Microcontroller Articles - Page 31 of 33

Unsigned binary integers are numbers without any ‘+’or ‘-’ sign. Here all bits representing the number will represent the magnitude part of the number only. No bits will remain reserved for sign bit representation. An unsigned binary integer is a fixed-point system with no fractional digits.Some real life Examples are −Number of tables in a class, The number of a member of a family.Obviously, they are unsigned integers like 10 and 5. These numbers have to be represented in a computer using only binary notation or using bits.Numbers are represented in a computer using a fixed size, like 4, 8, ... Read More

The Intel 8279 is used for keyboard interfacing but it can also be used for multiplexed 7-segment LED display interfacing. To display a character into 7-segment display we have to store 7-segment code in a display RAM location. The display RAM of this chip can store 16 bytes of data.Write to Display RAMTo write to the display RAM one special command is needed to be applied on the 8279 control port. The following pattern is showing the RAM command that is written to the control port of 8279.100AiAAAAThe first three bits are 100. It indicates ‘ Write to Display RAM’command. ... Read More

Here we will see how 8279 Chip can be used to interface a matrix keyboard with 8085 microprocessors. This chip can be used either keyboard/display interfacing mode or as a strobed input port. But generally, it is used as keyboard interfacing.The keyboard interfacing schemes can also be divided into two modes. These modes are Decoded mode of operationEncoded mode of operationDecoded Mode of OperationIn this mode, the matrix keyboard can have only four rows. These four rows can be selected by using SL3-0 select lines. There are eight columns. These can be selected using RL7-0 these eight column lines. So there are ... Read More

In this section, we will see how to connect a stepper motor with Intel 8051 Microcontroller. Before discussing the interfacing techniques, we will see what are the stepper motors and how they work.Stepper MotorStepper motors are used to translate electrical pulses into mechanical movements. In some disk drives, dot matrix printers, and some other different places the stepper motors are used. The main advantage of using the stepper motor is the position control. Stepper motors generally have a permanent magnet shaft (rotor), and it is surrounded by a stator. Normal motor shafts can move freely but the stepper motor shafts move ... Read More

The 8251 chip is Universal Synchronous Asynchronous Receiver Transmitter (USART). It acts as a mediator between the microprocessor and peripheral devices. It converts serial data to parallel form and vice versa. This chip is 28 pin DIP.The pin description of 8251A chipPinDescriptionD0 - D7parallel dataC/DControl register or Data buffer selectRDRead ControlWRWrite controlCSChip SelectCLKclock pulseRESETResetTxCTransmitter ClockTxDtransmitted dataRxCReceiver ClockRxDReceiver DataRxRDYReceiver ReadyTxRDYTransmitter ReadyDSRData Set ReadyDTRData Terminal ReadySYNDET/Synchronous Detect/BRKDETDetectBreakRTSRequest to send DataCTSClear to send DataTxEMPTYTransmitter EmptyVccVcc (5V)GNDGround(0V)Now let us see the functional block diagram of the 8251 chip.There are five different sections in this diagram. These sections are as follows −Read/ Write control logicTransmitter ReceiverData Bus ... Read More

In this section we will see how ADC (Analog to Digital Converter) works with Intel 8085 Microprocessor. The Analog to Digital Conversion is a quantizing process. Here the analog signal is represented by equivalent binary states. The A/D converters can be classified into two groups based on their conversion techniques.In the first technique it compares given analog signal with the initially generated equivalent signal. In this technique, it includes successive approximation, counter and flash type converters. In another technique it determines the changing of analog signals into time or frequency. This process includes integrator-converters and voltage-to-frequency converters. The first process ... Read More

In this section we will see how DAC (Digital to Analog Converter) using Intel 8051 Microcontroller. We will also see the sinewave generation using DAC.The Digital to Analog converter (DAC) is a device, that is widely used for converting digital pulses to analog signals. There are two methods of converting digital signals to analog signals. These two methods are binary weighted method and R/2R ladder method. In this article we will use the MC1408 (DAC0808) Digital to Analog Converter. This chip uses R/2R ladder method. This method can achieve a much higher degree of precision. DACs are judged by its ... Read More

In this section we will see how to write and execute programs for 8051 microcontroller using the Keil Software.Download KeilHere is the download link of Keil. You can download it and install it very easily. We are using C51 version for 8051 devices.https://www.keil.com/download/product/Use Keil to write programs for 8051 MicrocontrollerStart the Keil software. Go to the Project > New Project then choose a location to store your program, and give a name and Save.Now in the next window select the device from different manufacturers. We are selecting Microchip, and then by expanding we are selecting AT89C51 device and click ok.Now ... Read More

There are mainly three different languages with the help of which we can develop computer programs. And they areMachine Level languageAssembly Level Language andHigh-Level LanguageMachine Level LanguageThe computer can understand only the language of Digital Electronics. Digital Electronics deals with the presence and absence of voltages. Within the computer there are two logics can play their role. These logics are −Positive Logic − Here presence of voltage will be denoted by 1 and absence of voltage will be denoted by 0Negative Logic − Here presence of voltage will be denoted by 0 and absence of voltage will be denoted by ... Read More

A Microcontroller is a small and low-cost microcomputer, which is designed to perform the specific tasks of embedded systems like displaying microwave’s information, receiving remote signals etc.The general microcontroller consists of the processor, the memory (RAM, ROM, EPROM), Serial ports, peripherals (timers, counters) etc.Types of MicrocontrollersMicrocontrollers are divided into various categories based on memory, architecture, bits and instruction sets. Following is the list of their typesBit − Based on bit configuration, the microcontroller is further divided into three categories.8-bit microcontroller  − This type of microcontroller is used to execute arithmetic and logical operations like addition, subtraction, multiplication division, etc. For ... Read More