Discussion in "Project Help" started by    Pater    Apr 20, 2018.
Fri Apr 20 2018, 02:40 PM
#1
Actually I want to transmit 3 bits serially using AT89C51 micro-controller.

I have written the code in ".c" file, using c programming trying to transmit the bits serially using SBUF register.

As the SBUF register is the single register available in serial programming of 89C51, it is not updating its value. The bit which is first transmitted is only repeated in the next 2 bits, it is not being updated and then transmitted.

So I want guidance regarding sending 3 bits(number / integer) using serial communication( with SBUF register).

Following is the code I have written,

#include<reg51.h>

void decimal();
void MSB();
void MIDDLE();
void LSB();

void main()
{
while(1)
{
decimal();

MSB();

MIDDLE();

LSB();


}

}

void decimal()
{
unsigned char x,bin,d1,d2,d3;

bin = Data_Bus;
x = bin /10;
d1 = bin %10;
d2 = x %10;
d3 = x/10;

}

void MSB()
{
unsigned char d1,a;
TMOD = 0X20;
TH1 = 0XFD;
SCON = 0X50;
TR1 = 1;
a = d1 +0x30;
SBUF = a;
while(TI==0);
TI = 0;

}

void MIDDLE()
{
unsigned char d2,b;
TMOD = 0X20;
TH1 = 0XFD;
SCON = 0X50;
TR1 = 1;
SBUF = 0x00;
b= d2 + 0x30;
SBUF = b;
while(TI==0);
TI = 0;
}


void LSB()
{
unsigned char d3,c;
TMOD = 0X20;
TH1 = 0XFD;
SCON = 0X50;
TR1 = 1;
SBUF = 0x00;
c= d3 + 0x30;
SBUF = c;
while(TI==0);
TI = 0;
}
Sat Apr 21 2018, 07:45 PM
#2
I have attached sample code to do what you want.

There are a couple of points to note.

When you declare a variable in a function
it only exists in that function.
Variables d1,d2,d3 declared in void decimal() can't be
seen anywhere else.
When you declare d1 in MSB() it is a new variable (value 0 or unknown).

Declare d1,d2,d3 as global.

The serial port only needs to be set up once,
not every time it is used.

When functions do very much the same thing
as MSB(), void MIDDLE() and void LSB() do
find a way to use one call for all three.
Such as passing the variable to print.

sendChar(char c) does that.

Attachment


[ Edited Sat Apr 21 2018, 07:47 PM ]
 Pater like this.
Mon Apr 23 2018, 03:13 AM
#3
Thank You, ExperimenterUK for your valuable response.

You made it very clear for me to understand the errors and your sample code helped me to solve the issue.

Once again a big THANKS to you !!!
Mon Apr 23 2018, 08:51 PM
#4
Thanks
glad it helped

Get Social

Information

Powered by e107 Forum System

Conversation

ExperimenterUK
Mon Jan 07 2019, 03:31 AM
@REVOCATUS please post in the AVR forum
Mon Dec 24 2018, 09:25 AM
REVOCATUS MATEMU
sorry I mean referee boards for player substitution
Mon Dec 24 2018, 09:24 AM
REVOCATUS MATEMU
hi am.looking how to build referee by using Atmega 328 and its codes
Sat Dec 15 2018, 01:45 PM
Arslan ayoub
Hii ,, can I get the simulation of numeric keypad lock on proteus
ExperimenterUK
Mon Dec 03 2018, 05:17 PM
Please post questions in the forum. The chat box is for chat
Mon Dec 03 2018, 06:43 AM
help!me!
help! I don't understand busy flag!
Sun Dec 02 2018, 08:01 PM
ile
hello
Mon Nov 12 2018, 05:58 AM
Pavan_user
i have seen your replica of I2C programming using AT89C51 but i am unable to understand the "ack_bit" variable usage ...looks like it is always 1...can you elaborate how acknowledgment is working....
bgk3678
Tue Nov 06 2018, 02:36 PM
kindly any one give solution for my problem
ExperimenterUK
Mon Nov 05 2018, 09:48 PM
Pins high is the normal state. You need a program to set them low

Downloads

Comments

Kheirodin
Tue Jan 22 2019, 11:54 PM
garfield0929
Sun Jan 20 2019, 12:48 AM
servprov
Thu Jan 17 2019, 06:44 AM
marcomilazzo
Wed Jan 16 2019, 04:21 PM
sandhyashree
Wed Jan 16 2019, 04:04 PM
SONACHAI1234
Sun Jan 06 2019, 08:14 AM
manan.gulyaani
Tue Jan 01 2019, 07:58 AM
etech
Sun Dec 30 2018, 07:44 PM

Online

Guests: 61, Members: 1 ...
Kheirodin viewing chatbox_menu.php

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 38040
Newest member: Kheirodin
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Sun Jan 06 2019, 10:37 PM
Which 8051 chip are you using ?
SONACHAI1234 Avatar
Posted By SONACHAI1234
Sun Jan 06 2019, 08:21 AM
Hi,By mistakenly i burn rx program in my 8051 micr...
ExperimenterUK Avatar
Posted By ExperimenterUK
Wed Dec 19 2018, 06:27 PM
Nobody knows?sifirsekizThe problem is that you are...
sifirsekiz Avatar
Posted By sifirsekiz
Wed Dec 19 2018, 12:15 PM
sifirsekiz Avatar
Posted By sifirsekiz
Sun Dec 16 2018, 11:13 PM
Guys pleaseeeee :((
sifirsekiz Avatar
Posted By sifirsekiz
Sat Dec 15 2018, 07:09 PM
HiThe pulse-sensor-amped has an analogue output.Th...
ExperimenterUK Avatar
Posted By ExperimenterUK
Sat Dec 15 2018, 07:01 PM
HiThe pulse-sensor-amped has an analogue output.Th...
sifirsekiz Avatar
Posted By sifirsekiz
Sat Dec 15 2018, 09:02 AM
and ı have pulse sensor one out but anolog use 805...
sifirsekiz Avatar
Posted By sifirsekiz
Sat Dec 15 2018, 08:56 AM
HiMembers can supply code and diagrams if they wan...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Dec 14 2018, 11:54 PM
HiMembers can supply code and diagrams if they wan...