i need help on LED programming

[love_hina]

hi to all..i need urgent help on programmin PIC18f252. using visual basic, user can enter the data to turn on the 7 LED lights on the board. eg. 1 will light up 1st light...etc. the problem is i do not know how to do it..i am a newbie in this and have try different ways but it doesn't work. i'm using MPLAB IDE v6.40.. pls help me..thanz a lot..

[Haplo]

Which part of the project is giving you trouble? Getting the PIC to talk to VB? Or flashing the LEDs?
Give us more information, and post your code.

[love_hina]

i was not able to compile the program. it seems to have error...


#include <p18f252.h>
#include <timers.h>

#define NUMBER_OF_LEDS 7

void timer_isr (void);

static unsigned char s_count = 0;

#pragma code low_vector=0x18
void low_interrupt (void)
{
_asm GOTO timer_isr _endasm
}

#pragma code

#pragma interruptlow timer_isr save=PROD

void timer_isr (void)
{
static unsigned char led_display = 0;


INTCONbits.TMR0IF = 0;

s_count = s_count % (NUMBER_OF_LEDS + 1);

led_display = (1 << s_count++) - 1;

PORTB = led_display;
}

void
main (void)
{
TRISB = 0;
PORTB = 0;

OpenTimer0 (TIMER_INT_ON & T0_SOURCE_INT & T0_16BIT);

INTCONbits.GIE = 1;

while (1)
{
}
}

[Mark]

Well your biggest problem if you are using CCS is that it appears the program was written for the Microchip C18 compiler

[love_hina]

yap..i got the program as i did not know wat to write..so i used it as a guide. my teacher in charge told me to do this.. right now i'm trying to modify but i dunno where to start..

[SherpaDoug]

Start REALLY simple!
Try a program that just blinks one LED. Something like:

Initialize ports
while (1) {
toggle LED
delay 1 second
}

Translating pseudo code to runnable C is left as an excercise for the student ;-)

Once that works try lighting a string of LEDS in sequence.
Next blink an LED whenever anything comes in the serial port.
Then try your original programming problem.
_________________
The search for better is endless. Instead simply find very good and get the job done.

[Mark]

You will have to look at the CCS manual. There are some samples there that will show you how to setup the fuses. Take a look at the interrupts. CCS does this much simpler. Look at the setup_timer functions instead of the C18 open_timer fuctions.

[SherpaDoug]

For his simple problem I would suggest polling might be simpler than interrupts. Just keep polling kbhit() then use getch() when kbhit() returns true.
_________________
The search for better is endless. Instead simply find very good and get the job done.

[love_hina]

thanz a lot..i will go try it out first.

[love_hina]

does anyone out there have the source code for lighting up LED?or u know of any webby tt has examples??i'm stuck on my project and need some sample..thanz a lot...

my program consists of lighting up LED by taking the input from what the user has key in from Visual basic. if the user key in 0,none of the LED will light up, if he key in 15, alternate lights will light up.. if reset button is pushed,all the lights will light up. i'm using RS232 for the link to visual basic and now i'm compiling for microcomputer. if u know of any web,pls help me..as time is pushing and i'm still having problems with my board..
thanz a lot...

[Mark]

You didn't describe you circuit or tell us was demo board you are using. Also post you code that you are trying. The previous code is not an example of what you are trying to do. People will help here but they are not going to do the work for you.

[love_hina]

i'm jus asking if anyone has code sample for me to refer to. the board is done by me..7 LEDs , pic18f252, max232, RJ45 and db9con.... plus a few risistors and capacitors

[dyeatman]

ChingBs post immediatly after mine made mine irrellevant so I deleted it...

Oh Well...

[chingB]

[love_hina]

thanz a lot to both of you..hee..but i'm still blur..i go test it out first then i ask you more about the code..thanz a lot....