# Sensors and actuators

### Sensors

A **sensor** is an object capable of **detecting physical or chemical quantities** and transforming them **into electrical signals.**

Depending on the type of the electrical signal produced they can be **DIGITAL, ANALOG or DATA.**

- **DIGITAL**: a digital sensor only has two states: activated/disactivated, ON/OFF, 1/0, High/Low. E.g: An electronic pushbutton is a kind of simple digital sensor with two possible states: pushed or not pushed.[![boton-pulsador-1.jpg](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/boton-pulsador-1.jpg)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/boton-pulsador-1.jpg)
- **ANALOG**: This sensor can provide a range of values, normally a variable voltage or current value, depending on the signal detected. E.g: A LDR decreases the value of its resistance with an increment of light detected.[![Light-Dependent-Resistor.jpg](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/light-dependent-resistor.jpg)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/light-dependent-resistor.jpg)
- **DATA**: the sensor offers its information through a communication interface. E.g: DHT11 sensor measures temperature and humidity.[![2022-04-13-19-27-43-proyecto-00-conocemos-arduino-pdf-google-drive.png](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/2022-04-13-19-27-43-proyecto-00-conocemos-arduino-pdf-google-drive.png)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/2022-04-13-19-27-43-proyecto-00-conocemos-arduino-pdf-google-drive.png)There are lots of different sensors. To get further information click on [here](https://libros.catedu.es/books/programa-arduino-mediante-codigo/page/sensores).

### Actuators

An **actuator** is any device capable of **performing actions** in the physical world that we **can control** from a processor board (like Arduino)

Depending on the type of action produced they can be:

- **LIGHT**: The most common is the **normal LED**, but there is also RGB LED's, neopixel lightsaber, laser or LCD displays

[![imagen.png](https://librosprofes.catedu.es/uploads/images/gallery/2024-04/scaled-1680-/rK9imagen.png)](https://librosprofes.catedu.es/uploads/images/gallery/2024-04/rK9imagen.png)

- **SOUND**: There are active and passive **buzzers**. Active buzzers play a tone of a frequency determined when they receive a digital "1" whereas a passive buzzer only plays the wave that receives.

[![active-buzzer-or-passive-buzzer.jpg](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/active-buzzer-or-passive-buzzer.jpg)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/active-buzzer-or-passive-buzzer.jpg)

- **MOTION**: There are different types of motors depending on their properties. They usually need auxiliary elements to be controlled by processor boards, because of the voltage they require.

[![Featured-Image.webp](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/featured-image.webp)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/featured-image.webp)

### Imagina TDR Steam shield  


We will use in our projects one shield called **Imagina TDR Steam** which is integrable into Arduino UNO, with a multitude of integrated sensors and actuators.

[![placatdr.png](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/scaled-1680-/mhPplacatdr.png)](https://librosprofes.catedu.es/uploads/images/gallery/2024-03/mhPplacatdr.png)

<table border="1" id="bkmrk-sensor%2Factuator%2Fmodu" style="border-collapse: collapse; width: 100%; height: 447px; border-width: 5px;"><colgroup><col style="width: 7.59604%;"></col><col style="width: 92.404%;"></col></colgroup><tbody><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">  
</td><td class="align-center" style="height: 29.8px; border-width: 5px;">**Sensor/Actuator/Module**  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">1  
</td><td style="height: 29.8px; border-width: 5px;">Two pushbuttons (SW1, SW2)  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">2  
</td><td style="height: 29.8px; border-width: 5px;">Two LEDS (Blue Led3 and Red Led4)  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">3  
</td><td style="height: 29.8px; border-width: 5px;">Led RGB  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">4  
</td><td style="height: 29.8px; border-width: 5px;">DHT11 Temperature and Humidity Sensor  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">5  
</td><td style="height: 29.8px; border-width: 5px;">Buzzer  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">6  
</td><td style="height: 29.8px; border-width: 5px;">Two digital outputs/inputs  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">7  
</td><td style="height: 29.8px; border-width: 5px;">Infrared receiver module (IR)  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">8  
</td><td style="height: 29.8px; border-width: 5px;">Rotary potentiometer module  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">9  
</td><td style="height: 29.8px; border-width: 5px;">Light sensor (LDR)  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">10  
</td><td style="height: 29.8px; border-width: 5px;">Temperature sensor (LM35)  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">11  
</td><td style="height: 29.8px; border-width: 5px;">I2C Interface  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">12  
</td><td style="height: 29.8px; border-width: 5px;">Analogic input</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">13  
</td><td style="height: 29.8px; border-width: 5px;">Bluetooth and Wifi connection  
</td></tr><tr style="height: 29.8px;"><td style="height: 29.8px; border-width: 5px;">14  
</td><td style="height: 29.8px; border-width: 5px;">Reset button  
</td></tr></tbody></table>