The comparator is used in place of the adc for the. Interfacing lcd module with microcontroller embedjournal. Interfacing the max1169 adc to a pic microcontroller by. The 8051 is the first microcontroller of the mcs 51 family introduced by intel corporation at the end of the 1970s. Mar 02, 20 interfacing relay with pic microcontroller using uln2003. Relay provides isolation between two voltage levels and it is generally use to control ac appliances. Picaxe microcontroller interfacing circuit revolution education. The input is taken from the microcontroller pins and the output corresponding to each input is given to the 5 relays on the output. The pic 16f877a pic microcontroller is one of the most popular general purpose. Relay for interfacing with 8051 microcontroller datasheet. Relay interfacing with pic microcontroller pic16f877a circuit digest. This application note describes how to interface a max1169 analogtodigital converter adc to a pic microcontroller. Atmega8 microcontroller, power supply 5v, avrisp programmer, 4n25 optocoupler, 1k. As you can see an npn transistor bc547 is being used to control the relay.
Microcontroller 8051 the intel 8051 microcontroller is one of the most popular general purpose microcontrollers in use today. Development of programmable relay switch using microcontroller. In this project report description of inputoutput interfacing of microcontroller and the program, which is. Interfacing a relay with microcontroller electronics. Internally relay consist of a coil of wire wrapped soft iron core. I have not been able to find a good reference to suggest. A relay should not be directly connected to a microcontroller, it needs a driving circuit. Electromechanical relays interfacing circuits with. 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. Write the command to the datacommand port of the lcd through our 8051 microcontroller. The circuit diagram for optocoupler interfacing with avr microcontroller is shown in figure. Microcontroller 8051 and its interfacing linkedin slideshare. Microcontroller interfacing to relays using uln2003, in this article, you will learn how to interface microcontroller to relays using uln2003 relay driver circuit. The steps involved in interfacing an lcd with 8051 1.
Both microcontrollers and microprocessors are complex sequential digitalcircuits meant to carry out job according to the program instructions. Have you ever wondered how your pc and phones keep track of time even when the device is turned off. Relay module interfacing with pic16f877a microcontroller ac load. Here you can see that output from microcontroller enter transistor via resistor r1 4k7. Relay for interfacing with 8051 microcontroller datasheet, cross reference, circuit and application notes in pdf format.
A relays is an electrical switch that opens and closes under control of another electrical circuit. The input is taken from the microcontroller pins and the output corresponding to each input is given to the 5. Much of the material online is wrong or incomplete, or reflects good practice circa 1970. The completed prototype circuit board is shown in photo 1. 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. The lcd module interface with a microcontroller is simple and it is a primitive means of adding a visual appeal to your embedded application. From the above equation the value of r3 comes out to be 5.
Microcontroller interfacing circuits pdf 44p currently this section contains no detailed description for the page, will update this page soon. 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 principles apply to other arm microcontrollers and other nonarm microcontrollers as well. Ted salazar, applications engineering manager sep 29, 2003 abstract. Relay is very important component to interface the heavy appliances with the help of microcontroller.
Programming and interfacing the 8051 microcontroller in c and. To understand how microcontroller works as a multifunctional relay it is necessary to know about microcontroller working, functions and its applications. In todays tutorial, i am gonna show you relay interfacing with microcontroller using uln2003a. This section will help to enable those with limited electronics experience to successfully complete these interfacing tasks. Relay isolates low power circuits from high power circuits. 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. Aug 17, 2017 figure 1 shows the basic relay driver circuit.
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. Its a simple wirewrapped board with all throughhole components except the adc. The agsno2 contacts can handle higher inrush currents than agni. This simple device isolates the sensitive electronics from robust electronics like motors, yet keeping the load in control over the source. Different dc motors need different voltages and operating high voltage motor from a low voltage controller is not a feasible option.
Microcontroller is a programmable digital processor with necessaryperipherals. To interface relay with microcontroller we need a driver circuit to drive the power to relay. Jun 12, 2018 in this project we will interface a relay with pic microcontroller pic16f877a. 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. See the block diagram below to how we turn on or off a 230 volt ac bulb by micro controller. Interfacing of relay with microcontroller aticleworld. Oct 21, 2014 for interfacing relays, a npn transistor is generally preferred. A 32bit arm7 microcontroller is used in interfacing and software examples. Following things should be taken into account while designing the. It should not be directly connected to a pic 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. This book provides a comprehensive look into the architecture, programming, and interfacing of the microcontroller. Wireless communication using rf module and interfacing with. Before interfacing, every one should know about the relay driver which is used to interface the relay to microcontroller. Programming and interfacing the 8051 microcontroller in c. Wireless communication using rf module and interfacing.
Relay interfacing with microcontroller using uln2003a. How to turn on and turn off relay with pic microcontroller by using digital output ports of pic16f877a microcontroller. Interfacing methods of microcontroller linkedin slideshare. May 21, 2016 automatic street light control using 8051 micro controller,keil ide and proteus simulation duration. 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. Microcontroller interfacing to relays using uln2003 relay. Relay interfacing with pic microcontroller pic16f877a. The image below show the schematic symbol for a npn transistor. 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. Interfacing the max1169 adc to a pic microcontroller. 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.
