What is a Microcontroller?

The microcontroller is considered as the backbone of Embedded Systems(please read it once, before moving forward) & its most important feature is: "It can think". A Microcontroller looks like a simple electronics chip, but in actual it's too powerful (also called Embedded Computer) because it's programmable. Using programming code, we can control all I/O pins of a controller and can perform multiple functions (We will discuss them later). Before microcontrollers, DLD gates were used to create logics i.e. adding delays, turning signals ON/OFF etc. DLD is still in practice for small projects but if you are working on big industrial projects, then DLD circuits become too messy & thus too difficult to handle. In the below figure, I have added two circuits of traffic signal lights:

• Left Circuit: 555 Timer is used for creating the LED sequences.
• Right Circuit: Microcontroller is used for controlling LEDs.

As you can see, the DLD circuit is quite messy as compared to the microcontroller one. Moreover, the 555 Timer circuit is controlling 3 LEDs only, if we want to add more LEDs, we have to replicate the circuit, thus more components, so it won't be cost-efficient. On the other hand, a single microcontroller can easily control 4 sets of traffic lights, as shown below the image and it can still control a lot more. Moreover, Microcontroller's circuit is too simple, easy to handle/debug.

                              Microcontroller Programming