PIC16F684 : store temperature data inside EEPROM in c

[lizzy]

hello, i'm really new in this embedded stuff. can someone help/ teach me how to code it? that is i have to save/store temperature data into EEPROM in 512 cycles and every cycle is 30 mins. please i really 0 input about this program

 

[rajudp]

pic16f684 is having only 256 bytes of eeprom, you have to go for a higher end processor or by using an external eeprom like 24xx

 

[lizzy]

sorry my mistake. like what u said js store 256 bytes. can u g guide me to build my program rajudp?

 

[rajudp]

how you are reading temperature, and what is the range?

 

[lizzy]

if it is possible the range is more than 200degree. (if i can find the suitable thermistor) but for now i js set it in normal temperature between 0 and 140 farenheit. and i hope it can save data every 30 mins

 

[rajudp]

look the links you will get an idea

**broken link removed**
http://quozl.netrek.org/ts/
**broken link removed**


you can use LM 35 pt100 or any thermistor for this application ,

the microcontroller is having 10 bit ADC , and yoy have to use it as 8bit to store 256 values.

do you want to store only temperature or with time stamp

 

[lizzy]

yes i want to store the data with time stamp. but i don't need to display the data in any lcd. i js pick the data inside pic connected to pickit2.
i already search around but still i really have no idea. j assume that i have nothing about this coding. please help me. how to code it.

 

[rajudp]

i you want it with time stamp you have to use external eeprom since you need more memory

Added after 3 minutes:

check this link you cam use your pic here
https://www.best-microcontroller-projects.com/eeprom.html

 

[lizzy]

then can u help me in this? oh please.

 

[lizzy]

this is the code. how to write EEPROM inside it?

#include <pic.h>

#define	DIGIT1	RA0	
#define	DIGIT2	RA1	
#define 	DIGIT3	RA2	
#define	ON			0
#define	OFF		1

/* 
RA5 - Segment a
RC5 - Segment b
RC4 - Segment c
RC3 - Segment d
RC2 - Segment e
RC1 - Segment f
RC0 - Segment g

RA4 - Thermistor
*/

__CONFIG(INTIO & WDTDIS & PWRTEN & MCLRDIS & UNPROTECT \
  & UNPROTECT & BORDIS & IESODIS & FCMDIS);
  
  
const char LEDDigit[10] = {
    0b0000001,                  //  Digit Zero
    0b1001111,                  //  Digit One
    0b0010010,                  //  Digit Two
    0b0000110,                  //  Digit Three
    0b1001100,                  //  Digit Four
    0b0100100,                  //  Digit Five
    0b0100000,                  //  Digit Six
    0b0001111,                  //  Digit Seven
    0b0000000,                  //  Digit Eight
    0b0000100};                 //  Digit Nine
    
  
int Temperature, TempDigit, DisplayPos, D1, j;
int ADCState;

int i, j, d, t, temp;
main()
{
	///////////  INIT  ////////////
	
	PORTA = 0;
	PORTC = 0;
	TRISA = 0b010000;      		//  All Bits of PORTA are Outputs except RA4
   TRISC = 0;           		//  All Bits of PORTC are Outputs
   
   CMCON0 = 7;                //  Turn off Comparators
   ANSEL = 1 << 4;            //  RA4 is ADC input
   ADCON0 = 0b00001101;			//  Left justify, Use Vdd, Channel 4 (AN3), Do not start, Turn on
   ADCON1 = 0b00010000;			//  run oscillatr as 8 x prescalar
   
   DisplayPos = 0;
   j = 0;
   Temperature = 0;
   ADCState = 0;

  
   ////  MAIN LOOP  ////
   
   while(1)
   {
	   ///////////  DISPLAY READOUT  ///////////
	   
	   DIGIT1 = OFF;
	   DIGIT2 = OFF;
	   DIGIT3 = OFF;
	   
		if(DisplayPos == 0)									//Light 1st segment
		{
			TempDigit = Temperature % 10;					//Just get "1"s place
			RA5 = LEDDigit[TempDigit] >> 6;				//Turn on digit
			PORTC = LEDDigit[TempDigit];
			DIGIT3 = ON;
			for(D1=0;D1<414;D1++);							//Delay for 7ms
			
		}else if(DisplayPos == 1)							//Light 2nd segment
		{
			TempDigit = Temperature % 100;				//Just get "10"s place (strip off "100"s place)
			TempDigit = TempDigit / 10;					//   and convert to "1"s place
			RA5 = LEDDigit[TempDigit] >> 6;				//Turn on digit
			PORTC = LEDDigit[TempDigit];
			DIGIT2 = ON;
			for(D1=0;D1<400;D1++);							//Delay for 7ms
		}else														//Light 3rd segment
		{	
			TempDigit = Temperature / 100;				//Just get "100"s place
			RA5 = LEDDigit[TempDigit] >> 6;				//Turn on digit
			PORTC = LEDDigit[TempDigit];
			DIGIT1 = ON;
			for(D1=0;D1<400;D1++);							//Delay for 7ms
		}

		DisplayPos = (DisplayPos + 1) % 3;				//Next segment
		
		
		j++;
		if(j == 50)												//Time to update temp?
		{
			j = 0;
		
			switch(ADCState)
			{
				case 0:						//Start ADC operation
					GODONE = 1;
					ADCState = 1;
					break;
				case 1:
					ADCState = 0;
					Temperature = ADRESH - 82;
					break;
			}
		}
	}
}

 

[btbass]

If you look at the file 'Pic.h' you will see that Hi-Tech includes eeprom read and write macros and functions in it's libraries.

The function prototypes for reading and writing eeprom are defined like so:

/* library function versions */
extern void eeprom_write(unsigned char addr, unsigned char value);
extern unsigned char eeprom_read(unsigned char addr);

You have already included <pic.h> so these functions are visible.
So to read and write eeprom, just use the library functions.

 

[rajudp]

you can store ADRESH value, but here you are monitoring in every 7ms