====== Sensors and Sensing ======
{{:en:iot-open:czapka_p.png?50| General audience classification icon }}{{:en:iot-open:czapka_b.png?50| General audience classification icon }}{{:en:iot-open:czapka_e.png?50| General audience classification icon }}\\
A sensor is an element that can turn a physical outer stimulus into an output signal, which can then be used for further analysis, management, or making decisions (figure {{ref>sensor}}). People also use sensors like eyes, ears and skin to gain information about the outer world and act according to their aims and needs. Sensors can be divided into many categories according to the measured parameter of the environment.

<figure sensor>
{{ :en:iot-open:getting_familiar_with_your_hardware_rtu_itmo_sut:arduino_and_arduino_101_intel_curie:sensor2.png?400 | Environment sensing data flow}}
<caption>Environment sensing data flow</caption>
</figure>

Usually, every natural phenomenon – temperature, weight, speed, etc. – needs specially customised sensors that can change phenomena into electric signals, usually the voltage, that microprocessors or other devices could use. Sensors can be divided into many groups according to the physical nature of their operations – **touch**, **light**, an **electrical characteristic**, **proximity** and **distance**, **angle**, **environment** and other sensors.

<WRAP excludefrompdf>
In the following chapters, there is a deeper description of each class of devices, along with samples:
  * [[en:iot-open:hardware2:sensors_touch]],
  * [[en:iot-open:hardware2:sensors_light]],
  * [[en:iot-open:hardware2:sensors_optical]],
  * [[en:iot-open:hardware2:sensors_electric]],
  * [[en:iot-open:hardware2:sensors_distance]],
  * [[en:iot-open:hardware2:sensors_angle]],
  * [[en:iot-open:hardware2:sensors_environment]],
  * [[en:iot-open:hardware2:other_sensors]].
</WRAP>