[SOLVED] project in distress..

[jayanth.devarayanadurga]

 unsigned int LastTemp

defines LastTemp variable as unsigned int. So, you cannot store values less than 0 in it. In

 signed int LastTemp

you can store negative values. For range of values for different data types see c18 manual.

Have you tested the LCD code you are using before? Does it work?

 

[InNeedOfHelp]

i took a look at the C18 Manual..
do you think we can use

#include <capture.h>

?

- - - Updated - - -

or perhaps use

putcUSART

 

[jayanth.devarayanadurga]

To use putcUSART you have to use OpenUSART() function to start serial communication. Then if you use putcUSART it will print on Virtual Terminal. If you have any other project with LCD code working then post it.

 

[InNeedOfHelp]

First attached file is Voltage Test.rar.. using ADC..

Second Attached file is my original file , i using the lib original xlcd.h file

i got this error . no matter how i solve also cannot solve ...
Error - could not find definition of symbol 'DelayFor18TCY' in file 'busyxlcd.o'.

 

[jayanth.devarayanadurga]

Which of the 2 files is working? Mention the MCU used in that project and also the Fosc.

 

[InNeedOfHelp]

Voltage Test.rar is the one that is displaying strings...
Both are using PIC18F4520 and are using internal osc

 

[jayanth.devarayanadurga]

Good. I tested Voltage Test.rar and it displays on LCD. Just use the code in Voltage Test.rar in you I2C project code. It uses the same PIC and same connections.

 

[InNeedOfHelp]

#include<p18f4520.h>
#include "picdem2lcd.h"
#include<i2c.h>
#include<delays.h>
#include <stdio.h>

#pragma config OSC = INTIO67
#pragma config WDT = OFF    //Turn off watchdog timer
#pragma config LVP = OFF    //Turn off low voltage program
#pragma config DEBUG = OFF  //Turn off debug mode

void initLCD(void);
//Start Of Main Function//
void main()
{
	unsigned int LastTemp = 0;
	TRISB = 0x00;
	PORTB = 0x00;
	TRISD = 0x00;
	PORTD = 0x00;
	SSPSTAT = 0x80; //Disable SMBus & Slew Rate Control 
	SSPCON1 = 0x28; //Enable MSSP Master 
	SSPADD = 19; //Internal Crystal 8MHz, Standard Mode for I2C 100kHz : Fosc/4*(SSPADD+1) 
	SSPCON2 = 0x00; //Clear MSSP Conrol Bits 
	
	while(1)
	{
		IdleI2C(); // ensure module is idle 
		StartI2C(); // initiate START condition 
		while ( SSPCON2bits.SEN ); // wait until start condition is over 
		Delay10TCYx(10);
		WriteI2C( 0b10011010 ); // Send TC74 address (Write; LSB=0 10011010) 
		IdleI2C(); // ensure module is idle 
		WriteI2C( 0 ); // Select Temperature Register 
		IdleI2C(); // ensure module is idle 
		RestartI2C(); // generate I2C bus restart condition 
		while ( SSPCON2bits.RSEN ); // wait until re-start condition is over 
		WriteI2C( 0b10011011); // Send TC74 address (Read; LSB=1  10011011) 
		IdleI2C(); // ensure module is idle 
		ReadI2C(); // read in the temp 
		NotAckI2C(); // send not ACK condition 
		while ( SSPCON2bits.ACKEN ); // wait until ACK sequence is over 
		StopI2C(); // send STOP condition 
		while ( SSPCON2bits.PEN ); // wait until stop condition is over 
		LastTemp = SSPBUF; // LastTemp is a Global unsigned char
		initLCD();
		putrsLCD((const far rom char * ) "Hello");
	

	} 
} 
void initLCD(void)
{
	putrsLCD((const far rom char*)"Initializing LCD...");
	TRISD = 0x00;       //Set port D as outputs initially for LCD
	PORTDbits.RD7 = 1;  //Power On LCD
	OpenXLCD(FOUR_BIT & LINES_5X7);
	while(BusyXLCD());
	WriteCmdXLCD(DON & CURSOR_OFF & BLINK_OFF);
	printf((const far rom char*)"done.\r\n");
}

i followed the same method as i did before but it still couldnt display

 

[jayanth.devarayanadurga]

See this simulation video. It is displaying and i2c is working but the display is moving. You are not getting the display because you have not called initLCD() before main() function.

 

[InNeedOfHelp]

because it is a while loop, so the steps keeps repeating ?

 

[jayanth.devarayanadurga]

Ok. I got the I2C value displayed. See it shows 27 for 27 degrees. We have to stop the moving. Don't worry we will fix it. No not because of the while loop.

 

[InNeedOfHelp]

hmm, perhaps try a delay 1s function ?

 

[jayanth.devarayanadurga]

No. The problem is something else.

 

[InNeedOfHelp]

how do you tell?

 

[jayanth.devarayanadurga]

Does delay shifts the characters in LCD?

 

[InNeedOfHelp]

ic... i remember when i was doing C++ program.
there was a function call leave a line

printf("/n");

or is it /r . i am not very sure of it already

 

[jayanth.devarayanadurga]

It is printf("\r\n");


Edit: See it is working.

 

[InNeedOfHelp]

Hey jayanth ,thank you so much , managed to complete it.

 

[InNeedOfHelp]

jayanth, if i were to draw a flowchart for my temperature program, how am i going to do it ?

 

[jayanth.devarayanadurga]

Do you want to write a detailed flowchart including I2C routines or just a simple flowchart?