Abstract—

The coming intersection between a growing electrified vehicle fleet and desired growth in renewable electricity generation presents an opportunity for synergistic value. The smart grid is a new concept of electricity supply operation and management that will enable consumers and utilities to better control the electricity usage. This is possible because of the two way electricity and information communication between all nodes in the grid. For Electric Vehicles (EVs) travelling on the road and because of the necessary battery charging times, there is a need for wireless communication between the EVs and the Electric Vehicle Supply Equipment (EVSEs) (charging stations).

What is the need for communication within the charger, battery pack, and motor drive?

Introduction-

Today, charging of EVs generally takes place at home. Just a few charging stations are available in public areas – as part of model studies. Since vehicles are parked frequently, e.g. while shopping or at work, they can be charged during these times. In the future, a broadly based and standardized infrastructure will be built up for this purpose. It has to offer a standardized mechanism for charging the batteries.

International Standardization and its Distribution:

 Widespread establishment of a charging infrastructure can only be properly achieved if all aspects of the charging process are standardized across manufacturers. The connector and cable as well as the charging communication must be standardized for all EVs and charging stations. In Europe, charging communication is described in the framework of ISO 15118. In the USA, this is being done in SAE (Figure 1). In Japan, there is already the CHAdeMO standard and a charging station network of over 250 stations. According to the “National Development Plan for Electromobility” by the German federal government, Germany should become the lead market for electromobility. This plan calls for one million EVs to be on the roads of Germany by 2020.

            

Communication within Charger and Motor drive.

Charging of EVs can cause a severe load of local electrical distribution networks. Today’s electrical grids require some time to react to such load changes. If several charging EVs draw high power simultaneously in one location, e.g. in a parking garage, this could lead to a local grid overload and outage. Until now, no consideration has been given to the total power requirement for charging EVs on the electrical grid. As soon as the driver plugs in the vehicle’s charging cable, charging begins at the maximum possible current, and this adds a certain amount of load to the grid. This might appear to be similar to the model of fueling up at a normal fuel station, where energy is always in stock and is easy to obtain in the form of gasoline. But the situation with electrical energy differs fundamentally. It cannot be stored as simple as gasoline and be drawn from storage. Nonetheless, by introducing an intelligent electrical grid (Smart Grid) and by using intelligent charging, it is possible to avoid overload and grid failure. In a Smart Grid, data is exchanged about power requirements, and the electrical grid can be optimized accordingly. The power needed for a charging operation lies between 3 kW and 20 kW, or even over 100 kW, depending on the available power connection and charging profile. By comparison, a typical citizen in Germany uses an average of 3-5 kWh of daily electrical energy, depending on household size. To operate the grid so that it is more stable, the energy provider needs time to supply the charging energy. One way to obtain this time is to delay the start of the charging operation by several tens of seconds.

 Charging Method for DC or AC Power

 In charging the batteries, two different procedures can be distinguished. First, the battery can be charged with alternating current, which is available in the electrical grid as single-phase or three-phase AC. Nearly, any electrical outlet may be used for charging here. However, the charger must be installed in the vehicle, which means additional weight. In the second variant, the battery is charged with DC electricity. In this case, the charger is located outside of the vehicle, in the charging station, and it generates the DC voltage for charging the batteries. In this case, the weight of the charger does not matter, but costs are higher for such a DC charging station. Since these two charging processes each have their advantages and disadvantages, they are used in parallel.

If the vehicle only has to communicate with the charging station for charging, the choice of transmission medium and protocol would be quite flexible. However, the charging station and vehicle also need to communicate with various servers on the Internet.

          

Therefore, it makes sense to use the conventional protocols of IP-based networks. Since requirements call for just using the cable for the charging current – and no auxiliary lines for communication – communication is implemented directly via the charging cable.

                               

 PLC technology (Power Line Communication) is available for this purpose. In this system, the data stream is modulated onto the power line. This system is more familiar under the names Homeplug AV and IP-over-­powerline in the consumer products field; they offer a simple way to set up private computer networks via a building’s power lines.

In the vehicle’s charge control module, a TCP/IP stack is used for communication. It provides socket communication over IP (Internet Protocol) for TCP (Transmission Control Protocol) or UDP (User Datagram Protocol). Overlaid on this protocol are several applications and protocols such as:

> DNS (Domain Name System) for name resolution.

> TLS (Transport Layer Security) for encrypting the data on the transport level.

> V2GTP (Vehicle To Grid Transport Protocol), a new protocol for connection monitoring and data  transfer.

