When built, this box will be able to show high/low temperature + humidity inside of your printer to give you critical information on hot/cold zones in the enclosed build area.

Code for Arduino: https://github.com/cncartist/arduino-project-box

This Arduino project box was created for a temperature/humidity monitoring system and includes space for a switch + excess wiring/sensors. The front is made to hold my LCD Project Box with a ST7735S display module. The project box comes with a separate hinged closable wiring lid which can provide quick access to the inside or allow you to put something much larger into it while keeping the lid off. The Arduino mounts to the project box via 2 M3x10mm or M3x12mm screws (depending on how much thread you want sticking out) at the top and the screw heads are counter sunk. The whole assembly hangs on the left side of the printer (right side hanger - http://www.thingiverse.com/thing:1522737), via the gap between the sheet metal. If your gap isn't large enough you can use a flat-head to pry the gap a little larger using care to not affect any other parts of the printer.

The whole project box setup takes:

Printed Parts:
1 Project Box
1 Project Box Hinged Lid
1 LCD Display Case Front (http://www.thingiverse.com/thing:1520137)
1 LCD Display Case Back (http://www.thingiverse.com/thing:1520137)
1 DHT22 Sensor Box (optional - http://www.thingiverse.com/thing:1520129)
1 DHT22 Sensor Box Cover (optional - http://www.thingiverse.com/thing:1520129)

Purchased Parts:
1 Arduino UNO (~$6)
1 ST7735S 128x160 1.8" TFT LCD (~$4)
1 DHT22/AM2302 Digital Temperature Humidity Sensor (~$3)
1 10K ohm resistor for DHT22 (~10c)
2 M3x10mm or 12mm screws + M3 nuts (~$1)

Total purchased cost ~$14

Breadboard Jumpers (20cm + 10cm):
-It can be done with the wires being soldered but since I'd like to possibly change it in the future, it's built modular

8 20cm wires F to M for LCD to Arduino
3 20cm wires F to M for DHT22 start from Arduino
3 10cm M to M intermediate (for resistor)
3 20cm F to F connecting to DHT22