Digital voltmeter using 8051 microcontroller Essay

Voltmeter utilise 8051 microcontroller.Automatic railroad gate control 8051 microcontroller use adminOctober 4 20127 CommentsVoltmeter victimisation 8051.A simple 0-5V voltmeter using 8051 is shown in this article. This somaal voltmeter has a sensitivity of 200mV which is a bit low scarce this project is meant for demonstrating how an ADC and seven constituent discover lowlife be embrasured to 8051 to obtain a digital readout of the stimulus voltage.A 31/2 digit high end voltmeter on the wholeow be added soon. ADC0804 is the ADC and AT89S51 is the controller apply in this project. Before attempting this project, go through and through these projects Interfacing ADC to 8051 and Interfacing seven segment vaunting to 8051 which pull up stakes give you a good idea on the basics. enlistment diagram.0-5 digital voltmeter using 8051About the circuit.In the circuit Vref/2 (pin9) of the ADC is left open and it means that the foreplay voltage span can be o to 5V and the step size will be 5/255 = 19.6mV. The equation for the digital make of ADC0804 is Dout = Vin/Step size. In this circuit, for an arousal voltage of 1V the digital payoff will be 1/19.6mV = 51 and so the binary equivalent of 51 ie 00110011.Digital output of the ADC is interfaced to P1.0 of the microcontroller. experience signals for the ADC ie CS, RD, WR and INTR atomic number 18 avai research lable from the P3.7, P3.6, P3.5 and P3.4 pins of the microcontroller respectively. 2 digit multiplexed seven segment display is interfaced to Port0 of the microcontroller. Control signals for the display driver junction transistors Q1 and Q2 are obtained from P3.2 and P3.1 of the microcontroller. Push button twitch S1, capacitor C2 and resistor R10 forms a debouncing readjust circuitry.Program.ORG 00HMOV P1,11111111BMOV P0,00000000BMOV P3,00000000BMOV DPTR,LABELMAIN CLR P3.7SETB P3.6CLR P3.5SETB P3.5WAIT JB P3.4,WAITCLR P3.7CLR P3.6MOV A,P1MOV B,10DDIV ABMOV B,2DMUL ABMOV B,10DDIV ABSETB P3.2 ACALL DISPLAYMOV P0,AACALL surviveMOV P0,10000000BACALL frustrateMOV A,BCLR P3.2SETB P3.1ACALL DISPLAYMOV P0,AACALL tallyCLR P3.1SJMP MAIN crack MOV R3,02HDEL1 MOV R2,0FAHDEL2 DJNZ R2,DEL2DJNZ R3,DEL1RETDISPLAY MOVC A,A+DPTRRETLABEL DB 3FHDB 06HDB 5BHDB 4FHDB 66HDB 6DHDB 7DHDB 07HDB 7FHDB 6FH closeAbout the program.At first the program controls the ADC to produce a digital output corresponding to the input voltage.This digital output is scanned through P1.0 and is loaded to gatherer. Then the value in the accumulator is divided by 10 to omit the last digit. For example, let the input voltage be 4V. Then the corresponding digital output of the ADC will be 204D (D stands for decimal) .After the the division by 10, the value left in the accumulator will be 20D. This 20D is then multiplied by 2D which results in 40D.The next target of the program is to parry this 40D and make a 4.0 readout on the display. For this the 40D is again divided by 10D . This results in 4 inside accumulat or and 0 inside B register. Then the program gets the digit drive pattern for 4 using the lookup table , puts this pattern on Port 0 and activates Q1. After 1 ms sustain 10000000B is loaded to P0 and this accounts for the dot.After a further 1ms delay Q1 is deactivated, content in B (ie 0) is moved to A, gets the reform digit drive pattern for 0 using the lookup table, puts this pattern on Port 0 and activates Q2. After a further 1ms delay Q2 is deactivated and the entire cycle is repeated.8051 Microcontroller Projects & CircuitsadminFebruary 1 20138 CommentsIn this article we are itemisation all the projects and circuits we have true using the 8051 micro controller. We have tested all of these projects in our lab and verified the working . Allthese projects are made to solve a real world prerequisite or problem. Engineering students & former(a) diploma students will find these projects useful for their mini project and important project requirements.All the 8051 projects li sted below are made using the 8051 compliant microcontroller from Atmel AT89S51. We have given the slouch circuit diagram, working and software code (in assembly language) for each and every project. You can use all of them freely for your project & learning requirements. In case you are using a controller other than AT89S51 please be sure to check the hardware of your controller and compare it with that of AT89S51.This is necessary because we have developed all the software in assembly language. If you are not that good at assembly language, you can convert the software into C language & use it with any compliant 8051 controller.Image Source1. supersonic Range Finder using 8051 This project as the name says, is