Thermometer screen for the senseBox

When searching for the ideal location of the senseBox the idea came to use a well-tried weather hut and to measure the temperature in 2 meters height.

The thermometer screen made of wood according to Stevenson is a suitable radiation protection for the temperature / humidity sensor of the senseBox. Laminated housing walls and door provide good ventilation and protection against direct and reflective solar radiation. The weather hut made of wood was painted white inside and outside for optimal heat radiation protection.

This project was realized and documented by one of our community members! The author is OllyS and like many others can be found in the senseBox forum. In the forum you will also find suggestions, new ideas or discussions about the senseBox!

Materials

senseBox MCU (Outdoor Case, Power supply and cable, temperature & relative humidity sensor, Wifi-Bee). Source of supply senseBox Shop
Sensors (Air pressure & temperature, illuminance & UV radiation, fine dust (PM10 & PM2.5). Source of supply senseBox Shop
Weather house (Kit raw or painted) Source of supply Stiftung zur Palme
needed accessoires
- device connector IP68 4Pol Distrelec:300-47-767 (3)
- cable connector IP68 4 Pol Distrelec:300-47-727 (3)
- Data cable unshielded 3x 2x0.25mm² Distrelec:155-73-712
- I2C-I2C cable Watterott: (3)
- Nova SDS011 senseBox connection cable - 350mm Watterott (1)
- USB-rifle panel-contact micro-USB B Distrelec:301-03-704 (1)
- Pressure compensation element GR M12x1.5 Distrelec:150-15-938 (1)
- Plastic housing 65x115x40mm light gray P Distrelec:300-64-459 (1)
- Distance bolts 20mm 5mm Distrelec: 110-76-305 (4)
- Countersunk screw M2.5 x 8mm (4)
- Screw nut M2.5 (4)
- Heat shrink tubing 2.5 mm

Installation

The senseBox MCU Home already offers a good weather resistance and can be used without modifications "outdoor". In order to ensure the air flow of the PM2.5 / 10 sensor, an additional hole is made in the housing. In order to prevent insects from boarding the housing, the air inlet and the bore are protected with a piece of insect screen.

Step drill
Insect screen

Because of the service friendliness (replacement of individual components during operation) the boxes of the individual sensors are each provided with longer cables and waterproof plugs. In the MCU housing, a waterproof pressure compensation element was installed and the brightness / UV sensor was housed in its own housing.

4 Pol Stecker löten

In order to avoid extraneous light scattering on the SDS011, the transparent suction hose was wrapped with insulating tape.

For power supply and maintenance (Sketches) a waterproof micro-USB socket was installed in the MCU housing.

Assignment of sockets and plug

M16 Panel Mount Micro USB 2.0 - Type B

Here we solder a Micro USB cable, practically an extension to the MCU.

Pin 1 = 5 Volt (red)
Pin 2 = Data - (white)
Pin 3 = Data + (green)
Pin 4 = ID (unused)
Pin 5 = GND (black)
Pin 6 = Shield (shielding)

4 pole device connector IP68 I2C

Here, a fully configured I2C cable is cut in the middle and soldered to the socket, the individual contacts are protected with shrink tubing. The other end is plugged into the MCU board to an I2C connector.

Pin 1 = GND (Ground) black
Pin 2 = VCC (+5 Volt) red
Pin 3 = SDA (Data) green
Pin 4 = CLK (Clock) yellow

4 pole device connector IP68 UART/Serial (PM2.5/PM10 Sensor)

Here, the SDS011 senseBox connection cable is disconnected in the middle, and the part with the small plug soldered to the socket. The other half of the cable is soldered to the data cable in the particulate matter sensor housing (Figure 6 & 7).

The pin assignment of the fine dust sensor connector:

Pin 1 = GND (Ground) black
Pin 2 = Tx (Transmit from Host) white
Pin 3 = Rx (Receive from Host) blue
Pin 4 = VCC (Power 5V) red

Assembly

The hut construction kit from Stiftung zur Palme Stiftung Palme is a good carpentry and everything fit together easily. To prime the hut and paint it with gloss paint it took about 4 hours. You can order them also painted for an additional charge.

The MCU and the air quality sensor have also been put into the cabin for the sake of simplicity.

The hut was attached to a 11x11 cm wooden post, the temperature sensor is located at about 2 meters above the lawn. It was fastened with a piece of plastic pipe and a piece of balsa wood.

The single-leaf, lockable door faces north, the brightness and UV sensor to the south..

All data is sent by the senseBox via wifi to a router in the house and from there to openSenseMap. Informations: https://opensensemap.org/info

Planned extensions:

Autonomous operation with solar panel, battery and LoRa-Bee.
Measuring unit for wind direction, wind speed and rainfall.

Literatur

Kopp M. (2012): Vergleich verschiedener Wetterhütten zur Messung der 2m-Lufttemperatur in Abhängigkeit von Wind und Strahlung. Link

German Weather Service: Vorschriften und Betriebsunterlagen Nr. 3 (VuB 3) TECHNIKHANDBUCH (THB) für Wettermeldestellen des synoptisch-klimatologischen Mess- und Beobachtungsnetzes

Weblinks:

Verein GLOBE Schweiz: Wetterhaus https://www.globe-swiss.ch/de/Zyklus3/Angebote_Wetter_und_Atmosphare/Atmosphere/Wetterhaus/

Thermo Hut