Video introduction to hardware interfacing on the Raspberry Pi four. In this video, we will look at the essential tools to start with hardware interfacing. Later, we will learn about the GPIO zero library. And finally, we interface an LED with the pie and work with it. Before you start your pie hardware journey, you will need some essential tools other than sensors and actuators. During the learning phase, you would want to change circuits easily for different projects.

Thus, a breadboard is an essential tool, which makes circular dismantling and reconfiguring a breeze. a breadboard cannot obviously be connected to the Raspberry Pi for without wires. Thus, we need a lot of jumper wires. The next important tool to have is a multimeter. A typical inexpensive multimeter will feature a digital display and a rotary selector Switch for various voltage, current and resistance ranges. Once you finish this course, you will be off to building your own projects.

At that time, you wouldn't want to use the breadboard still, you will need a more permanent solution, so it's better to buy a soldering iron kit. If you don't know how to work with breadboards multimeters or soldering iron, please check out the links in the resources and learn. Now let's look at some of the software essentials before moving on. GPIO zero is a friendly Python library for physical computing. GPIO zero started out as a friendly API on the top of the RPA dot GPIO. RP IO and pi GPIO library, but later was extended to allow other pin libraries to be used.

GPIO zero comes preloaded with support for many common sensors and actuators Thus, this GPIO library is very user friendly. This library uses Broadcom pin numbering for the GPIO pins, as opposed to physical numbering. For those who don't know about the RPI GPIO library, please check out the links in the resources to know the importance and impact it had on the PI community. GPIO zero is shipped as part of the default Raspbian distribution. It's simple interface takes you straight to the hardware, with a minimum of other code required, and it has built in support for a huge array of sensors and output devices. The first step is to make sure that your GPIO zero library is up to date.

Go to the terminal and type sudo apt update and then sudo apt install Python three Hi friend GPIO zero. So, shall we start off with controlling an LED project on the PI. In the simplest terms, a light emitting diode is a semiconductor device that emits light. When an electric current is passed through it. Light is produced when the particles that carry the current known as electrons and holes, combined together within the semiconductor material. Inside a semiconductor material of the LED, the electrons and holes are contained within energy bands.

The separation of the bands determines the energy of the photons, which determines the wavelength of the emitted light, enhance its color. Different semiconductor materials with different band gaps produce different colors of light. Now we will use a red LED. If you look at an LED, you can see two legs the longest One is called an old or the positive leg and the shorter one is called cathode, which is the negative leg. See, LED is a delicate little things. If you force too much current through them, they will sometimes pop quite spectacularly.

To limit the current going through the LED, you should always use a resistor in series with it. This type of resistor is called as a current limiting resistor. The choice for the current limiting resistor also is determined by the forward voltage of the led the supply voltage and the forward current which is dependent on the color of the LED. Thus, by ohms law with a supply voltage of 3.3 volts of forward current of 20 milli amperes and forward voltage of two volts. Any current limiting resistance about 65 ohms is fine. If you want to know more about current limiting resistors and how to choose them Please check out the resource section.

First connect and fix the LED on the breadboard. Now can it be 180 ohm resistor in series with the anode of the LED, connect a jumper wire from the other leg of the resistor to a 3.3 volts pin on the boat. Finally, connect a jumper wire from the cathode like to a G in the pin on the board. The LED should light up, it will always be on because it's connected to a three v three pin which itself is always on. Now move it from three v three to GPIO pins 17. The LED should now turn off but now it's on a GPIO pin and can therefore be controlled by code the open Tawny Python ID and type the following in the shell from GPIO zero input LED.

First, we have to import the GPIO zero library as well. We need only the LED class from the GPIO zero library. Next type led equals led of 17. The parameter 17 inside the LED class tells the PI which GPIO pin we are using. In this case, it's 17. by assigning the class to a variable named LED, you have created an instance of this class, also called an object. Now to make the LED turn on, you just need to call the own function inside the LED class, which has now access to where the object led does entering led.on and pressing Enter will light up the LED.

Similarly, on entering led dot off, it will switch off but that's not much fun, right. With the help of the time library and a little loop, you can make the LED flash download the Add underscore bling dot p y from the resources and open it in In the Tony ID, you can see that we have inputted a new class from the time library called sleep. Also, we have made an infinite loop with the wild true instruction inside which we have used the sleep method to make the LED turn on and off at one second intervals. Now run the script and you will see the LED blinking summary. In this video, we have covered the following essential tools for hardware interfacing, the GPIO zero library interface and working with an LED using Python. In the next video, we will learn and work with p w m in LCDs.

And working with buttons