Interfacing ESP8266 With PIC16F877A Microcontroller

#define _XTAL_FREQ 20000000

#define RS RD2 #define EN RD3 #define D4 RD4 #define D5 RD5 #define D6 RD6 #define D7 RD7

#include <xc.h> #include “esp8266_functions.h”

#pragma config FOSC = HS        // Oscillator Selection bits (HS oscillator) #pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled) #pragma config PWRTE = OFF       // Power-up Timer Enable bit (PWRT enabled) #pragma config BOREN = ON       // Brown-out Reset Enable bit (BOR enabled) #pragma config LVP = OFF        // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming) #pragma config CPD = OFF        // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off) #pragma config WRT = OFF        // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control) #pragma config CP = OFF         // Flash Program Memory Code Protection bit (Code protection off)

//****LCD Functions Developed by Circuit Digest.***/// void Lcd_SetBit(char data_bit) //Based on the Hex value Set the Bits of the Data Lines { if(data_bit& 1) D4 = 1; else D4 = 0;

if(data_bit& 2) D5 = 1; else D5 = 0;

if(data_bit& 4) D6 = 1; else D6 = 0;

if(data_bit& 8) D7 = 1; else D7 = 0; }

void Lcd_Cmd(char a) { RS = 0; Lcd_SetBit(a); //Incoming Hex value EN  = 1; __delay_ms(4); EN  = 0; }

Lcd_Clear() { Lcd_Cmd(0); //Clear the LCD Lcd_Cmd(1); //Move the curser to first position }

void Lcd_Set_Cursor(char a, char b) { char temp,z,y; if(a== 1) { temp = 0x80 + b – 1; //80H is used to move the curser z = temp>>4; //Lower 8-bits y = temp & 0x0F; //Upper 8-bits Lcd_Cmd(z); //Set Row Lcd_Cmd(y); //Set Column } else if(a== 2) { temp = 0xC0 + b – 1; z = temp>>4; //Lower 8-bits y = temp & 0x0F; //Upper 8-bits Lcd_Cmd(z); //Set Row Lcd_Cmd(y); //Set Column } }

void Lcd_Start() { Lcd_SetBit(0x00); for(int i=1065244; i<=0; i–)  NOP(); Lcd_Cmd(0x03); __delay_ms(5); Lcd_Cmd(0x03); __delay_ms(11); Lcd_Cmd(0x03); Lcd_Cmd(0x02); //02H is used for Return home -> Clears the RAM and initializes the LCD Lcd_Cmd(0x02); //02H is used for Return home -> Clears the RAM and initializes the LCD Lcd_Cmd(0x08); //Select Row 1 Lcd_Cmd(0x00); //Clear Row 1 Display Lcd_Cmd(0x0C); //Select Row 2 Lcd_Cmd(0x00); //Clear Row 2 Display Lcd_Cmd(0x06); }

void Lcd_Print_Char(char data)  //Send 8-bits through 4-bit mode { char Lower_Nibble,Upper_Nibble; Lower_Nibble = data&0x0F; Upper_Nibble = data&0xF0; RS = 1;             // => RS = 1 Lcd_SetBit(Upper_Nibble>>4);             //Send upper half by shifting by 4 EN = 1; for(int i=2130483; i<=0; i–)  NOP(); EN = 0; Lcd_SetBit(Lower_Nibble); //Send Lower half EN = 1; for(int i=2130483; i<=0; i–)  NOP(); EN = 0; }

void Lcd_Print_String(char *a) { int i; for(i=0;a[i]!=’\0′;i++) Lcd_Print_Char(a[i]);  //Split the string using pointers and call the Char function } //***End of LCD functions***//

void main() { TRISD = 0x00; Lcd_Start(); Initialize_ESP8266() ; Lcd_Set_Cursor(1,1); Lcd_Print_String(“Circuit Digest”); Lcd_Set_Cursor(2,1); Lcd_Print_String(“ESP5266 with PIC”); __delay_ms(1500); Lcd_Clear();

/*Check if the ESP_PIC communication is successful*/ do { Lcd_Set_Cursor(1,1); Lcd_Print_String(“ESP not found”); }while (!esp8266_isStarted()); //wait till the ESP send back “OK” Lcd_Set_Cursor(1,1); Lcd_Print_String(“ESP is connected”); __delay_ms(1500); Lcd_Clear(); /*Yes ESP communication successful*/

/*Put the module in Soft AP  mode*/ esp8266_mode(2); Lcd_Set_Cursor(1,1); Lcd_Print_String(“ESP set as AP”); __delay_ms(1500); Lcd_Clear(); /*Module set as AP */

/*Configure the AP name and Password*/ esp8266_config_softAP(“CircuitDigest”,”619007123″); Lcd_Set_Cursor(1,1); Lcd_Print_String(“AP configured”); __delay_ms(1500); /*AP configured*/

while(1) { //do nothing }

}