer Monitor With LCD for Up to Four 3D Printers (via Wifi or Octoprint)

This is a standalone device that you can place in the living room or another room away from your 3D printer(s) to monitor the current status of 3D prints. It can monitor four 3D printers simultaneously. These can be printers connected with Octoprint or standalone Prusa printers connected to your Wifi network.

Hardware: WeMos D1 Mini, tumbler switches (1 for every 3D printer), a buzzer for 3,3V and an I2C LCD.

Tools: a 3D Printer

Software: Arduino IDE with libraries: LiquidCrystal_I2C and ArduinoJson.

Download the OpenScad file and create STL's from it to make the enclosure. Print the enclosure on your 3D printer. It consists of the following parts (see the OpenScad source): front panel, body, back panel and feet.

The front panel has room for a standard 16x2 I2C LCD and 4 holes for 4 tumbler switches. Every printer has one switch and you can use up to 4 switches. You can use brass threaded inserts with M2.5 bolts to tighten the front and back panel.

Prepare the electronics (LCD and switches) according to the schematic. Use as many tumbler switches as you have printers. Wire the LCD's SDA to D2 of the D1 Mini and the LCD's SCL pen to the D1 of the D1 Mini.

Download the 3DPrintMonitor.ino file and edit it first.

Set the SSID and the password of your Wifi network in the file and also set the IP addresses of your printers in the file. Then program the D1 Mini with the edited file.

After programming the D1 Mini the system becomes functional and starts showing stuff on the LCD. You may need to adjust the potentiometer on the back of the LCD to set the contrast right. If nothing is shown on the LCD or you see a single bar of blocks then the I2C address is not 0x27. Use a I2C Scanner sketch to determine the address of the LCD and set it in the software (line 35 of the code).

Use the tumbler switches to set which printers you want to monitor. You can monitor up to 4 printers at the same time. The buzzer beeps as soon as a printer needs attention. When you use the trick to print in multiple colors the device warns you with a beep that the printer is waiting for you to change the filament. If your printer has a filament sensor and it can detect an out-of-filament status the device will also beep and show this on the LCD.

Start printing and watch the device automatically show the file name of the printed object, the name of the printer, the tool temperature and the completion as a percentage.