Need some input output help, AND questions about LCD

[AA]

Well, im quite new to pic's and to this compilator..

Anyway, im using 18F452 and im trying to make it react to an input on Pin_a1 by flashing a LED on B2, and while it doesnt have the input, i would like it to flash B1. But now when i start it, B2 flashes for hmm maybe a minute then B1 starts to flash, it reacts on the input but B2 doesnt stop to flash when i remove it (the input on A1), after a while it stops and B1 begins to flash again.

MY CODE
-----------------------------
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=12000000)
#define sensor_pin PIN_A0
#define LED_PIN1 PIN_B1
#define LED_PIN2 PIN_B2


void init()
{
SETUP_ADC_PORTS(NO_ANALOGS);
set_tris_b(0x00); // RB = OUTPUT
output_b(0x00);
set_tris_a(0xFF); //RA = INPUT
}

void hitta()
{
if(input(sensor_pin) == 0) {
output_high(LED_PIN1);
delay_ms(100);
output_low(LED_PIN1);
delay_ms(100);
}
if(input(sensor_pin) == 1){
output_high(LED_PIN2);
delay_ms(100);
output_low(LED_PIN2);
delay_ms(100);
}

}

void main() //Main program start here
{
init();
while(1){
hitta();
}
}

---------

[PhilWinder]

code seems ok, whenever i get anything wrong, its usually the hardware, so give it a good check over.

firstly check that you have pullups on the inputs, sounds like its floating.
then check osc value, cap values and mclr, but it wouldnt work at all if that was disconnected.

other than that, you could try something a bit simpler, like first getting the led to flash, then get it to turn on when you hit a button, then put the two together to make this.

phil

[Guest]

I made it work with this code instead, using interuppts:

MY CODE
------------------------
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=12000000)

#int_ext //Set external interrupt on pin RB0
void ISR()
{
output_low(pin_b4); // when RB0 is high turn off LED
delay_ms(1000);
} // End Interrupt routineb3

#int_ext2
void ISR2()
{
output_high(pin_b4); //when RB1 is high turn on led
delay_ms(1000);
}

void init()
{
output_b(0x00);
set_tris_b(0x03); // Set RB0, RB1 to input, RB2-7 output

ext_int_edge(1,L_TO_H); // init interrupt triggering for button press
ext_int_edge(2,H_TO_L);
enable_interrupts(INT_EXT);
enable_interrupts(INT_EXT2);
enable_interrupts(GLOBAL);
}
void hitta()
{
while (1) // keep LED flashing
{
output_high(PIN_b4);
delay_ms(100);
output_low(PIN_b4);
delay_ms(100);
}
}
void main() //Main program start here
{
init();
hitta();
}
------------------

Now im wondering if i can run a LCD (www.farnell.com/datasheets/52032.pdf) 16x2 along with this code, im not so good at this yet but what i can understand the pic.c wants to use port B to work with the LCD but my port B is busy with handling the interrupts.

Thanks

[AA]

oops forgot to log in

[PCM programmer]

[AA]

Thanks for the reply!

[PCM programmer]

No, when a LCD is used in 4-bit mode, you always use the upper 4 bits
on the LCD data bus. That's DB4-DB7.

To see how it's done on the PicDem2 Plus board, go to this page
and down at the bottom, download the User's Guide.
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en010072&part=DM163022

Then in that document, go to Appendix A, Section A.13 Board Layout
and Schematics, and then Figure A-3.

At the top of the page it shows the LCD. They are taking DB4 on the
LCD to pin RD0 on the PIC. Then DB5 to RD1, etc. In other words,
the upper 4 bits on the LCD go to the lower 4 bits on Port D.

If it was me, I would have used the upper 4 bits on Port D, just because
then the bit positions between the PIC and the LCD would have been
one-to-one. It would have been easier.