How it's made

Physical computing

Physical computing

Basic electronics and circuits

Basic electronic components and sensors

Sensors and Actuators

Sensing

we often construct our reality using our sensory experience:

our visual and sound come from our eyes and ears, we can feel the moisture level on our skins, we can feel the gravity and orientation thanks to our inner ear structures.

and now imagine all the sensory input can be converted into digits and feed to a computer, and the computer device can decide what to do(output) with the input data. let's look back to the Shannon-Weaver model of communication.

there is so many already made sensor module for Arduino. Many sensors can detect signals or pick up data beyond human senses. For example ultrasonic sensors. Imagine we can use these sensor technologies to expand our senses and "reality".

Back to the Sensors: In General, there are two types of sensors: analog and digital.

The analog sensor can detect a range of data. (for example from 0-1020)

The digital sensor can detect either 0 or 1. (or HIGHT /LOW).

for better understanding: the analog sensor is like a dimmer and the digital sensor is like a normal switch.

Here is a list of sensors and examples:

'''Comment sensors:'''
 Don't need additional libraries, normally included in Arduino's example tutorials.

 Potential meters: AnalogReadSerial
 Botton or switch: Button
 Ultrasonic sensor: Ping
 Mic or piezo: knock
               toneMultiple

 Flex & force sensor: toneKeyboard
 LDR (Light Dependent Resistor):
 Calibration
 tonePitchFollower

'''Advanced sensors:'''

 Need to install additional libraries.

 Capacitive Sensor-Analog : adafruit-cap1188-breakout
 Or touch-board
 Pulse sensor(heart rate): pulsesensor
 UV sensor:  uv-index-sensor
 Gyroscope/acceleration meter:Gyroscope/acceleration

Relay Module

Introducing the Relay Module

A relay is an electrically operated switch. It means that it can be turned on or off, letting the current go through or not.

Controlling a relay with the Arduino is as simple as controlling an output such as an LED.

Notice the writing on the module terminals

COM: common pin
NO (Normally Open): there is no contact between the common pin and the normally open pin. So, when you trigger the relay, it connects to the COM pin, and supply is provided to a load
NC (Normally Closed): there is contact between the common pin and the normally closed pin. There is always a connection between the COM and NC pins, even when the relay is turned off. When you trigger the relay, the circuit is opened and there is no supply provided to a load.
If you want to control a lamp, for example, it is better to use a normally open circuit, because we just want to light up the lamp occasionally.

Wiring

it is very straightforward as you can see. But always double-check the relay module connections before you plug things together.

GND: goes to ground
VCC: goes to 5V
IN1: controls the relay (it is connected to an Arduino digital pin)