Furthermore, a module is needed that contains the Smart Charging functionalities from ISO 15118. For this purpose, Vector has developed its own standard module: SCC (Smart Charge Communication.) It establishes the connection to the charging station and exchanges parameters on the charging process over the connection. The module can be adapted to the requirements of specific carmakers and suppliers by its many different configuration options. Currently, data transmission over the Internet is generally still performed using the IPv4 protocol. To circumvent the growing scarcity of addresses on the Internet, ISO requires that vehicles and charging stations support IPv6. Overall, a system is created in the vehicle that is very complex and resource-intensive, but it is also very powerful. Vector already offers an implementation based on the MICROSAR IP stack.

                                                      

It was specially optimized for use in motor vehicles and conforms to the AUTOSAR standard. In addition to the TCP/IP stack, the charger requires a CAN stack to connect to the existing vehicle network. Communication with energy management and the user terminal are implemented via the CAN stack.

                            

Procedure for a Charging Operation

On current EVs, the charging process is simple: the user simply plugs a connector into the charging station, and the charging process starts right away. In Smart Charging per ISO 15118, the charging process is more complex. After plugging in the charging cable, the vehicle first establishes a connection with the charging station via PLC for communication. Then the vehicle obtains an IP address over DHCP, after which the SCC module queries the IP address of the charging station via a broadcast message (ChargePointDiscovery). Now the vehicle establishes a TCP connection and, overlaid on this, a TLS connection over which both the charging station and the vehicle are authenticated by certificates. Data such as service information, rate tables and charging profiles is exchanged and selected over this encrypted connection, and payment modalities are set. Now the cable is physically locked, so that it cannot be pulled during the charging process – as to prevent theft of the electrical power. Finally, the charging station switches the power on, which starts the actual charging process. During this process, the vehicle and charging station regularly exchange status information and electrical meter readings, and the vehicle acknowledges the reception of energy. During charging, the vehicle may be placed in a quiescent state to reduce its own energy consumption. It periodically wakes up from this state to execute a status update. The charging itself continues without stop. When charging is finished, the charging station shuts off the electrical power and unlocks the plug connection. The last acknowledged meter reading is transmitted to the energy provider over the Internet for billing.

Communication within Battery Management system (BMS):

                         

Communication is one of the most important part of the Battery Management System (BMS). BMS is designed to monitor the parameters associated with the battery pack and its individual cells, apply the collected data to eliminate the safety risks and optimize the battery performance. With the help of communication between devices BMS continuously monitors parameters such as temperature, voltage, current in and out of the pack to ensure it is being operated in safe conditions the entire time.

Electric vehicles run on very high voltage lithium-ion battery packs. Lithium-ion batteries have higher energy density (100-265 Wh/kg) than other battery chemistries. These batteries come with the risk of catching fire under unusual circumstances. It is imperative to operate the EV batteries in a pre-defined safe limits to ensure the safety of the user as well as the vehicle.

With the help of communication BMS is responsible for thermal management of the battery and monitors its temperature continuously. If required, BMS can adjust cooling and trigger other safety mechanisms to seize operations and minimize risk. For e.g. Hyundai Kona Electric, if overheating of the battery pack is detected by the BMS, the vehicle’s power is automatically limited and the car is put in full-safe mode.

Overcharging of lithium-ion cells can also lead to thermal runaway and potentially an explosion. BMS continuously monitors the voltage of the pack as well as individual battery cells and controls the supply of the current to avoid overcharging.  BMS can enforce the limits of the maximum charge or discharge according to temperature.

Through communication BMS is responsible for optimising the performance of the battery pack. Lithium-ion batteries perform best when their State of Charge (SOC) is maintained between minimum and maximum charge limits defined in the battery profile. Overcharging as well as deep discharging degrades the capacity of the battery, thereby shortening its life. At the time of charging BMS determines how much current can safely go in & communicates the same to the EVSE (Electric Vehicle Supply Equipment or the charger). During discharge of the battery, BMS would communicate to the motor controller to avoid cell voltages reaching too low. Vehicles can show corresponding alert to the user to charge the battery pack. The BMS also controls the recharging of the battery pack by generated energy through regenerative braking.

With the help of communication technology BMS uses the collected data points (temperature, voltage, current) to estimate the State of Charge (SOC) & State of Health (SOH) of the battery pack. With the help of communication techniques BMS is responsible for communicating with other ECUs in the vehicle. It relays the necessary data about the battery parameters to the motor controller to ensure the smooth running of the vehicle. In case of AC charging the BMS communicates with the on board charger to monitor and control the charging of the battery pack. For DC charging the communication link is directly established between the EVSE and the BMS. BMS communicates the required output voltage and current levels to the EVSE. & sends instructions to start and stop the charging process.

 2. 1 Write a pseudo code for displaying speed on the digital dashboard as per below conditions. 