an application to measure distance of an object. It uses an inaudible transducer module HC-SR04 to measure the distance and the controller AT89S51 to make the necessary processing. This project can be used to make applications the like Automotive parking sensor, Obstac le warning systems, Terrain monitoring robots etc. This ultrasonic ordain finder can measure distances upto 2.5 meters with an accuracy of 1 cm.2. Digital Tachometer using 8051 This project is a digital tachometer which can be used to measure the revolutions per second of any object like a rotating wheel or a disc or a shaft. This application built using 8051 micro controller can measure upto 255 revolutions/second with an accuracy of 1 rev/sec. This application has 3 important sections 1) is the optical pickup designed to pick the revolutions of the object using a photo transistor and LED. 2) is the processing stage designed using 8051 and the associated software 3) is the display section using 7 segment displays.3. Water Level Controller using 8051 This is one of the most popularproject we have promulgated using 8051 controller. This water level controller monitors the level of the over drift tank and automatically switches on the water pump when ever the level goes below a p reset limit. The level of the over head tank is indicated using 5 leds and the pump is switched of when the over head tank is filled. We have given an illustrated circuit diagram with working explained in detail. You will also find the software codes written in pitch language.4. Voltmeter using 8051 We all must have used a multimeter from our young days. Have you ever bothered to create one ? So here is one such an interesting project. A Voltmeter using 8051 micro controller. Even though its quiet simple and an easy to make one, you shall find it really interesting. This can be used as an application at the mini project level for engineering and diploma students.This digital voltmeter can measure 0 to 5 volts and has a sensitivity of 200mV which is a bit low but this project is meant for demonstrating how an ADC and seven segment display can be interfaced to 8051 to obtain a digital readout of the input voltage. ADC0804 is the ADC and AT89S51 is the controller used in this projec t.5. Thermometer using 8051 This is an interesting project designed to measure temperature using 8051. Its a simple 0-100C digital thermometer with 1C resolution using 8051. The circuit is based on LM35 analog temperature sensor, ADC0804 and AT89S51 microcontroller. LM35 is an analogue temperature sensor IC which can measure a temperature range of -55 to 150C. Its output voltage varies 10mV per C change in temperature.Knowledge Resources- The articles below given are basics on how to work with 8051 micro controller. You can refer them if you come across a road block anywhere1. Interfacing 7 segment display to 8051 A good tutorial on interfacing 7 segment display to 8051 micro controller.2. Interfacing LCD display to 8051 Explains how to interface a 162 LCD display with 8051 micro controller.3. Interfacing DC motor to 8051 Explains how to interface a DC motor with 8051 micro controller.4. Interfacing push button switch to 8051 Interfacing LED & Push button switch to 8051 micro controller.5. Interfacing ADC to 8051 This articles gives you a good detail on how to interface ADC to 8051 micro controller. ADC 0804 is used to explain the interfacing procedure with an example software routine.8 channel light pursuer using 8051adminMay 10 201210 Comments6 function 8 channel light chaser using 8051. A 6 function 8 channel light chaser using 8051 is shown here. The hardware and software of this circuit are very simple and the light functions gets repeated one after another automatically. P1.0 to P1.7 of the microcontroller (AT89S51) are assigned as the output pins.Corresponding LEDs are connected to the output pins through 1K current limiting resistors (R1 to R8). The sequence by which the output pins (P1.0 to P1.7) goes high and low is determined by the program and the LEDs follow this sequence. Circuit diagram of the 6 function chaser using 8051 is shown below.6 function light chaser using 8051Program.START MOV A,80HMOV R7,07HMOV P1,ALCALL DELAYLABEL1 RR AMOV P1,ALCALL DELAYDJNZ R7,LABEL1MOV R7,07HLABEL2 RL AMOV P1,ALCALL DELAYDJNZ R7,LABEL2MOV P1,81HLCALL DELAYMOV P1,42HLCALL DELAYMOV P1,24HLCALL DELAYMOV P1,18HLCALL DELAYMOV P1,0FFHLCALL DELAYMOV P1,00HLCALL DELAYMOV A,80HMOV P1,ALCALL DELAYMOV R7,07HLABEL3 SETB CRRC AMOV P1,ALCALL DELAYDJNZ R7,LABEL3MOv P1,00HLCALL DELAYMOV A,0AAHMOV P1,ALCALL DELAYCPL AMOV P1,ALCALL DELAYLJMP STARTDELAY MOV R4,03HWAIT1 MOV R3,00HWAIT2 MOV R2,00HWAIT3 DJNZ R2,WAIT3DJNZ R3,WAIT2DJNZ R4,WAIT1RETEND