1) DHT11/DHT22 Temperature and Humidity Sensor These DHTXX sensors are very popular among the Arduino Tinkerers. The DHT sensors are inexpensive sensors for measuring temperature and humidity. These sensors contain a chip that does analog to digital conversion and spits out a digital signal with the temperature and humidity. Specifications DHT11 vs DHT22 There are two versions of the DHT sensor: DHT11 Range: 20-90% Absolute accuracy: ±5% Repeatability: ±1% Long term stability: ±1% per year Price: $1 to $5 DHT22 Range: 0-100% Absolute accuracy: ±2% Repeatability: ±1% Long term stability: ±0.5% per year Price: $4 to $10 As you can see from the specs above, the DHT22 is a bit more accurate. Arduino with DHT11 Sensor For this example you need the following components. Arduino UNO 1x DHT11 Breadboard 10KΩ Resistor (or 4.7KΩ) Jumper Wires Schematic Here’s ho...