I’ve tried the DHT11 sensor modules at both Vcc 3.3V and 5.0V, and at both voltages the humidity values are bad. dfrobot has introduced a V2 DHT11 sensor module that changes the 10K pull-up to 4.7K.

It features over 5,400 projects, ranging from simple tutorials — like using a soil moisture sensor with Arduino — to more complete guides like building a Bluetooth-controlled car.

You'll need an Arduino along with a bunch of various sensors to get the project rolling, and once it's all set up you'll have a simple, but cheap system to monitor your home. Head over to ...