        Update displayed speed every second, Turn on high efficiency indicator between 50 to 60 kmph, Turn on safe drive indicator above 80 kmph.  

Pseudocode is an informal way of programming description that does not require any strict programming language syntax or underlying technology considerations. It is used for creating an outline or a rough draft of a program and summarizes a program's flow. 

A program flowchart is the simplest way to figure out the bugs in a program before carrying out, saving a lot of time, labor, and money.

A flowchart is a graphical representation of various logical steps of a program. These expressions use several shapes, including the geometric ones, to show the step-by-step process with arrows while establishing a data flow. There are 21 different types of flowcharts, and a programming flowchart is one of them.

The program flowchart is a data flow that shows the data flow while writing a program or algorithm. It allows the user to explain the process quickly as they collaborate with others. These programming flowcharts also analyze the logic behind the program to process the code of the programming. The programming flowcharts can serve in different ways. For example, they can analyze the codes, visualize and work on them. They can also help figure out the application's structure to realize how a user navigates in a tool.

The programming flowcharts improve the condition and efficiency of work. The tool has four basic symbols that have code written on them for programming. They give commands like START, PROCESS, DECISION, and END, and these symbols are the crucial part of the programming flowcharts. They help in forming a relationship between various elements to describe the data flow.

Flowchart Symbols:

For creating a programming flowchart, the user needs programming flowchart examples. The flowcharts use diagrams to express an algorithm, and hence flow charts are very helpful in creating and analyzing the details of a program. The flow charts use some symbols that can explain the logic of programming connected with the flowchart elements. Here are some widely-used programming flowchart symbols.

SYMBOL	PURPOSE	DESCRIPTION
	Terminal (START / STOP)	The terminal symbols present in every programming flowchart as the process starts with a "START" command, and a "STOP" command shows the end of the whole process on the flowchart. the example also has both the START and END symbols represented by a rectangular sign with curved edges to signify the beginning and end of a programming flowchart procedure.
	Input / Output	Input/Output: The commands of Input and Output are more crucial. To get the Logical flow to go through the processing, the user needs to give Inputs. The System Reads the Input to give an output. The Symbol for input and output are Parallelograms.
	Processing	For a Process to complete successfully. the method must include the function of processing. The processing part occurs between Input and Output. The Rectangle shapes represent the processing work.
	Decision	When there is need to decide between True or False this function get used. The Diamond-Shaped symbols are useful when the function is taking a series of decision to get the results
	On-Page Connector	When there is a need to connect different flowlines, On-page connectors are present at the junction.
	Off-Page Connector	The Off-Page Connectors connect different flowlines when they are present on separate pages.
	Predefined Process/Function	When a group of some statements performs a predefined work, Its representation occurs with this symbol.
	Flow line	It Indicate the direction of flow of Instruction.

1. Write a pseudo code for displaying speed on the digital dashboard as per below conditions. 

        Update displayed speed every second, Turn on high efficiency indicator between 50 to 60 kmph, Turn on safe drive indicator above 80 kmph.  

 Application link: https://www.diagrameditor.com/webapp/?splash=0&ui=atlas&tr=0&gh=0&gl=0&gapi=0&od=0&db=0&lang=en

 

3. a.) What are the factors affecting the selection of microprocessors / microcontrollers?

Just about any new electronic product requires some sort of “brains”. The question though is what type of brains does your product really need?

There are two choices: a Microcontroller unit (MCU) or a Microprocessor unit (MPU). As the name implies a microcontroller excels at “controlling” other hardware components (sensors, switches, motors, etc.), whereas a microprocessor excels at “processing” large amounts of data very quickly. That being said, microcontrollers are able to also process data, and microprocessors are able to control other devices. But each excels in one area.Selecting the correct option is one of the most important first steps to developing your new electronic product.

Microprocessors on the other hand are general purpose computing devices which incorporate all the functions of the central processing unit on a chip but do not include peripherals like memory and input and output pins like the microcontroller.

          

A microcontroller contains a Central Processing Unit (CPU), memory, and peripherals all embedded in a single chip. A MCU is a highly integrated computer chip designed to mostly stand on its own without the need for external support chips.The central processing unit inside of a microcontroller is essentially the same as a microprocessor. So fundamentally a microprocessor  on the other hand are general purpose computing devices which incorporate all the functions of the central processing unit on a chip but do not include peripherals like memory and input and output pins like the microcontroller. A MCU includes a CPU plus memory and peripherals so:

Microprocessor (MPU) = CPU

Microcontroller (MCU) = CPU + Memory + Peripherals

The first rule to remember is that whenever it is possible, use a microcontroller! Only consider a microprocessor if it is absolutely required. I estimate that probably 90% of the product ideas that are presented to me can be best served with a microcontroller. Only about 10% of products are really complex enough to warrant a faster microprocessor. I recommend approaching this decision by assuming your product can use a microcontroller, until you can prove otherwise. Although, there will be some applications that are best served with both a microcontroller and a microprocessor. For instance, an advanced robot with artificial intelligence, facial recognition, speech processing, and a complex graphical user interface will require a fast microprocessor. On the other hand, the robot also needs to incorporate sensors and motors. Those functions are best controlled by a microcontroller separate from the core microprocessor. The microcontroller will act as a subsystem that interfaces with the microprocessor.

