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English:
Hello,

i have an question. I am using an Arduino MegaADK(http://www.watterott.com/de/Arduino-ADK-Rev3) with the Electronic Brick Starterkit(http://www.watterott.com/de/Electronic-brick-Starter-kit).
When I make an analogread at the pin where the temperature sensor ist connected the returned value ist 44. But what I need is the temperature in celsius degree. I think in my room it's between 20-25 degree. How can I convert the returned value to celsius?

I'm afraid that i can't find a datasheet for the sensor. May be someone can help me to convert the teturned value to celsius?

Regards Micke

German:
Hallo,
ich arbeite mit dem Arduino MegaADK(http://www.watterott.com/de/Arduino-ADK-Rev3) und nutze die Bauteile aus dem Electronik Brick Starterkit(http://www.watterott.com/de/Electronic-brick-Starter-kit). Momentan möchte ich gerne den Temperatursensor aus dem eben genannten Starter Kit verwenden um die Raumtemperatur zu messen.
Leider habe ich kein Datenblatt zum Sensor gefunden, so dass ich weder den Messbereich noch die Einheit kenne. In meinem Arbeitszimmer ist der Returnwert des analogread(temperature) zurzeit 44. Da ich im T-shirt angenehm hier sitze nehme ich mal an die Tempearatur liegt zwischen 20 und 25 °C. Wie muss ich die 44 umrechnen um auf die genaue Temperatur in °C zu kommen?  Kann mir evtl. jemand die Umrechnung erklären?

Gruß

Micke

[Reply #1 on:]

I cannot determine what temperature sensor the kit contains. Some sensors are digital and use 1,2 or 3 data pins depending if they are Dallas 1-Wire, TWI (I2C) or SPI. Other are analogue, normally using only one analogue pin to take readings.
Looking at the cookbook the temperature sensor may be analogue but it would really help if we knew the make/model of sensor.
Reading analogue you could get values between 0 and 1023 and this number in some way corresponds to the temperature but without knowing the sensor the values are of little help unless you calibrate it against know temperature readings.
For example lets say the sensor reads 20 at 0 degrees Celsius and 1020 at 50 degrees. You can interpolate the values to work out the temperature (assuming readings are linear) for any value in between as the number will increase by 20 per degree.

[Reply #2 on:]

The Wiki of the brick : (bit empty) http://www.seeedstudio.com/wiki/Electronic_brick_-_Temperature_sensor%28Analog%29
This is the datasheet of the NTC, http://www.seeedstudio.com/depot/images/product/TTC03.pdf

search for "thermistor"  in the arduino.cc playground,  you'll get a few good pages on how to convert to Degrees

[Reply #3 on:]

In the datasheet I can find different part no's. Where can I find the part no of my thermistor?

[Reply #4 on:]

You can measure the resistance at 25Celcius, that will give you a good entry point for the datasheet.
Try Seeedstudio Forum,  they sold this to you, they should know.
Find example code for this brick.