Tardis CO2-Sensor with Display

This is the Tardis of Dr. Who equipped with a display and a CO² sensor. You can use it e. g. in the office to indicate the need for ventilation.

I am using a high quality CO² sensor. It uses the NDIR measurement technology. More information can be found here.

Tardis

As base I have used this thing.
Print the following parts from there:

• Base (either ring or solid)
• Panel with door
• Panel (2x)
• Window (2x)
• Top ring
• Roof
• Lamp shade

Lamp top From here you need to print

tuer_display

befestigung_display

Electronics

Following parts are needed

Wemos D1 mini

• Sensirion SCD30 CO2 sensor
• 2.2 '' display ILI9340

Micro-USB cable There are three holes on the back of the modified door. The bracket can be glued to these holes to fix the display. The pins of the display are up.

Only two doors are equipped with windows to allow some ventilation. I have glued the sensor with the connection pins to the open window opposite of the display.

Wiring

Sensirion -> Wemos D1 mini

VIN -> 5V

• GND -> GND
• SCL -> D1

SDA -> D2 Display -> Wemos D1 mini

SDO -> D6

• LED -> 3V3
• SCK -> D5
• SDI -> D7
• DC -> D3
• RESET -> RST
• CS -> GND
• GND -> GND

VCC -> 3V3

Software

Install following libraries in your Arduine IDE:

Adafruit GFX

• Adafruit ILI9341

TinyWireM Compile and upload the sketch display_hochkant.ino to the Wemos D1 mini.

Here you can find more information on the display in German.

And on this Github repository you can find other sample code for the CO² sensor.

To assess the measured CO² concentration this page was helpful for me (in German).

Have fun with the Tardis!

Print Settings

Resolution: 0.10

Infill: 15%

Filament: DasFilament: Signal Blue, natural