                                                

                                            MicroProcessor  (MPU)                                                                                          MicroController (MCU) 

 Factors to Consider when Selecting a MPU or MCU 

Before making any decision on the direction to go as regards the processing device to use for the design of an embedded product, it is important to develop the design specifications. Developing the design specifications provide an avenue for device pre-design which helps identify in details, the problem to be solved, how it is to be solved, highlights the components to be used and much more. This helps the designer make informed general decisions about the project and helps determine which direction to travel for the processing unit.

                    

 Some of the factors in the design specification that needs to be considered before choosing between a microcontroller and a microprocessor are described below.

1. Processing Power 

Processing power is one of the main (if not the main) things to consider when selecting between a microcontroller and a microprocessor. It’s one of the main factors that tilt user to microprocessors. It is measured in DMIPS (Dhrystone Million of Instructions Per Seconds) and represents the number of instructions a microcontroller or microprocessor can process in a second. It is essentially an indication of how fast a device can complete a task assigned to it while determining the exact computational power your design requires can be a very difficult task, an educated guess can be made, by examining the task(s), the device is being created to perform and what the computational requirements of those tasks might be.  For instance the development of a device that requires the use of a full operating system either embedded Linux, windows CE or any of the other OS would require a processing power as high as 500 DMIPS, sounding like a processor? Yes. To add to it, running an operating system on a device will require a memory management unit (MMU) which will increase the required processing power. Device applications that involve a lot of arithmetic also require very high DMIPS values and the more the math’s/numeric computations the device is to perform, the more the design requirements tilt towards the use of a microprocessor due to the processing power required.

One other main implication of processing power that affects the choice between microprocessors and microcontrollers is the complexity or simplicity of things like User interfaces. Asides some of the core functions mentioned above, it is important to reserve some processing power for communications and other peripherals.

 2. Interfaces 

The interface to be used to connect different elements of the product is one of the factors to be considered before choosing between a microcontroller and a microprocessor. It is important to ensure the processing unit to be used has the interfaces required by the other components.

From connectivity and communications stand point for instance, Most microcontrollers and Microprocessors possess the interfaces required to connect to communication devices but when high speed communication peripherals like the super speed USB 3.0 interface, multiple 10/100 Ethernet ports or Gigabit Ethernet port are required, things tilt in the direction of the Microprocessor as the interface required to support these are generally only found on them because they are more capable of handling and processing the large amounts of data and the speed at which those data are transferred.

The Impact of the protocols used for these interfaces on the amount of memory required for the firmware should be confirmed as they tend to increase memory requirements. It’s a general rule of thumb that a microprocessor-based design, be adopted for applications that require high-speed connectivity with large amount of data being exchanged especially when the system involves the use of an operating system.

 3. Memory 

These two data processing devices handle memory and data storage differently. Microcontrollers for instance come with embedded, fixed memory devices while microprocessors come with interfaces to which memory devices can be connected. Two major implications of this are;

 Cost 

The microcontroller becomes a cheaper solution, since it does not require the use of an additional memory device while the microprocessor becomes an expensive solution to be adopted due to these additional requirements.

 Limited Memory 

The fixed memory on the microcontroller makes the amount of data which can be stored on it limited. This is a situation not applicable to processors since they are usually connected to external memory devices. A good example of when this limitation can be a problem is when developing firmware for the device. Adding Additional kilobytes to the code size may require a change in the microcontroller to be used but if the design were based on a processor, we will only need to change the memory device. Thus Microprocessors offer more flexibility with memory.

There are several other factors based on the memory to be considered, one of them is the start-up (boot) time. The Microprocessors for instance stores the firmware on an external memory (Usually an external NAND or Serial Flash memory) and on boot, the firmware is loaded into the DRAM of the processor.  While this takes place within a couple of seconds, it might not be Ideal for certain applications. The microcontroller on the other takes less time.

For general speed considerations, the MCU usually wins due to its ability to address the most time critical applications because of the processor core used in them, the fact that the memory is embedded and the firmware used with them is always either an RTOS or bare metal C.

