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receive serial data on 4 7 segements .


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guitar

Thu Jul 16 2009, 09:44AM

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Hello Sir,

I am trying to connect '4' 7segements to Microcontroller.The microcontroller will inturn receive data from serial port.
I am able to receive data and display on '4' 7 segements.for.eg if i am getting 1234 as serial data then only 1digit is displaying out of four above mentioned digits('1234') on all '4' 7 segments.I am attaching the .hex file,proteus design and my 'c' code.Kindly,suggest me for the same.

serial_trans.zip

tweety bird

Thu Jul 16 2009, 07:31PM

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Joined: Sat Apr 19 2008, 08:49PM

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though i havent seen ur proj , but still i ll try to giv u some suggestions...
receive data thru serial port, show them on 7 seg one by one..
when u rec 1st char, enable 1 st 7seg n disable all others n send data to it..
then u rec 2nd char, enable 2nd 7seg n disable all others, n send data to it...
n so on..
it should be simple ...

guitar

Thu Jul 16 2009, 08:26PM

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but i want all the 4 digits(1234) to display on each seven segment display simultaneously.
like ' 1' on 1st seven segment, '2' on 2nd seven segment , '3' on 3rd seven segment , '4' on 4th seven segment and so on. but each seven segment should display retain their value .

so that value appears to be '1234' on whole 4 7 segment display.

afilash

Fri Jul 17 2009, 12:58PM

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I can't able to open the circuit diagram you have send, could you please send it as a JPG?
i assume you are using multiplexing to display numbers in 7 seg using port P1?
if your program is like that given in the zip file it wont work !!!!
declare an array of length 4.
what you have to do just receive numbers one by one
convert each ASCII character to display_code
push those codes in to that array like a circular buffer
then
while the program is not receiving any ASCII character
pull the character_code from the array and send it through port P1 one by one simultaneously enable the correct seven segment
you have to do the last part in a loop!!!!!!

i will tell you what your current will do >>>
it will recive the ASCII > convert it to seg_code > push it out through P1
since all the enable lines are high during this process all the 7 seg will display the current character you have sent to the microcontroller
:mad

got it?

then reprogram your code !
or else we will help you :-)

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guitar

guitar

Fri Jul 17 2009, 01:49PM

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Joined: Wed Aug 27 2008, 04:15AM

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hello sir,
thanks for your valuable support.
I have understood the way you have described and would implement this way.
i want to know that..previously i was using a array[4].But ,it would only store the last value that came from serial port.Thus, i was not able to save and retrieve value for rest the data in array(array[1],array[2] and array[3].

afilash

Fri Jul 17 2009, 02:31PM

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No need to call me "Sir"
you can call me "abhi" or "afilash"
in your previous code , I assume that the array variable get initialized inside you serial_reception_code_section
any way rewrite it & show us :-)

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guitar

rahuljin

Sat Jul 18 2009, 12:39AM

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Joined: Fri Sep 07 2007, 01:19PM

Posts: 180
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here is some code ----

CODE:

#include <REGX52.h>

#include <stdio.h>

#include <math.h> 

unsigned int DIGI[4];

void Delay()

{

    unsigned int i;

    for(i=535;i>0;i--);

}

void display()

{

        P2_3 = 1;

        P1 = DIGI[0];

        Delay();

        P2_3 = 0;

        P2_2 = 1;

        P1 = DIGI[1];

        Delay();

        P2_2 = 0;

        P2_1 = 1;

        P1 = DIGI[2];          

        Delay();

        P2_1 = 0;

        P2_0 = 1;

        P1 = DIGI[3];          

        Delay();

        P2_0 = 0;

}

void main()

{

        unsigned int c;

    unsigned int i = 0;

            //I want to use the array to store '1234' values from serial ports.How can i do it?

        TMOD = 0x20;

    SCON = 0x50;

    TH1  = 0xFD;

    TL1  = 0xFD;

    TR1  = 1;

        for(i = 0; i < 4; i++)

        DIGI[i] = 0xC0;

    while(1)

        {          

                for(i = 0; i < 4; i++)

                {

                        while(!RI)

                        {

                        display();

                        }

                        c = SBUF;

                        RI = 0;

                        switch(c)

                        {

                                case 0x30: DIGI[i] = (0xC0);

                                        break;

                                case 0x31: DIGI[i] = 0xF9;

                                break;

                                case 0x32: DIGI[i] = 0xA4;

                                break;

                                case 0x33: DIGI[i] = 0xB0;

                                break;

                                case 0x34: DIGI[i] = 0x99;

                                break;

                                case 0x35: DIGI[i] = 0x92;

                                break;

                                case 0x36: DIGI[i] = 0x82;

                                break;

                                case 0x37: DIGI[i] = 0xF8;

                                break;

                                case 0x38: DIGI[i] = 0x80;

                                break;

                                case 0x39: DIGI[i] = 0x98;

                                break;

                                default: DIGI[i] = 0xBF;

                                break;

                        }

                          display();

                }

        }

}

the name is rahul

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guitar

Bohemian Strings

Sat Jul 18 2009, 07:04PM

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Joined: Sat Jul 18 2009, 11:33AM

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Hello Rahuljin,

I have a request. Can you rewrite the same C program using the function bioscom(), if you please? I have to do a similar sort of a job, but using bioscom() only... Please help if you can.
:-)

rahuljin

Sat Jul 18 2009, 07:49PM

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Joined: Fri Sep 07 2007, 01:19PM

Posts: 180
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what is bioscom() ? explain a bit so that i can help

[ Edited Sat Jul 18 2009, 07:50PM ]

the name is rahul

Bohemian Strings

Sat Jul 18 2009, 10:22PM

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Joined: Sat Jul 18 2009, 11:33AM

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Rahuljin,

bioscom() is a function that is used to support serial communication through RS 232. It can only be compiled in DOS based C editor and requires the header file <bios.h>. Please refer to my post Project: Serial communication between Microcontroller and PC in the 8051 discussion forum... I did explain everything there... Any kind of help will be really appreciated. I need this job to be done by tomorrow...

[ Edited Sat Jul 18 2009, 10:23PM ]