A simple rotary encoder for all your projects.
It's like a potentiometer, but without end. It sends pulse to your microcontroller to let you know in which direction it turned. This version also has a button.
If you are searching an ultrasonic ranging module, the HC-SR04 is good choice: Its stable performance and high ranging accuracy make it a popular module in electronic market. It's cheaper than an IR range finder with similar range accurancy and distance.
The DS18B20+ is a programmable resolution 1-wire digital thermometer in 3 pin TO-92 package. This digital thermometer provides 9bit to 12bit celsius temperature measurements and has an alarm function with non-volatile user programmable upper and lower trigger points. The DS18B20 communicates over a 1-wire bus that by definition requires only one data line...