 4. Power 

A final point to consider is power consumption. While Microprocessors have low power modes, these modes are not as many as the ones available on a typical MCU and with the external components required by a microprocessor based design, it is slightly more complex to achieve low power modes. Asides from the low power modes, the actual amount of power consumed by an MCU is a whole lot lower than what a microprocessor consumes, because the larger the processing capability, the more the amount of power required to keep the processor up and running.

Microcontrollers therefore tend to find applications where ultra-low power processing units are required such as remote controls, consumer electronics and several smart devices where the design emphasis is on the longevity of battery life. They are also used where a highly deterministic behavior is needed.

Microprocessors on the other hand are ideal for industrial and consumer applications that require an operating system, are computation intensive and require high-speed connectivity or a user interface with lots of media information.

 

3.  b.) Explain the architecture of an 8-bit microcontroller(8051 or any other type can be considered). List the applications for the same.

8051 Microcontroller Architecture with Applications

The 8051 Microcontroller was designed in the 1980s by Intel. Its foundation was on Harvard Architecture and was developed principally for bringing into play Embedded Systems. At first, it was created using NMOS technology but as NMOS technology needs more power to function therefore Intel re-intended Microcontroller 8051 employing CMOS technology and a new edition came into existence with a letter ‘C’ in the title name, for illustration: 80C51. These most modern Microcontrollers need a fewer amount of power to function in comparison to their forerunners. There are many applications with an 8051 microcontroller. So, 8051 Microcontroller Projects have great significance in Engineering final year.

What is an 8051 Microcontroller?

The microcontroller like 8051 was designed in the year 1981 by Intel. The microcontroller is one kind of integrated circuit that includes 40-pins with dual inline package or DIP, RAM-128 bytes, ROM-4kb & 16-bit timers–2. Based on the requirement, it includes addressable & programmable 4 – parallel 8-bit ports. In the 8051 microcontroller architecture, the system bus plays a key role to connect all the devices to the central processing unit. This bus includes a data bus- an 8-bit, an address bus-16-bit & bus control signals. Other devices can also be interfaced throughout the system bus like ports, memory, interrupt control, serial interface, the CPU, timers.

There are two buses in 8051 Microcontroller one for the program and another for data. As a result, it has two storage rooms for both programs and data of 64K by 8 sizes. The microcontroller comprises of 8-bit accumulator & an 8-bit processing unit. It also consists of 8 bit B register as majorly functioning blocks and 8051 microcontroller programming is done with embedded C language using Keil software. It also has several other 8 bit and 16-bit registers.

For internal functioning & processing Microcontroller, 8051 comes with integrated built-in RAM. This is prime memory and is employed for storing temporary data. It is an unpredictable memory i.e. its data can get be lost when the power supply to the Microcontroller switched OFF.  This microcontroller is very simple to use, affordable less computing power, simple architecture & instruction set.

Features

                                                        8051 Microcontroller Pin Diagram

                                         

The main features of the 8051 microcontroller architecture include the following.

• 8-bit CPU through two Registers A & B.
• 8K Bytes – Internal ROM and it is a flash memory that supports while programming the system.
• 256 Bytes – Internal RAM where the first RAM with 128 Bytes from 00H to 7FH is once more separated into four banks through 8 registers in every bank, addressable registers -16 bit & general-purpose registers – 80.
• The remaining 128 bytes of the RAM from 80H to FFH include Special Function Registers (SFRs). These registers control various peripherals such as Serial Port, Timers, all I/O Ports, etc.
• Interrupts like External-2 & Internal-3
• Oscillator & CLK Circuit.
• Control Registers like PCON, SCON, TMOD, TCON, IE, and IP.
• 16-bit Timers or Counters -2 like T0 & T1.
• Program Counter – 16 bit & DPRT (Data Pointer).
• I/O Pins – 32 which are arranged like four ports such as P0, P1, P2 & P3.
• Stack Pointer (SP) – 8bit & PSW (Processor Status Word).
• Serial Data Tx & Rx for Full-Duplex Operation

8051 Microcontroller Architecture

The 8051 microcontroller architecture is shown below. Let’s have a closer look at the features of the 8051 microcontroller design:

                   

CPU (Central Processor Unit):

As you may be familiar that the Central Processor Unit or CPU is the mind of any processing machine. It scrutinizes and manages all processes that are carried out in the Microcontroller. The user has no power over the functioning of the CPU. It interprets the program printed in storage space (ROM) and carries out all of them and does the projected duty. CPU manages different types of registers in the 8051 microcontrollers.

