Microcontroller interfacing circuits pdf 44p currently this section contains no detailed description for the page, will update this page soon. It includes an example circuit and software for a pic18f442. Nov 02, 2012 in todays tutorial, i am gonna show you relay interfacing with microcontroller using uln2003a. We can drive two dc motors with one l293d, in this example we are using only the first pair of drivers to drive one dc motor. May 21, 2016 automatic street light control using 8051 micro controller,keil ide and proteus simulation duration. As it can be seen from the above circuit diagram, a uln2003 is connected between the microcontroller and relays in order to drive multiple relays. In this tutorial we are going to interface an optocoupler with atmega8 microcontroller. For detailed working of relay please visit this page. This simple device isolates the sensitive electronics from robust electronics like motors, yet keeping the load in control over the source. Following things should be taken into account while designing the. Interfacing the max1169 adc to a pic microcontroller by. Ssrs make interfacing with ac voltage really, really simple. In this project report description of inputoutput interfacing of microcontroller and the program, which is.
Programming and interfacing the 8051 microcontroller in c and. Dc motors need much more current than a microcontroller can provide, so it needs separate drivers. Relays are devices which allow low power circuits to switch a relatively high current andor voltage onoff. Relay interfacing with microcontroller 8051 microcontroller. To interface relay with microcontroller we need a driver circuit to drive the power to relay. It should not be directly connected to a pic microcontroller.
The agsno2 contacts can handle higher inrush currents than agni. If you want to know more about relay driver circuit uln2003, relay working and relay interfacing with arduino check these articles. A relay is a switch which is used to switch high voltage or current using low power circuits. Interfacing hcsr04 ultrasonic rangefinder with pic 16f877a microcontroller dht11 humidity sensor interface with pic16f877a p10 rg led display interface with stm32f030f4 32bit mcu. Interfacing is one of the important concepts in microcontroller 8051 because the microcontroller is a cpu that can perform some operation on a data and gives the output. Interfacing a relay to a pic microcontroller if possible, the relay should be powered by a separate power supply to enable a connection of relays requiring a different voltage like for example a 12v relay which is different form the 5v supplied to the microcontroller. Rj45 ethernet controller ic microcontrollerwith spi would this method interfere with the serial communication port as spi would require rxd and txd pins of microcontroller which are used to connect with pins of line driver totally confused rj45 microcontroller i doubt it. Oct 09, 2012 interfacing methods of microcontroller 1. Microcontroller components, a typical microcontroller application, motorola 68hc12 microcontroller, 68hc12 programming model, 68hc12 data types, auto prepost decrementincrement, indexed addressing, 68hc12 move instructions, hc12 logic instructions, multiply and.
Peripherals interfacing to the microcontroller 8051 in. In this project we will interface a relay with pic microcontroller pic16f877a and control a 220v ac lamp using the relay. Here is a simple microcontrollerrelay interface circuit. Example programs are written in the c programming language. Have you ever wondered how your pc and phones keep track of time even when the device is turned off. Nov 23, 2014 interfacing hcsr04 ultrasonic rangefinder with pic 16f877a microcontroller dht11 humidity sensor interface with pic16f877a p10 rg led display interface with stm32f030f4 32bit mcu. Now we are gonna have a look at how to interface this relay with microcontroller and then use it in your project. So we connect output from our microcontroller pin to the base of transistor. These are monolithic ic s consists of high voltage high current darlington transistor arrays. The pic 16f877a pic microcontroller is one of the most popular general purpose. Mar 02, 20 interfacing relay with pic microcontroller using uln2003.
So, in order to detect the key pressed from the keypad, the row lines have to be made low one by one and to read the. Programming with pic microcontroller research design lab. In this tutorial, we will learn about the interfacing of the relay relay connection with microcontroller and learn how to control a device using the relay. Different dc motors need different voltages and operating high voltage motor from a low voltage controller is not a feasible option. Development of programmable relay switch using microcontroller. If you want to use more relays, using transistors will be difficult. There are 2 output channels that each correspond to an input. Realtime operating systems for arm cortexm microcontrollers is an advanced. How to turn on and turn off relay with pic microcontroller by using digital output ports of pic16f877a microcontroller. The success of the intel 8051 spawned a number of clones which are collectively referred to as the mcs51 family of microcontrollers, which includes chips from vendors such as atmel, philips, infineon, and texas instruments. Internally relay consist of a coil of wire wrapped soft iron core. Basic code examples are provided for users of the basic. It is therefore connected to ouput pins of the microcontroller and used to turn onoff highpower devices such as motors, transformers, heaters, bulbs, antenna systems etc.
