Creating a Data loger room conditions to record the condition of temperature, relative humidity, and air pressure in the room becomes relatively easy. for who do not know what it actually Arduino is a programmable micro controller using a PC, due to the ease and pretty much causes Arduino community has advantages compared to the "other" micro-controller development.
Technical Spec of the data logger.
inputs. Internal and external temperature, relative humidity sensors, and air pressure sensor (barometer)
serial output via USB and LCD monochrome.
Optional LAN and micro SD.
Video 1 .Data logger: Arduino +BMP085 + SHT11+ LCD
Video 2 .Data logger: Arduino +BMP085 + LCD
Step 1: Arduino + BMP 085
BMP 085 is a pressure sensor that uses a chip made by Bosch. To connect with a bmp 085 + Arduino, Arduino can be done by connecting the 4 pin BMP 085 ,SD pin that is connected to pin A4 ,and SCL pins are connected to pin A5.And the rest remaining connected to 3.3 V >>VCC and GND connect with Arduino GDN.(Please remember that arduino using 5 V)
For Detail reference reffer this following address (including the library)
Assuming you are familiar using Arduino and Arduino IDE , the library should extract to arduino library folder , make sure the "include" file is the same as *.cpp and *. h file
I include the zip file for trouble shooting this sensor(using ada fruit library)
I purchase this sensor & arduino from www.geraicerdas.com
Step 2: SHT-11 Temperature and Arduino
To connect to Arduino a little bit trikcy SHT-11 but I made it some how especialy I already connect BMP085, You can compare temperature result between two temperature sensor.
Step 3: Nokia 5110 LCD Display
I Purchase this LCD monitor in Korea using Gmarket.com and as I now this shipped from china. There are great tutorial for this system from Ada fruit. Please remember this LCD using 3.3 V , I will consider to change using voltage converter from 5 to 3.3 v. The arrangement of pin some times diffrent but we can understand if we see two of the reffrence
Step 4: Future Works
Actually this room condition is for evaluating Air density. Using three parameter ( Ambient pressure, temperature, and RH) we can calculate Air density using Air density equation. This is very important for weight measurement that effected by air buoyancy.
To know the uncertainty of air density at room we can do average for 1 day maybe every 10 minnutes that why I planing to attach mini SD to the system.