Interrupts:

As the heading put forward, Interrupt is a subroutine call that reads the Microcontroller’s key function or job and helps it to perform some other program which is extra important then. The characteristic of 8051 Interrupt is extremely constructive as it aids in emergency cases. Interrupts provide us a method to postpone or delay the current process, carry out a sub-routine task and then all over again restart standard program implementation.

The Micro-controller 8051 can be assembled in such a manner that it momentarily stops or break the core program at the happening of the interrupt. When the sub-routine task is finished then the implementation of the core program initiates automatically as usual. There are 5 interrupt supplies in the 8051 Microcontroller, two out of five are peripheral interrupts, two are timer interrupts and one is serial port interrupt.

Memory:

The micro-controller needs a program that is a set of commands. This program enlightens the Microcontroller to perform precise tasks. These programs need a storage space on which they can be accumulated and interpret by the Microcontroller to act upon any specific process. The memory which is brought into play to accumulate the program of the Microcontroller is recognized as Program memory or code memory. In common language, it’s also known as Read-Only Memory or ROM.

The microcontroller also needs memory to amass data or operands for the short term. The storage space which is employed to momentarily data storage for functioning is acknowledged as Data Memory and we employ Random Access Memory or RAM for this principle reason. Microcontroller 8051 contains code memory or program memory 4K so which has 4KB Rom and it also comprises data memory (RAM) of 128 bytes.

Bus:

Fundamentally Bus is a group of wires which function as a communication canal or means for the transfer of Data. These buses comprise 8, 16, or more cables. As a result, a bus can bear 8 bits, 16 bits altogether. There are two types of buses:

1. Address Bus:Microcontroller 8051 consists of a 16-bit address bus. It is brought into play to address memory positions. It is also utilized to transmit the address from the Central Processing Unit to Memory.
2. Data Bus:Microcontroller 8051 comprise of 8 bits data bus. It is employed to cart data.

Oscillator:

As we all make out the Microcontroller is a digital circuit piece of equipment, thus it needs a timer for its function. For this function, Microcontroller 8051 consists of an on-chip oscillator that toils as a time source for the CPU (Central Processing Unit). As the productivity thumps of the oscillator are steady as a result, it facilitates harmonized employment of all pieces of the 8051 Microcontroller. Input/output Port: As we are acquainted with that Microcontroller is employed in embedded systems to manage the functions of devices.

Thus to gather it to other machinery, gadgets or peripherals we need I/O (input/output) interfacing ports in Micro-controller. For this function Micro-controller 8051 consists of 4 input/output ports to unite it to other peripherals. Timers/Counters: Micro-controller 8051 is incorporated with two 16 bit counters & timers. The counters are separated into 8-bit registers. The timers are utilized for measuring the intervals, to find out pulse width, etc.

Types of Interrupts 

The interrupts of the 8051 microcontrollers have the following sources

• TF0 (Timer 0 Overflow Interrupt)
• TF1 (Timer 1 Overflow Interrupt)
• INT0 (External Hardware Interrupt)
• INT1 (External Hardware Interrupt)
• RI/TI (Serial Communication Interrupt)

Memory 

The memories of the 8051 microcontroller architecture include a program memory and data memory.

• The instructions of the CPU are stored in the Program Memory. It is usually implemented as Read-Only Memory or ROM, where the Program written into it will be retained even when the power is down or the system is reset.
• Data Memory in a Microcontroller is responsible for storing values of variables, temporary data, intermediate results, and other data for the proper operation of the program.

Timer and Control Unit 

The main function of a timer is to make a delay otherwise time gap among two events. This microcontroller includes two timers where each timer is 16-bit where the system can generate two delays concurrently to produce the suitable delay. Generally, every microcontroller uses hardware delays where a physical device can be used through the processor to generate the particular delay which is called a timer.

The delay can be generated through the timer based on the requirement of the processor & transmits the signal to the processor whenever the particular delay gets generated.

By using this processor, we can also produce a delay based on the requirement of the system. However, this will guide to remain the processor active all the time because it will not perform any other task in that specific period. As a result, the existence of a timer within the microcontroller permits the processor to be free for performing other operations.

The microcontroller also includes a program counter, data pointer, stack & stack pointer, instruction registers including latches, temporary registers & buffers for the I/O ports.

Registers 

Registers in microcontrollers are mainly used to store data and short-term instructions which are mainly used to process addresses to fetch data. This microcontroller includes 8-bit registers which have 8-bit start from D0 to D7. Here, D0 to D7 is LSB (least significant bit) and D7 is the most significant bit (MSB).

To make the data process better than 8-bit, then it must be separated into eight different bit parts. It includes several registers however general-purpose type registers are frequently available to programmers. There are classified into two types like General purpose & Special purpose. So, most of the general-purpose registers are listed below.

