http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. en-gb 2009-01-08T04:59:42-08:00 contact@nospam.com hourly 1 2000-01-01T12:00+00:00 http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 plz tell me that which microcontroller is used in the project "automatic room light controller with visitor counter" ?? In the description of the project 89c2051 is mentioned but in the circuit diagram 89S52 is used??????? http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay i just checked.. the controller used is same 89c2051 here is the screenshot of the circuit. you might have downloaded a wrong file i think. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha sir, this is the screen shot of circuit diagram of project "digital visitor counter" not that of the "automatic room light controller with visitor counter" ...........plz check that ... and also the code available for this project is not complete ,, it is only the following;INCLUDE reg_51.pdfP1 EQU LEDSORG 000HSTART:MOV LEDS,#0FFH CALL DELAY MOV LEDS,#00H CALL DELAY JMP START1;**********************************************************DELAY: MOV R1,#4FHREP2: MOV R2,#0FFHREP1: NOP DJNZ R2,REP1 DJNZ R1,REP2 RET;********************************************************** ENDplz reply soonthanks http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay Isha have a better option for you.. if you simply modify the digital visitor counter project.. add some functionality for switching off the bulb when counter is 0 and switch on as soon as count is greater than 0... that will be a good option... if you want to try it.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha Thanks sir i think i should first try "digital visitor counter" and then i'll try to modify that...can u plz give some details of circuit diagram of "digital visitor counter" , functionality of each component , specially that of transistors , seven segment displays and LDRs... how do they work??? http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay Isha can you please wait.. i need to contact the Author of the project and inform him about the problem. His projects contain so many error.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay ok might be my mistake.. i will check and get back to you.. and.. keep the doubts about a single project in a single thread.. so i am going to delete the other thread you created ok http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay check you previous post.. i actually explained the working of digital visitor counter.. see your last posted thread.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ritesh the transistors are used to drive the common cathode of each 7 segment display, the displays here are used with multiplexing technique means there is only one display works at a time but it shifts so fast therefor all display works simultaneouslythe two LDR's here use for input as active low. means initially it is in high state (1)and it get input by grounding the pins (or 0) http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay check this post where i explained the working http://www.8051projects.net/forum-t1190.html http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay you can write yourself.. if you want and sure i will help you to do it. But keep in mind efforts are going to be yours.. i will just guide http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay I have got the new updated file from the author and download is also updated now.. so if you want, you can download the updated code... http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha is the code for "digital visitor counter " available in C language?????????or is there any way to convert the assembly language code to the C language????? http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha i just need to know how to start ???i think i can do that.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha i just need to know how to start ???i think i can do that.. i've good programming skills. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay Isha, I read your PM but cannot see the screenshot, can you attach it here?and the other three displays will be connected to the same port as shown in the circuit, but the Common pin of the 7-seg will be connected to different pins as shown in circuit. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha or plz tell me how to attatch an image here???? http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha actually i did'nt know how to attath an image here, that's why i sent u in PM.i'm sending u in another PM , plz chek that ... http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha screen shot is attached: http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay now you know how to attach.. is really simple..or.. what you can do is.. visit www.imageshack.us and upload your file there.. and copy the direct link to image and put it inside [ img] and [/ img] tags, that will display your image automatically.And i have seen the circuit.. all you have to do is.. the wires from the Port 1 will be connected to all the 4 7-seg displays, you have just connected to 1. So take the same wires and connect them to all.. common is connected to diff pins with the help of transistors and with switch the display one by one.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay hm... before starting that.. i want to ask you some questions.. which IDE (software for compiling) you are using? and are you familiar with that IDE? if yes then how much...because understanding the IDE is the first important thing. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha sir, plz guide me how to start programming the project "digital visitror counter " in C language?????????? http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ritesh hi ishaplease refer the book "Embedded C"it is used c for programming 8051 with some useful examples suited to your requirement and most good thing is that it use same keil the book is already posted in the e-book download section or click this linkhttp://www.8051projects.net/forum-t1260.html http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha sir , i'm using keil uvision for the project, and i m familiar with that , i've used that for a counter(0-30) project..... http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay Thats good if you have already worked on it oce..so.. simply define the ports which you are using in your project. you can define in two ways...Fitst:#include #define port_name porte.g. #define abc P1and pin can de defined as..