im new to programming and having problems writing to eeprom. The code below is to set freq. value when a push button is pressed and then each time the freq. value is greater than the set value the selected port goes high. The program works fine but each time i total power away from the pic 16f887 it looses the setting can anyone please assist.
Thanking you in advance
Ivan
//* Copyright:
//IVAN NAIR
//* Description:
//The incoming frequency to be measured must be
//connected to PORTC. (T1CKI) pin.
//* Test configuration:
//MCU: PIC16F887
//Oscillator: HS, 20.0000 MHz
// out put relay connected to port D2
//******************************************************************************/
// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections
#include"BUILT_IN.H"
EEPROM_WRITE(set_freq);
EEPROM_READ(set_freq);
unsigned char int_sec_count; // used to count ints/second
unsigned char new_second; // is set once per second
unsigned char tchar; // text char used in LCD display numbers
unsigned int freq; // 0-65000, holds freq value to display integer hertz
unsigned int set_freq; // set freq when but is pressed
unsigned long rpm; // holds RPM for calcs AND display RPM= Revolution pr minute
char txt[12]; // used to display number string
char sec_count;
//-----------------------------------------------------------------------------
void interrupt()
{
// this is TMR2 overflow interrupt
int_sec_count--;
if(!int_sec_count) // if reached 1 second!
{
// get the TMR1 count!
T1CON = 0; // TMR1 OFF
freq = ((TMR1H <<
+ (TMR1L)); // put TMR1 16bit value in freq TMR1L = 0; // clear TMR1
TMR1H = 0;
T1CON = 0b00000011; // TMR1 back ON again
// that's everything done for this second
new_second++;
int_sec_count = 125; // load ready to generate another second
}
TMR2IF_bit = 0; // Clear TMR2IF before exit
}
//-----------------------------------------------------------------------------//
void main()
{
//-------------------------------------------------------
// setup PIC 16F887 registers
ANSEL = 0; // Configure AN pins as digital
ANSELH = 0;
C1ON_bit = 0; // Disable comparators
C2ON_bit = 0;
TRISC = 0b00000001; // PORTC.F0 = input from freq signal
PORTA = 0b11111111;
TRISA = 0b11111111;
TRISB = 0; //
PORTB = 0xFF; //
TRISB = 0xff; //
PORTD = 0b00000000;
TRISD = 0b00000000;
EEPROM_READ;
//-------------------------------------------------------
// show startup message
//Lcd_Config(0); // Initialize Lcd over SPI interface
Lcd_Init();
Lcd_Cmd(_LCD_CLEAR); // Clear display
Lcd_Cmd(_LCD_CURSOR_OFF); // Turn cursor off
Lcd_Out(1,2, "FREQUENCY"); // display startup text to Lcd
Lcd_Out(2,2, "SPEED");
Delay_1sec();
Delay_1sec();
// clear LCD again before main
Lcd_Cmd(_LCD_CLEAR);
//-------------------------------------------------------
// setup the timers for frequency counting
// setup TMR1
T1CON = 0b00000011; // TMR1 ON, external clock pulse on PORTC.F0
// setup TMR2 and enable TMR2 int
T2CON = 0b00011111; // TMR2 ON, 8MHz xtal, 16:4:1 = 31250 Hz (Timer 2 prescaler settings)
PR2 = 250; // TMR2 int is 31250 / 250 = 125 ints/sec
PIE1.TMR2IE = 1; // TMR2 interrupt is on
INTCON = 0b11000000; // GIE=ON, PIE=ON
// load variables ready to run
int_sec_count = 125;
//-------------------------------------------------------
// now do the main run loop
while(1)
{
// safe limit freq at 65 kHz
if(freq > 65000) freq =65000;
// everytime we reach a second, calculate and display freq
if(new_second)
{
new_second = 0;
freq = freq;
// display freq as "xxxxx Hz"
WordToStr(freq,txt);
Lcd_Out(1,8,txt);
Lcd_Out(1,14,"Hz");
// calc RPM from freq
rpm = (freq / 1.4); // for speed divide by 1.4* for rpm * 3.4 *****************
// format rpm to display as "xxxxxxx RPM"
LongToStr(rpm,txt); // get the rpm as a string
Lcd_Out(2,2,txt); // and display RPM!
Lcd_Out(2,14,"SPEED");
// format to lock speed & rpms
if (Button(&portA,2,0,1))
set_freq = freq;
EEPROM_WRITE(Lo,set_freq);
EEPROM_WRITE(Hi,set_freq);
EEPROM_READ(freq>set_freq)
(PORTD.RD2 = 1);
if(freq<set_freq)
(PORTD.RD2 = 0);
}
}
}