This section will help to enable those with limited electronics experience to successfully complete these interfacing tasks. The 8051 family with its many enhanced members enjoys the largest market share, estimated to be about 4 0%, among the various microcontroller architectures. Relay is a mechanical device to control high voltage, high current appliances on or off from lower voltage levels. Whenever 8051 microcontroller is turned on initially the controller is in reset state and all the controller pins are high which would result in turning on the relay every time power is turned on or if there is a power fluctuation. The input is taken from the microcontroller pins and the output corresponding to each input is given to the 5. Analog to digital converters sampling rate mhz sampling resolution bits interface type parallel or serial reference voltage volt input range unipolar or bipolar. Martin bates has drawn upon 20 years of experience of teaching microprocessor systems to produce a book containing an excellent balance of theory and practice with numerous working examples throughout. However to perform the operation we need an input device to enter the data and in turn output device displays the results of the operation. Each input is connected to the triggering coil of the respective relay.
From mechanical to solid state relays, there are various type of relays are available in. Interfacing lcd module with microcontroller embedjournal. To facilitate multiple features with simple circuits, microcontroller is interfaced with devices such as adc, keypad, lcd. I have not been able to find a good reference to suggest. Atmega8 microcontroller, power supply 5v, avrisp programmer, 4n25 optocoupler, 1k. Well there is a real time clock rtc that is kept powered even is the device is turned off. Interfacing relay to microcontroller dna technology.
Microcontroller is a programmable digital processor with necessaryperipherals. Microcontroller interfacing to relays using uln2003, in this article, you will learn how to interface microcontroller to relays using uln2003 relay driver circuit. A microcontroller is a computer on a chip used to control electronic devices. Relay provides isolation between two voltage levels and it is generally use to control ac appliances. To understand how microcontroller works as a multifunctional relay it is necessary to know about microcontroller working, functions and its applications. Applications of interfacing devices with microcontroller.
Wireless communication using rf module and interfacing with. Microcontroller interfacing to relays using uln2003 relay. This book provides a comprehensive look into the architecture, programming, and interfacing of the microcontroller. Interfacing methods of microcontroller linkedin slideshare. The potentiometer is used to adjust the reference voltage for the microcontrollers onchip analog comparator. Relay interfacing with microcontroller using uln2003a. Interfacing the max1169 adc to a pic microcontroller. In this tutorial im connecting one relay in port b. The circuit diagram for optocoupler interfacing with avr microcontroller is shown in figure. A pic microcontroller is a single integrated circuit small enough to fit in the palm of a hand. Before interfacing, every one should know about the relay driver which is used to interface the relay to microcontroller.
The rf modules working with a certain frequency range transfer and receive the data with analog form, but for a microcontroller working with the binary data 0 or 1s, the rf transmitter is interfaced to such microcontroller with the help of an encoder, and the rf receiver is connected to the microcontroller with help of a decoder. This may also damage the device connected to relay so as to avoid. In this project we will interface a relay with pic microcontroller pic16f877a. Interfacing of relay with microcontroller aticleworld. Picaxe microcontroller interfacing circuit revolution education.
It is activated by energizing a coil wounded on a soft iron core. Interfacing pic microcontrollers, 2nd edition is a great introductory text for those starting out in this field and as a source reference for more experienced engineers. Its a simple wirewrapped board with all throughhole components except the adc. Programming and interfacing the 8051 microcontroller in c. A pic microcontroller is a single integrated circuit pic microcontrollers can be used as the brain.
Microcontroller relay driver and interface electroschematics. A relay should not be directly connected to a microcontroller, it needs a driving circuit. Interfacing principles apply to other arm microcontrollers and other nonarm microcontrollers as well. Relay interfacing with microcontroller using uln2003a the. Vdd and vss of the pic microcontroller is not shown in the circuit diagram. Interfacing highvoltage applications to lowpower controllers a common requirement of industrial applications is to interface highvoltage potentials, such as signal outputs of sensor switches and ac rectifiers, to the peripheral input ports of lowvoltage microcontrollers mcus and digital signal processors. This resistor limit the current and only very small current flows from the base to the emitter. The steps involved in interfacing an lcd with 8051 1.