• An accumulator is mainly used to execute arithmetic & logic instructions.
• Registers like B, R0 toR7 are used for storing instruction addresses & data.
• Data Pointers or DPTR is used to allow & process data in dissimilar addressing modes. This register includes DPH (high byte) & a DPL (low byte) which is mainly used to hold a 16-bit address. So, it can be used as a base register within not direct jumps, lookup table instructions & external data transfer.
• Program counter or PC is a 16-bit register used to store the next instruction’s address to be performed
• These registers are 8-bits other than program counter & data pointer registers.

Data Types 

This microcontroller includes simply one 8 bit data type where the size of each register is 8-bit. If the data is better than 8-bit, then is the programmer accountable to separate data into 8-bit parts before processing. For assemblers, the most widely used data directive is the DB directive in assembly language.

PSW Register 

The term PSW stands for Program status word and it is one kind of register in the microcontroller. It is also called a flag register, used to demonstrate the position of arithmetic logic instructions such as zero carry bit, carry bit, etc. PSW or flag register is an 8-bit register where 6-bits are used. This register includes 8-flags where these flags are known as conditional flags. These flags will perform instruction simply if the condition is satisfied.

These conditional flags are overflow, parity, auxiliary carry & carry. The Program status word registers bit numbers like 3 & 4 are used to alter the bank registers whereas 1 & 5 are not used but they can be used by the programmer for executing a specific task.

Register Banks 

For stacks & register banks, Ram with 32 Bytes is used and these are separated in four types of banks. So, every back includes 8-registers which range from R0 to R7. Here, R0 & R7 denotes the locations of RAM like zero location and seventh location. The second bank register begins from location 8 & ends 05H. The third bank register begins from 10H & completed at the 17H location. The final bank can be placed among the 18H-1FH.

Stack 

The part of RAM like Stack is mainly used through the processor for data storage otherwise address momentarily. In a microprocessor, it is a very significant part because there are extremely restricted numbers of registers for storing addresses and data.

In the 8051 microcontrollers, the stack is 8-bit wide and it can hold data from 00 – FFH. The stack pointer can be used through the CPU to allow the stack. This microcontroller includes an 8-bit stack pointer that means it can allow values from 00H to FFH. Once it is activated, then the stack pointer includes the 07 value.

Organization of Memory 

The microcontroller has complex memory organization and it includes a separate address bus that is used for program memory, external RAM & data memory. It depends on Harvard architecture that is developed through Harvard in the year 1944.

Addressing Modes 

Microprocessor gets data in different methods. Generally, the data stored within memory, register & can be used from instant value. So, these different methods for accessing data are known as addressing modes. Different types of microcontrollers include different addressing modes which depend on the plan of manufacturers. The addressing modes of this microcontroller include the following.

• Register
• Register indirect
• Immediate
• Indexed
• Direct

Applications of 8051 Microcontroller Architecture

The microcontroller 8051 applications include a large number of machines, principally because it is simple to incorporate in a project or to assemble a machine around it. The following are the key spots of the spotlight:

1. Energy Management:Competent measuring device systems aid in calculating energy consumption in domestic and industrialized applications. These meter systems are prepared competent by integrating microcontrollers.
2. Touch screens:A high degree of microcontroller suppliers integrate touch sensing abilities in their designs. Transportable devices such as media players, gaming devices & cell phones are some illustrations of micro-controller integrated with touch sensing screens.
3. Automobiles:The microcontroller 8051 discovers broad recognition in supplying automobile solutions. They are extensively utilized in hybrid motor vehicles to control engine variations. Also, works such as cruise power and anti-brake mechanism have created it more capable with the amalgamation of micro-controllers.
4. Medical Devices:Handy medicinal gadgets such as glucose & blood pressure monitors bring into play micro-controllers, to put on view the measurements, as a result, offering higher dependability in giving correct medical results.
5. Medical Devices:Handy medicinal gadgets such as glucose & blood pressure monitors bring into play micro-controllers, to put on view the measurements, as a result, offering higher dependability in giving correct medical results.

3  c.) Explain the different types of transmission(serial communication) modes with the help of real-time examples.

Transmission modes

• The way in which data is transmitted from one device to another device is known as transmission mode.
• The transmission mode is also known as the communication mode.
• Each communication channel has a direction associated with it, and transmission media provide the direction. Therefore, the transmission mode is also known as a directional mode.
• The transmission mode is defined in the physical layer.