Jul, 2015 interfacing circuits with microcontrollers, in this article i have discussed various elements and circuits interfacing with microcontrollers. These are monolithic ic s consists of high voltage high current darlington transistor arrays. Interfacing hcsr04 ultrasonic rangefinder with pic 16f877a microcontroller dht11 humidity sensor interface with pic16f877a p10 rg led display interface with stm32f030f4 32bit mcu. The potentiometer is used to adjust the reference voltage for the microcontrollers onchip analog comparator. In this tutorial we are going to interface an optocoupler with atmega8 microcontroller. The 8051 family with its many enhanced members enjoys the largest market share, estimated to be about 4 0%, among the various microcontroller architectures. Basic code examples are provided for users of the basic. Matrix keypad interfacing with 8051 microcontroller. There are two basic types of lcd modules in the market they are, character lcd and graphics lcd. So we connect output from our microcontroller pin to the base of transistor.
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. Interfacing to the pic microcontroller this section explains how to interface many different input and output devices to the pic microcontroller. Relay interfacing with microcontroller using uln2003a the. A pic microcontroller is a single integrated circuit pic microcontrollers can be used as the brain. Now we are gonna have a look at how to interface this relay with microcontroller and then use it in your project. 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.
Applications of interfacing devices with microcontroller. Automatic street light control using 8051 micro controller,keil ide and proteus simulation duration. Relay interfacing with microcontroller 8051 microcontroller. A relay is an electromagnetic switch which is used to switch high voltagecurrent using low power circuits. Sequential control functions using the programmable relay switch and it generates acceptable. Programming with pic microcontroller research design lab. Interfacing highvoltage applications to lowpower controllers.
For interfacing relays, a npn transistor is generally preferred. 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. From mechanical to solid state relays, there are various type of relays are available in. Interrupts are the events that temporarily suspend the main program, pass the control to the external sources and execute their task. For detailed working of relay please visit this page. If you want to know more about relay driver circuit uln2003, relay working and relay interfacing with arduino check these articles. 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. Introduction to mechatronics and measurement systems.
Interfacing relay with pic microcontroller using uln2003. In this project we will interface a relay with pic microcontroller pic16f877a. Example programs are written in the c programming language. Interfacing relay with pic microcontroller mikroc electrosome. Oct 09, 2012 interfacing methods of microcontroller 1.
Analog to digital converters sampling rate mhz sampling resolution bits interface type parallel or serial reference voltage volt input range unipolar or bipolar. Each input is connected to the triggering coil of the respective relay. 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. Octocouplers are fascinating devices used to isolate the electronic and electrical circuits. Realtime operating systems for arm cortexm microcontrollers is an advanced. It includes an example circuit and software for a pic18f442. Microcontroller basics pdf slides 46p this book covers the following topics. Microcontroller interfacing circuits pdf 44p download book. Interfacing circuits with microcontrollers, in this article i have discussed various elements and circuits interfacing with microcontrollers.
Due to my ladder logic compiler, i often get questions on how to build hardware to connect a micro to the outside world. To facilitate multiple features with simple circuits, microcontroller is interfaced with devices such as adc, keypad, lcd. It is activated by energizing a coil wounded on a soft iron core. In my previous post, i have posted the first part of this tutorial in which i have shown you the introduction to relay also its working. 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. 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. If you want to use more relays, using transistors will be difficult. 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. 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 im connecting one relay in port b. You can connect seven relays using uln2003 and eight relays using uln2803. Relays are devices which allow low power circuits to switch a relatively high current andor voltage onoff. 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.
So by using relay switch we easily turn on or off any high voltage device by microcontroller. A microcontroller is a computer on a chip used to control electronic devices. Electrical engineering stack exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Introduction to octocouplers and interfacing with atmega8. Interfacing relay to microcontroller dna technology. Dc motors need much more current than a microcontroller can provide, so it needs separate drivers. Microcontroller relay driver and interface electroschematics. A very small current flowing from base to emitter causes a large current to flow from collector to emitter. 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. This resistor limit the current and only very small current flows from the base to the emitter. Define function for sending command to the lcd using 8051 a.
But have run into a problem while interfacing the micro controller with a relay. Here is a simple microcontrollerrelay interface circuit. The transistor is driven into saturation turned on when a logic 1 is written on the port pin thus turning on the relay. It then passes the control to the main program where it had left off. Analog to digital converters sampling rate mhz sampling resolution bits.
The relay is a good one for resistive loads like incandescent lamps. Relay is a mechanical device to control high voltage, high current appliances on or off from lower voltage levels. A pic microcontroller is a single integrated circuit small enough to fit in the palm of a hand. Vdd and vss of the pic microcontroller is not shown in the circuit diagram. Nov 02, 2012 in todays tutorial, i am gonna show you relay interfacing with microcontroller using uln2003a. 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. 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. Interfacing dc motor with pic microcontroller using l293d.
Well there is a real time clock rtc that is kept powered even is the device is turned off. Microcontroller interfacing techniques document revision. Ssrs make interfacing with ac voltage really, really simple. There are 2 output channels that each correspond to an input. A relay is a switch which is used to switch high voltage or current using low power circuits.
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