Relay interfacing with pic microcontroller pic16f877a. From the above equation the value of r3 comes out to be 5. Relay module interfacing with pic16f877a microcontroller ac load. The lcd module interface with a microcontroller is simple and it is a primitive means of adding a visual appeal to your embedded application. Aug 17, 2017 figure 1 shows the basic relay driver circuit. Jul, 2015 interfacing circuits with microcontrollers, in this article i have discussed various elements and circuits interfacing with microcontrollers. Microcontroller interfacing techniques document revision. Jun 12, 2018 in this project we will interface a relay with pic microcontroller pic16f877a. Microcontroller interfacing circuits pdf 44p download book. The transistor is driven into saturation turned on when a logic 1 is written on the port pin thus turning on the relay. The image below show the schematic symbol for a npn transistor. Write the command to the datacommand port of the lcd through our 8051 microcontroller. Relay interfacing with pic microcontroller pic16f877a circuit digest.
A relays is an electrical switch that opens and closes under control of another electrical circuit. Martin bates has drawn upon 20 years of experience of teaching microprocessor systems to produce a book containing an excellent balance of theory and practice with numerous working examples through. See the block diagram below to how we turn on or off a 230 volt ac bulb by micro controller. Interfacing a relay with microcontroller electronics.
Relay for interfacing with 8051 microcontroller datasheet. A relay is an electromagnetic switch which is used to switch high voltagecurrent using low power circuits. Relay for interfacing with 8051 microcontroller datasheet, cross reference, circuit and application notes in pdf format. The comparator is used in place of the adc for the.
Interfacing highvoltage applications to lowpower controllers. Electromechanical relays interfacing circuits with. Relay is very important component to interface the heavy appliances with the help of microcontroller. The 8051 is the first microcontroller of the mcs 51 family introduced by intel corporation at the end of the 1970s. Oct 21, 2014 for interfacing relays, a npn transistor is generally preferred. So by using relay switch we easily turn on or off any high voltage device by microcontroller. Analog to digital converters sampling rate mhz sampling resolution bits. In todays tutorial, i am gonna show you relay interfacing with microcontroller using uln2003a. A very small current flowing from base to emitter causes a large current to flow from collector to emitter. Electrical engineering stack exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Introduction to mechatronics and measurement systems.
There are two basic types of lcd modules in the market they are, character lcd and graphics lcd. Wireless communication using rf module and interfacing. Relay isolates low power circuits from high power circuits. Microcontroller 8051 the intel 8051 microcontroller is one of the most popular general purpose microcontrollers in use today. Interrupts are the events that temporarily suspend the main program, pass the control to the external sources and execute their task. Due to my ladder logic compiler, i often get questions on how to build hardware to connect a micro to the outside world. Sequential control functions using the programmable relay switch and it generates acceptable. Much of the material online is wrong or incomplete, or reflects good practice circa 1970. You can connect seven relays using uln2003 and eight relays using uln2803. The completed prototype circuit board is shown in photo 1. Interfacing is a technique that has been developed and being used to solve many composite problems in circuit designing with appropriate features, reliability, availability, cost, power consumption, size, weight, and so on.
Matrix keypad can be connected to the microcontroller in numerous ways or techniques, but the fundamental logic is same as making the columns as input and the rows as output. The input is taken from the microcontroller pins and the output corresponding to each input is given to the 5 relays on the output. Automatic street light control using 8051 micro controller,keil ide and proteus simulation duration. Both microcontrollers and microprocessors are complex sequential digitalcircuits meant to carry out job according to the program instructions. Interfacing relay with pic microcontroller mikroc electrosome. Interfacing relay with pic microcontroller using uln2003. As you can see an npn transistor bc547 is being used to control the relay. Interfacing to the pic microcontroller this section explains how to interface many different input and output devices to the pic microcontroller. These circuits are useful for those who want to work on embedded system projects, but thy dont have a knowledge of electronics and embedded electronics. Here you can see that output from microcontroller enter transistor via resistor r1 4k7. Using the microchip pic18 family as a reference, it explains the architecture of the computer and the pic18 microcontroller, discusses how to program in both assembly and in clanguage, and then provides a solid discussion of interfacing, complete with a diverse set of examples. Interfacing circuits with microcontrollers, in this article i have discussed various elements and circuits interfacing with microcontrollers. Matrix keypad interfacing with 8051 microcontroller. Introduction to arm cortexm microcontrollers is an introduction to computers and interfacing focusing on assembly language and c programming and could be delivered at the college level with little or no prerequisites.
For interfacing relays, a npn transistor is generally preferred. A 32bit arm7 microcontroller is used in interfacing and software examples. It then passes the control to the main program where it had left off. Ted salazar, applications engineering manager sep 29, 2003 abstract. Octocouplers are fascinating devices used to isolate the electronic and electrical circuits. The relay is a good one for resistive loads like incandescent lamps. Introduction to octocouplers and interfacing with atmega8. Interfacing dc motor with pic microcontroller using l293d.