Soil Humidity and temperature sensor - DHT1010

[epierre]

Another try to see if I can find one that can be immerged in the soil. It is very cheap, and can be found on some places at sometime a high price. Here is the cheap one.

Now the hard part: how to find information.

HUMIDITY SENSOR : Blue and Green wire
TEMPERATURE SENSOR: Brown and White wire
No polarity seems to apply. i will connect it with 1.5V and measure the voltage drop in various conditions. Hope it is usefull info 

Do you think I could use the DHT1x lib to read it ?

[Yveaux]

@epierre Judging from the comments on dx.com (which aren't very positive...) there are two sensors in there. Both seem to be resistive and someone claims it is a HR202: http://www.cytron.com.my/usr_attachment/HR202 Humidity Sensor.pdf

If this is true, the sensor will not be compatible to DHT1x, which outputs a digital signal.
The temperature sensor is probably an NTC or PTC (measure the resistance at some different temparatures to find out its characteristic).
Then you can use the matrix in the datasheet to look up the RH given the resistance of the humidity sensor and temperature.

Unless you need a bunch of these sensors I would recommend to buy a decent one, with a datasheet (or even one supported by an Arduino library) to save yourself a lot of trouble...

[epierre]

@Yveaux you are right, the worse is when I open it... I see this is not waterproof at all and...