Human beings need eyes to see, ears to listen, nose to smell that is we need things to sense the outer world. The same with Arduino, it needs the sensors to take sense inputs. But what are these Sensors?
They generate analog output values corresponding to the real world’s action. Here is some brief list of some of the sensors:
- Accelerometer: They Detect tilting. They are also used in Mobile Phone’s (even in yours) for Playing games.
- Magnetometers: They detect magnetic field (used for making digital Compass, can also be used as Metal detectors).
- Infrared Sensor: They detect distance to the object.
- Temperature Sensor: They can tell you about the temperature.
As far as you have read about sensors you might be knowing their name. You need to understand that they are nothing different than other electronics components. We may call them sensors because they might be changing their voltage corresponding to the outer world response. Likewise, a temperature sensor changes its resistance with change in temperature.
Resistance changes according to this Law:
So we can get an overview of the change in temperature by calculating the change in resistance.
The sensor's sensitivity depends on how much the sensor’s voltage due to outer world behavior changes. If a sensor changes its value very frequently corresponding to outer changes then it will be having high sensitivity.
- sensitive to the measured property,
- insensitive to any other property (like sound sensor insensitive to infrared light),
- doesn’t alter the measured quantity (like thermometer doesn’t lower the temp of thing you measure with it).
We will be using different Sensors to build our Projects So You need to get familiar with some of these.