 Hello everyone, in this video we are going to learn all about LEDs, how they work, how to interface them with prototyping boats like a wife and aunt we know and how to program them in picture blocks. Finally, we will see what wonders we can create using them. Let's begin. Getting diodes, aka LEDs are tiny light bulb like devices that blow when current passes through them. There are two important things you need to keep in mind while working with the LEDs. The first is their polarities also have positive and negative terminal and the shorter one is the negative terminal. There are current to pass only in one direction, that is, from current rating is the maximum value of the current they can withstand. If you pass the current greater than that value, they may blow up. The same value of current for LEDs is usually around 20mA. To limit the value of current, we use resistors, the value of which can be calculated using the understanding of the LEDs. Let's have a look at how to evive already has an LED connected to focus on writing scripts to control it here. If you want to control an external LED, you can make a circuit like this on evive's breadboard and connect the positive terminal of the LED to a digital pin through which you want to control the LED. Now, let's program the pin as a graphical programming software based on scratch blocks. You can download it from the link given in the description box below. In the box that appears, choose the appropriate serial code, select hide from the second drop down menu, hit up once again. Duplicate the script and place it below the main block, above the horrible block. It will ensure that the script running or not by running the script. Let's make another script to control the brightness of the LED in real time. To control the brightness, we will use pulse width modulation. It is a technique to reduce the FH voltage at the digital pin by controlling the width of the digital pulse at that pin. Let's make a variable to control the brightness and place it in the blank space of the set PWM pin block. Let's have a look at the output while running the script. Let's try the script to make the LED blink in the upload mode so that we can work with evive without it being connected to the computer, above the entire script to execute the program.