need to write C for 8051 : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes

Forums

8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes :: Forums :: Discuss and Learn :: 8051 Discussion Forum		<< Previous thread \| Next thread >>
need to write C for 8051

Go to page [1] 2
Moderators: Ajay, Junied , abbas1707, Arun Kumar V, pdi33, Shailesh NAYAK, ۞ TPS ۞, shyam, sashijoseph

Author

Post

UmerAhmed

Tue Nov 11 2008, 12:17PM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

Hi all, i'm new to this forum this is my first message, i'm trying to build a project with At89C2051 mc chip. it came with a burnt code that does the job, i just need to modify it to serve my project purpose

i have downloaded keil IDE that compiles for my device. This is a development kit for TR1000 tranceiver module. I do not have the original C code with me all i have is the HEX code. The PIN configuration is this:
Pin6 receive form transceiver
pin7 transmit to transceiver
pin2 receive from outside
pin3 tansmit to outside

originaly this chip is programmed to look for a certain start symbol to know when the message starts, and signal that i'm trying to catch does not have a start symbol in front of it, all i wanna do for starters is to latch the input that is coming from radio means Pin6 to Pin3 which is going to the outside

thanx for ur help

Umer

umer

ExperimenterUK

Wed Nov 12 2008, 11:15AM

Registered Member #9602

Joined: Tue Aug 05 2008, 04:15PM

Posts: 207
Thanked 38 times in 37 posts

UmerAhmed wrote ...

module. I do not have the original C code with me all i have is the HEX code. ...

originaly this chip is programmed to look for a certain start symbol to know when the message starts, and signal that i'm trying to catch does not have a start symbol in front of it, all i wanna do for starters is to latch the input that is coming from radio means Pin6 to Pin3 which is going to the outside

If all you wanted to do was to modify the code to not need to see the special start symbol
it might be worth dis-assembling the hex and patching it.
Once you think of doing anything more it's probably better to learn about the At89C2051
and write new code.

Learning all the time

UmerAhmed

Fri Nov 14 2008, 04:52AM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

thank you for the reply

i'm totally new to this, if anyone help me get started writing code for At89C2051 that is on board with a transceiver and also connected to PC through a serial port. I want to check if i received anything on pin6 blink an LED and then forward this on to Pin3

thanx

Umer

umer

UmerAhmed

Fri Nov 14 2008, 04:54AM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

here is the schematic for the circuit

img1.pdf

umer

pdi33

Fri Nov 14 2008, 08:07AM

Registered Member #1329

Joined: Mon Jun 04 2007, 09:28AM

Posts: 774
Thanked 186 times in 181 posts

UmerAhmed wrote ...

hi umer,
if u want to check the UART communication of the 8051 , then check the tutorial section under the same topic on this site. U will find the basics of writing the code. adding a blinking LED would not be difficult then. write some code, check it on hardware and get back if u have any doubts. u can use the hyperterminal on the PC side for checking transmission /reception of data on the PC.

* inspired to develop,developing to inspire *

UmerAhmed

Tue Nov 18 2008, 07:59AM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

Thank you for your response
i wrote this code for my At89c2051 but its not working if i can get some helpful pointers
that will be great

/*-----------------------------------------------------------------------------
Definitions for P1 (8 bits), P1.0, and P1.1.
-----------------------------------------------------------------------------*/
sfr P3 = 0xB0; /* SFR for P3 */

sbit P3_1 = P3^1; /* SFR for P3.1 */
sbit P3_2 = P3^2; /* SFR for P3.2 */
sbit P3_4 = P3^4; /* SFR for P3.4 */
sbit P3_5 = P3^5; /* SFR for P3.5 */
sbit P3_7 = P3^7; /* SFR for P3.7 */

/*-----------------------------------------------------------------------------
MAIN C function
-----------------------------------------------------------------------------*/
void main (void)
{
P3_2 = 1;
P3_4 = 1;
P3_5 = 1;
P3_7 = 1;

/*-----------------------------------------------
This loop reads P3.2 and writes the value read
to P3.1.
-----------------------------------------------*/
while (1)
{
P3_1 = P3_2; /* Copy P1.0 to P1.1 */
P3_4 ^= 0x01;
P3_5 ^= 0x01;
P3_7 ^= 0x01;
}
}

/*-----------------------------------------------------------------------------
-----------------------------------------------------------------------------*/

all i'm trying to do is to make the three LEDs connected to Pins 8,9 and 11 of the microcontroller to blink on each iteration of the loop also if i get anything on pin 6 of the MC i wanna copy that to pin 3

thank you

umer

sashijoseph

Tue Nov 18 2008, 08:54AM

Registered Member #5870

Joined: Mon Feb 04 2008, 06:26PM

Posts: 651
Thanked 141 times in 134 posts

Try inserting some delay at the end of the while loop,else the led's will blink too fast to notice.

