#Usart serial communication protocol serial

It can be seen from the following diagram that clock skew and crosstalk are inevitable.

Crosstalk:В Phenomenon by which aВ signalВ transmitted on one channel of aВ transmission bus creates an undesired effect in another channel.В Undesired capacitive, inductive, or conductive coupling is usually what is called crosstalk, from oneВ circuit, part of a circuit, orВ channel, to another.

Clock skew is inevitable due to differences in physical conditions of the channels, like temperature, resistance, path length, etc This is better illustrated in the picture below: There is a time lag in the data bits through different channels of the same bus. This time difference is what we call clock skew. When, say around 5 people are firing at the same time, there is bound to be a time difference in the arrival of the bullet from the first shooter and that from the second shooter and so on.

Clock Skew: In a parallel circuit, clock skew is the time difference in the arrival of two sequentially adjacent registers.В To explain it further, let us take the machine gun example again.

Bit Rate: It is the number of bits that are transmitted (sent/received) per unit time.

But wait, these are just the basicВ differences.В Before we proceed further, we need to be acquainted with a few terminologies:

#Usart serial communication protocol serial

From the above differences, one would obviously think that parallel communication is far better than serial communication. So these were the basic differences between serial and parallel communication.

Well, this is why communication is required! And to answer all those questions, several communication protocols have been developed! Now lets discuss a little about serial and parallel communication. The same questions can be put forth here as well вЂ“ how is it send, from where is it sent and to where, what is being sent and how is it processed?! IR is obsolete, NFC is still in developmental phase and isnвЂ™t available in most devices, LAN needs a WiFi/LAN network whereas email requires an active Internet connection. You have a file in your mobile and you would like to share it with your friend who is sitting next to you? How would you do it вЂ“ Bluetooth, IR, NFC, LAN or email? Mostly people would use Bluetooth. As grown ups, there are a few more questions which should arise! Like how does the device send the signal? From where is the signal being sent? What is actually being sent? Who receives it? How is it processed? Correct! So far so good, but now it doesnвЂ™t end here. There is a microcontroller onboard the toy, which interprets the signals and acts accordingly. I am sure that most of us at that time didnвЂ™t try to figure out how it was possible! How could the remote control device in your hand control the car or the aeroplane? Well, of course, the device in your hand sends some data, which is received by the car/aeroplane.

It was pretty fun and fascinating at that time.

As kids, we all must have played with those remote controlled toy cars and airplanes. Ideas can be anything and in any form вЂ“ they could be written/spoken words, in form of media like audio/video, or if you like sci-fi, then it can also in form of telepathy! )Д«ut what does communication between two microcontrollers mean? Its simple! An exchange of data (bits)! There are many protocols for communication (which would be discussed later) but all of them are based on either serial communication or parallel communication. In simple terms, communication is an exchange of ideas between two individuals.

Major Factors Limiting Parallel CommunicationД«efore we move on to serial communication, lets discuss a bit about communication in general.

We will do some practical stuff from next tutorial onwards. This post will cover the basics of serial communication and will be mostly a theoretical topic. Hey folks! Guess what? ItвЂ™s now time for one of the most desired tutorials on maењЋmbedded вЂ“ the Serial Communication series! In these series, we will discuss the basic concepts of serial communication the loopback test, the USART/UART of AVR and then we will proceed towards implementing the SPI and I2C in AVR.