MAX7219 (x4) case (tool-free assembly) with different ESP board holders

Initially I wanted to create a simple clock for the living room which also shows the temperature outside and then I found: 

The creator did a great job with the firmware (I really like the firmware on github!!!) but I was not happy with the case because I didn't like how the diffusor should be held in place and because there no mounting bracket or something equal provided for the ESP board.

I also found no other suitable case, that's why I decided to create my own case which could be used for any MAX7219 display project.

The focus during the construction was on easy printing with less support as possible, easy assembly (tool-free) and variable holders for different ESP boards.

I constructed holders and back panels for the Wemos D1 Mini (ESP8266), the Wemos D1 Mini Pro, the ESP32 D1 Mini and the ESP32 DevKit.

For the diffusor I'm providing 3 files with different thickness. For the black PLA I used, 0.2mm worked out best because it is translucent enough and still has a closed surface (concerning layer lines). Be sure you have a good first layer quality on your printer. If you use brighter, colored or even white PLA, you could try 0.4mm or 0.6mm.

In summary you have to print 5 parts without any special printer settings (0.4mm nozzle, 0.2mm layer height). Here are some assembly instructions:

1. Connect the MAX7219 shipping included cables to the MAX7219 board and place the matrix module in the case.

2. Put the diffusor on top of the matrix module and snap-in the frame on top.

3. Connect the cables, coming from the matrix module, to the ESP board (pin assignment depends on the used board and how you possibly configure the pins in the firmware source code yourself) and snap-in the ESP board in the holder.

4. Slide-in the holder from the back into the case.

5. Snap-in the back panel.