Let there be music........

UmerAhmed

Sun Nov 23 2008, 08:51PM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

thanks for all the help !
i'm using keil IDE for development and having a little problem that i need help with
when i try to build target for At89C2051 for the following program
////////////////////////////////////
#include<AT892051.h>

#define ON 0
#define OFF 1
/*-----------------------------------------------------------------------------
MAIN C function
-----------------------------------------------------------------------------*/

//void delay (int);

void main (void)
{
//unsigned int ON_OFF = 0;
P3_2 = ON;
P3_4 = ON;
P3_5 = ON;
P3_7 = ON;
//P3 = 0xFF;

/*-----------------------------------------------
This loop reads P3.2 and writes the value read
to P3.1.
-----------------------------------------------*/
// delay(20000);
while (1)
{

P3_1 = P3_2; /* Copy P1.0 to P1.1 */
/* P3_4 = ON_OFF;
P3_5 = ON_OFF;
P3_7 = ON_OFF;
ON_OFF = ~ON_OFF; */
// delay(33000);
}
}
/*
void delay(int millisec)
{
int x=0;
int y=0;
for( x=0;x<millisec;x++)
{
//do nothing
/* for(;y<100;y++)
{
//do nothing
} */
/*
}
}
*/
///////////////////////////////////
if i generate output without selecting the - Use On-Chip ROM option from menu
Project->Options for Target Target1 -> Target tab
compile fails saying
//////////
Build target 'Target 1'
linking...
*** ERROR L107: ADDRESS SPACE OVERFLOW
SPACE: CODE
SEGMENT: ?PR?MAIN?MAIN
LENGTH: 000EH
*** ERROR L107: ADDRESS SPACE OVERFLOW
SPACE: CODE
SEGMENT: ?PR?MAIN?MAIN
LENGTH: 000EH
*** ERROR L107: ADDRESS SPACE OVERFLOW
SPACE: CODE
SEGMENT: ?C_C51STARTUP
LENGTH: 000CH
*** ERROR L107: ADDRESS SPACE OVERFLOW
SPACE: CODE
SEGMENT: ?C_C51STARTUP
LENGTH: 000CH
*** ERROR L120: CONTENT BELONGS TO ERRONEOUS SEGMENT
SEGMENT: ?C_C51STARTUP
MODULE: STARTUP.obj (?C_STARTUP)
*** ERROR L118: REFERENCE MADE TO ERRONEOUS EXTERNAL
SYMBOL: ?C_START
MODULE: STARTUP.obj (?C_STARTUP)
ADDRESS: 000AH
*** ERROR L105: PUBLIC REFERS TO IGNORED SEGMENT
SYMBOL: MAIN
SEGMENT: ?PR?MAIN?MAIN
*** ERROR L120: CONTENT BELONGS TO ERRONEOUS SEGMENT
SEGMENT: ?PR?MAIN?MAIN
MODULE: .\main.obj (MAIN)
Program Size: data=9.0 xdata=0 code=29
Target not created
///////////
if i create a hex file without selecting the above mentioned option it generates a .hex file
but that is referencing code outside of the address space of the ROM, so when i burn that on the chip
it fails there programmer software says: 99 bytes in error.

have you ever seen a problem like this before

any help is greatly appreciated

thanx

Umer

umer

shyam

Sun Nov 23 2008, 10:11PM

Registered Member #2984

Joined: Mon Aug 06 2007, 11:33AM

Posts: 725
Thanked 108 times in 104 posts

are u using the startup.s file ?
try compiling again after removing it from project.

lProgress is not made by early risers or hard workers, but by LAZY people, trying to find easier ways to do the same........

UmerAhmed

Mon Nov 24 2008, 08:23AM

Registered Member #12135

Joined: Tue Nov 11 2008, 11:32AM

Posts: 10
Thanked 0 times in 0 posts

tried after removing it same result
nothing changed,
selecting on-chip does not generate an output
unselecting it produces an output which is not suitable for this processors memory module

thanx for ur help

umer