The Transmission mode is divided into three categories:

                    

  Simplex mode  

        

• In Simplex mode, the communication is unidirectional, i.e., the data flow in one direction.
• A device can only send the data but cannot receive it or it can receive the data but cannot send the data.
• This transmission mode is not very popular as mainly communications require the two-way exchange of data. The simplex mode is used in the business field as in sales that do not require any corresponding reply.
• The radio station is a simplex channel as it transmits the signal to the listeners but never allows them to transmit back.
• Keyboard and Monitor are the examples of the simplex mode as a keyboard can only accept the data from the user and monitor can only be used to display the data on the screen.
• The main advantage of the simplex mode is that the full capacity of the communication channel can be utilized during transmission.

Advantage of Simplex mode:

• In simplex mode, the station can utilize the entire bandwidth of the communication channel, so that more data can be transmitted at a time.

Disadvantage of Simplex mode:

• Communication is unidirectional, so it has no inter-communication between devices.

 Half-Duplex mode 

         

• In a Half-duplex channel, direction can be reversed, i.e., the station can transmit and receive the data as well.
• Messages flow in both the directions, but not at the same time.
• The entire bandwidth of the communication channel is utilized in one direction at a time.
• In half-duplex mode, it is possible to perform the error detection, and if any error occurs, then the receiver requests the sender to retransmit the data.
• A Walkie-talkie is an example of the Half-duplex mode. In Walkie-talkie, one party speaks, and another party listens. After a pause, the other speaks and first party listens. Speaking simultaneously will create the distorted sound which cannot be understood.

Advantage of Half-duplex mode:

• In half-duplex mode, both the devices can send and receive the data and also can utilize the entire bandwidth of the communication channel during the transmission of data.

Disadvantage of Half-Duplex mode:

• In half-duplex mode, when one device is sending the data, then another has to wait, this causes the delay in sending the data at the right time.

 Full-duplex mode 

        

• In Full duplex mode, the communication is bi-directional, i.e., the data flow in both the directions.
• Both the stations can send and receive the message simultaneously.
• Full-duplex mode has two simplex channels. One channel has traffic moving in one direction, and another channel has traffic flowing in the opposite direction.
• The Full-duplex mode is the fastest mode of communication between devices.
• The most common example of the full-duplex mode is a telephone network. When two people are communicating with each other by a telephone line, both can talk and listen at the same time.

Advantage of Full-duplex mode:

• Both the stations can send and receive the data at the same time.

Disadvantage of Full-duplex mode:

• If there is no dedicated path exists between the devices, then the capacity of the communication channel is divided into two parts.

 COMPARISON: 

Basis for Comparison	Simplex	Half Duplex	Full Duplex
Direction of Communication	Unidirectional	Two-directional, one at a time	Two-directional, simultaneously
Send / Receive	Sender can only send data	Sender can send and receive data, but one a time	Sender can send and receive data simultaneously
Performance	Worst performing mode of     transmission	Better than Simplex	Best performing mode of       transmission
Example	Keyboard and monitor	Walkie-talkie	Telephone

 

Conclusion:-

1. BSM is very much important for the Vehicle because it is like the blood which is useful as per our body same like communication is essential.
2. using the pseudocode we can write it in different languages
3. Several other factors exist and serve as determinants for choosing between these two platforms and all fall underperformance, capability and budget but the overall selection becomes easier when a proper systems pre-design is in place and the requirements clearly stated. Microcontrollers are mostly used in solutions with a very tight BOM budget and with stringent power requirements while Microprocessors are used in applications with huge computation and performance requirements.
4. we also learned about different data Transmission Modes based on the direction of exchange, synchronization between the transmitter and receiver, and the number of bits sent simultaneously in a  communication network.

Reference:

1. https://www.ijert.org/battery-management-system-integrated-with-can-bus-safety-control-environment-for-electric-vehicle
2. https://www.intechopen.com/chapters/18669
3. https://www.youtube.com/watch?v=2mrldnWz__U&list=PLiZaRKKs2OshF56LirxiozIoD6Fv2TVtu
4. https://www.youtube.com/watch?v=4eJRPoDLxVQ&list=PLiZaRKKs2OshF56LirxiozIoD6Fv2TVtu&index=2
5. https://www.totalphase.com/blog/2019/12/microcontroller-vs-microprocessor-what-are-the-differences/
6. https://rawabiholding.com/wp-content/uploads/2019/04/WhitePaper_-_Microcontroller_and_Microprocssor_selection_Guide_v1.0_by_Fawzi_Mudawwar.pdf
7. https://www.watelectronics.com/8051-microcontroller-architecture/
8. https://www.tutorialspoint.com/microprocessor/microcontrollers_8051_architecture.htm
9. https://www.tutorialspoint.com/embedded_systems/es_microcontroller.htm
10. https://instrumentationtools.com/serial-communication-data-transmission-modes/