Interfacing DAC Microprocessor and Interfacing by Ravinder Nath Rajotiya - May 4, 2022May 4, 20220 Digital-to-Analog Conversion or simply DAC, is a device that is used to convert a digital (usually binary) code into an analog signal (current, voltage, or electric charge). Digital-to-analog conversion is the primary means by which digital equipment such as computer-based systems are able to translate digital data into real-world signals that are more understandable to or useable by humans, such as music, speech, pictures, video. It also allows digital control of machines, equipment, household appliances. When data is in binary form, the 0's and 1's may be of several forms such as the TTL form where the logic zero may be a value up to 0.8 volts and the 1 may be a voltage from 2 to 5 volts. The
Interfacing LCD Microprocessor and Interfacing by Ravinder Nath Rajotiya - May 4, 2022May 4, 20220 Introduction LCD is the most common display devices used in different dedicated applications be it the instrumentation, medical equipment, panels, robotics etc. It is quite easy to interface it with the microprocessors or microcontrollers. We can directly interface a LCD with microcontrollers, however, for interfacing with microprocessors, we need a peripheral device such as 8255. Here in this post we discuss the basics of LCD, its commands, interfacing using 8255 PPI an final a program to initialize LCD to display some user data on it. PIN Diagram of LCD Pin number Symbol I/O Description 1 Vss xx GND 2 Vcc xx +5V 3 VEE Xx Power Supply to control contrats (use POT) 4 RS I RS=0 to select command Register, to allow user to send command to LCD RS=1 to select data register, allowing user to send data for display 5 R/W I R/W=0 : to Write R/W=1: to
Interfacing Stepper Motor Microprocessor and Interfacing by Ravinder Nath Rajotiya - November 9, 2021November 11, 20210 Interfacing a stepper Motor Definition: These stepper motors are made of permanent magnet rotor with stator field excitation. Unlike the DC motors which move continuously, the stepper motors move in incremental steps. The stepper motor is a type of DC motor with the field placed on the rotor in the form of permanent magnets with two, three or four sets of coils called phases, placed in the stator around the rotor. Common step size of stepper motor is 0.9 to 30 degree. Applications Area: Robotics, printers, object handling, plotters, disk drives etc. Types of Stepper Motors: Stepper motor can be a two phase stepper or a four phase stepper motor. A two phase stepper motor has two stator poles whereas a four phase stepper motor has four
Generating PORT Address for I/O Microprocessor and Interfacing by Ravinder Nath Rajotiya - October 12, 2021October 12, 20210 Generating the Ports for interfacing There are two techniques or methods for interfacing i/o devices, these are: i/o-Mapped I/O- In this method, the i/o device have separate address space and instructions exclusively for inputting or outputting the data from/to the devices. Instructions for reading/writing memory are different than i/o instructions.IN and OUT are used for i/o devices, and MOV is used for memory related operations. memory-mapped I/O- This techniques uses the common address space and instructions for communicating with the memory or the i/o. MOV instruction is used for i/o as well as memory related operations. In the following paragraph we will learn how to create the port addresses for the i/o-mapped i/o technique. We will use some address decoding logic gates for
Serial Communication Microprocessor and Interfacing by Ravinder Nath Rajotiya - May 21, 2021May 21, 20210 Introduction to Serial Communication There are two forms of transmission, these are Serial Communication Parallel Communication Serial Communication Parallel Communication Communication over a single wire Communication over multiple wires, generally over 8 wires to carry a byte of data Slower and cheap Faster but costlier Require Parallel to serial and serial to parallel conversion for transmitting and receiving of data No such conversion is required Baud rate: Baud rate plays an important rle in the communication of serial data. This is the rate at which serial data is transferred. Its unit is bits/sec. Baud rate=1/(time between signal transitions). Example-1 is the signal is changing every 6.3ms, then baud rate= 1/(6.3x10-3)=600bd. Example-2: each character contains a start bit, 7 information bits, a parity bit, one stop bit making a total