Summary of I2C bus for 24LC16 For CSS Compiler
This article presents a PIC16F877 project that writes a setpoint to a 24LCxx I2C EEPROM, initializes a 4-bit LCD, and continuously reads and displays the stored setpoint on the LCD. The code configures clocks, timers, I2C, ports, and disables analog/PSP functionality.
Parts used in the PIC16F877 EEPROM Read Project:
- PIC16F877 microcontroller
- 4-bit LCD module (HD44780-compatible)
- 24LCxx I2C EEPROM
- 4 MHz crystal oscillator
- Pull-up resistors for I2C lines (SDA, SCL)
- Power supply (VCC, GND)
- Wiring/header connections
- Development tools for PIC (compiler, programmer)
#include <16F877.h>
#device adc=8
#FUSES NOWDT ,XT
#use delay(clock=4000000)
#use i2c(Master,Fast,sda=PIN_C4,scl=PIN_C3)
#INCLUDE "LCD_4BIT.C"
#include "I2C_24LCxx.c "
int8 value,setpoint=112;
void main(){
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
set_tris_c(0B10000000); // 1000 0000 PortC
set_tris_d(0B00000000); // 0000 0000 Portd is Output
lcd_init();
Write_eeprom_24LCxx(0x01,setpoint);
lcd_init();
lcd_ROW_COL(1,0); // defind ddram address for put string
lcd_putc(" KCHI_MICRO.PIC");
lcd_ROW_COL(2,0);
lcd_putc("READ EEPROM 24LC");
DELAY_MS(1000);
LCD_CLear();
LCD_INIT();
while (TRUE){
Lcd_row_col(1,0);
Lcd_putc("setpoint=");
value=Read_eeprom_24LCxx(0x01);
hex_bcd(VALUE);
lcd_row_col(1,9);
sent_Lcd();
delay_ms(100);
}
}
- What does the project do?
It writes a setpoint value to a 24LCxx EEPROM and continuously reads and displays that value on a 4-bit LCD. - Which microcontroller is used?
The project uses the PIC16F877 microcontroller. - How is the EEPROM accessed?
The EEPROM is accessed via I2C using the sda=PIN_C4 and scl=PIN_C3 configuration. - What initial setpoint is written to EEPROM?
The code writes a setpoint value of 112 to EEPROM address 0x01. - How is the LCD initialized?
The project initializes a 4-bit LCD using included LCD_4BIT.C functions and calls lcd_init and LCD_INIT. - Are analog inputs enabled?
No, analog inputs are disabled using setup_adc_ports(NO_ANALOGS) and setup_adc(ADC_OFF). - Which port pins are configured as outputs?
Port D is configured as all outputs with set_tris_d(0B00000000); Port C sets bit 7 as input with set_tris_c(0B10000000). - How often is the EEPROM value read and displayed?
The code continuously reads the EEPROM and updates the LCD inside a while(TRUE) loop with a 100 ms delay each iteration.