#define def P2_1Second:defining bit-sbit abc=0x81;defining port or other sfrsfr def = 0x90;after that you start writing your program in C as you write normally. you can make fuctions or simply write the whole program in a single function called main()please start writing something afterwards i will explain you.. as you go on. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha i've defined the ports which are used in the project,plz tell me how to initialize the timer?and how to program the ports where transistors are attatced and the ports where ldrs are attatched????plz reply soon http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay ok... setting up the timer is very simple. putting value in register is same like moving value to a variable. you can open the file you included "AT89X51.H" and see how the registers have defined in it.so timer can be set like this way...TMOD = 0x20; // timer mode settingTH1 = 20; // put value in Timer 1 high byteTL1 = 3; // put value in Time 1 low byteTR1 = 1; // run the timerthis way you can do the same for timer 0 you can do.you can enable the timer interrupt as..ET1 = 1; // Timer 1 interruptEA = 1; // global interruptwriting interrupt routine..void timer1_isr() interrupt 3{ // your codeTF1 = 0; // clrear Timer overflow flag//other code}Interrupt numbers..Exter. int 0 - 0timer int 0 - 1Exter. int 1 - 2timer int 1 - 3RX/Tx int - 4similar with the ports.. P1 = 0x40; //some valueport... pin..P1_1 = 1 or 0; // setting or clearing a pin..checking pin is set or cleared..if(P1_1){ //execute the code if Port 1 pin 1 is set//code}else{ //execute the code if Port 1 pin 1 is clear//code}or you can sometime have this way too..if(!P1_1){ //execute the code if Port 1 pin 1 is clear//code}else{ //execute the code if Port 1 pin 1 is set//code}making a port o/pP1 = 0;making a port i/pP1 = 0xFF;making a port pin i/pP1_1 = 1;making a port pin o/pP1_1 = 0;Please you can move on with your code now.. if any problem tell me.. http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha sir, i 've started programming in C language but i'm having problems ... why four seven segments have been used and why they are all connected to the same port? and what about their common cathodes where transistors are attathed?? how current pass through??? how to program those pins???plz reply soon... http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay welcome back isha you came back after a long time.. anyways.. four segments are connected to same port just to save pins. otherwise you need 32 pins to connect four 7-seg but now you are just using 12 pins (4 common control and 8 data).transistor will switch the seven segments on one by one. As you know the phenomenon "persistence of vision" of human eye.. so the 7-segments are going to be switched one by one so fast that human eye will think all of them as ON!!this is done in C like this.. CODE:    7seg_port = 7seg_decode(digit1);
    7seg1_cathode = 1;
    some_delay();
    7seg1_cathode = 0;
    7seg_port = 7seg_decode(digit2);
    7seg2_cathode = 1;
    some_delay();
    7seg2_cathode = 0;
    7seg_port = 7seg_decode(digit3);
    7seg3_cathode = 1;
    some_delay();
    7seg3_cathode = 0;
    7seg_port = 7seg_decode(digit4);
    7seg4_cathode = 1;
    some_delay();
    7seg4_cathode = 0;
 So the above thing is done continuously..explaination:7seg(1,2,3,4)_cathode are the pins connected to transistor. making it 1 will activate the transistor and current flows from power via LED of 7-seg to ground.7seg_port is the port where all 7-segment displays are connected.7seg_decode(digit variable) this function gets an input digit which is going to be displayed. for example 0 is the digit to be displayed.. but you cannot directly send 0 to the port. so what you need to do is, get which LED has to glow on 7-seg (a,b,c,d,e,f,g) the dot LED is considered usually always off or as per you need.. e.g 0 is displayed on 7-seg like this..|¯||_|So to get this u need LED a,b,c,d,e,f as on so the decoded value for zero will beCODE:
val     a   b  c  d  e  f   g   dot   Decoded
 0      1   1  1  1  1  1   0    0        0x3Fthe above value is calculated as.. a is connected to Port pin 0, b with pin 1 and so on.. dot with dot with pin 7 of the port.So once the decoded value is sent to the port.. switch the 7-seg on by switching the corresponding transistor. and then switch it off after some time.. this delay is provided by some_delay routine and the value of delay is selected according to your need.. just to avoid flickering on the display.so this step by step switching will display the digits one by one so fast that.. user looking at the display will think that all 7-segments are ON!I hope i am clear.. how to use 7-segments. If you still have doubt please feel free to ask http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 isha i tried it , but same digit is displayed on all the displays, what should be done if i have to display 11, 12 , or 100 or 1122 etc.... http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay then you have to get the digits..e.g if you have 23 then on 7-seg it will be displayed as 0023 or just 23..you can split the digits as.. first dividing it by 1000 then 100, then 10, the left one is the last digit.. i hope you understood http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 msmuneer86 hello,i am really confuse in the connection of 7 segment display with the microcontroller. please help me. i mean to say 'a' of 7segment is connected to which pin of microcontroller etci cannot open the file reg_51.pdf because adobe reader is giving error that it is either not supported or file is damage.please give another link http://www.8051projects.net/forum-t1201.html 2009-01-08T04:59:42-08:00 Ajay it contain all the register definations... nothing else.. do not need to open it.regarding 7-segment... if you have read the program carefully then you can see at the top... the connections of 7-segments are explained very clearly.. asCODE:DIS_A   EQU     P1.5
DIS_B   EQU     P1.4
DIS_C   EQU     P1.3
DIS_D   EQU     P1.1
DIS_E   EQU     P1.2
DIS_F   EQU     P1.6
DIS_G   EQU     P1.7