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Showing posts with label Interfacing. Show all posts
Showing posts with label Interfacing. Show all posts

Temperature controlled Water Pump using PIC16f877A and LM35


Automatic Garden Light And Water Pump



Maybe someone today need everything more easy and effective, included with their garden lamp at home. There are many garden lamp operated manually to turn-on and turn-off. Someone need to turn on in the night and turn off in the morning manually. Garden lamp can not work automatically, when condition is dark garden lamp will turn on and when condition is bright garden lamp will turn off automatically too.

I think it is very important in this day. Someone will not again confuse when they go to leave home who will turn on and turn off garden lamp. To take solution for this problem i think someone can use automatically garden lamp that can work automatically. Garden lamp will turn on when condition is dark, and garden lamp will turn off when condition is bright.

Components
PIC16F877A
This powerful (200 nanosecond instruction execution) yet easy-to-program (only 35 single word instructions) CMOS FLASH-based 8-bit microcontroller packs Microchip's powerful PIC® architecture into an 40- or 44-pin package and is upwards compatible with the PIC16C5X, PIC12CXXX and PIC16C7X devices. The PIC16F877A features 256 bytes of EEPROM data memory, self programming, an ICD, 2 Comparators, 8 channels of 10-bit Analog-to-Digital (A/D) converter, 2 capture/compare/PWM functions, the synchronous serial port can be configured as either 3-wire Serial Peripheral Interface (SPI™) or the 2-wire Inter-Integrated Circuit (I²C™) bus and a Universal Asynchronous Receiver Transmitter (USART). All of these features make it ideal for more advanced level A/D applications in automotive, industrial, appliances and consumer applications.

LDR
LDR (or Light Dependant Resistor, or Photoresistor) is a variable resistor. Light falling on the sensor decreases its resistance.
Output: This module outputs 5v when the sensor receives no light (the circuit is open) and 0v when exposed to bright light (the circuit is closed). When connected to an input on the Arduino using the TinkerKit Shield, you can expect to read values from 0 to 1023.
Module Description: This module features a Light Dependent Resistor, a signal amplifier, the standard TinkerKit 3pin connector, a green LED that signals that the module is correctly powered and a yellow LED whose brightness changes according to the amount of lightness.
This module is a SENSOR. The connector is an OUTPUT which must be connected to one of the INPUT connectors on the TinkerKit Shield.

LM35
Description

The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±¼°C at room temperature and ±¾°C over a full -55 to +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level. The LM35's low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus supplies. As it draws only 60 µA from its supply, it has very low self-heating, less than 0.1°C in still air. The LM35 is rated to operate over a -55° to +150°C temperature range, while the LM35C is rated for a -40° to +110°C range (-10° with improved accuracy). The LM35 series is available packaged in hermetic TO-46 transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface mount small outline package and a plastic TO-220 package.


Program 

#include<htc.h>

void initialize(void)
{
        TRISA0=1;
        TRISA1=1;
ADCS1 = 0; //select Fosc/8
ADCS0 = 1;
ADCON1=0; // A/D port configuration 0
ADFM = 1; //right justified result
ADON=1; // turn on the AD conversion module
}
/* return a 10-bit result */
unsigned int read_adc(unsigned char channel)
{
channel&=0x07; // truncate channel to 3 bits
ADCON0&=0xC5; // clear current channel select
ADCON0|=(channel<<3); // apply the new channel select
DelayMs(10);
ADGO=1; // initiate conversion on the selected channel
while(ADGO)continue;
return(((ADRESH&0x03)<<8)+ADRESL); // return the 10-bit result
}



void main(void)
{
long int temp,pres;
initialize();
while(1)
{
temp =read_adc(0)*((5.0*100.0)/1023.0);
               

if (temp>27)
{
PORTD=0x00;
}
else
{

 

Interfacing Keypad with PIC16F877A in C program using MPLAB X

This tutorial will show you how to read a 4x4 keypad input and write to an alphanumeric LCD interfaced to your PIC micro, it's pretty simple and straight forward.

First create a new project and add a c main file like in the  steps for  Blinking a LED using MPLAB X , PIC16F877A
Components
1.PIC16F877A micro controller
2. 4x4 matrix keypad

initial setup
 supply logic 0 (0V or GND) to all 4 keypad row wires or set the row pins as output
 Supply logic 1 (high voltage) to all 4 keypad coloum wires or set coloums  as input


Steps to read a key from the keypad 
1. Find the Row first, by selecting each row
2. scan the colum  which pressed key is
3 Find the key pressed ,the function findKey() is for this


4. If we have at least one key pressed, then return from keypadread()  will be non zero.






PROGRAM 
#######################################################################
    /*
 * File:   main.c
 * Author: Ebin Ephrem
 
 */


#include<htc.h>

#if defined(WDTE_OFF)
__CONFIG(WDTE_OFF & LVP_OFF);
#elif defined (WDTDIS)
__CONFIG(WDTDIS & LVPDIS);
#endif

char findKey(unsigned int a, unsigned int b);
char readKeyboard();

void main()
{  
   TRISB = 0xF0;

unsigned int re;   
 while(1)
    {
        re=0;
        re= readKeyboard();
    }
}
char readKeyboard()

{
 unsigned int i = 0;
 for(i=0;i<4;i++)
 {
  if(i == 0)
  PORTB = 1;
  else if(i == 1)
  PORTB = 2;
  else if(i == 2)
  PORTB = 4;
  else if(i == 3)
  PORTB = 8;

  if(RB4)
    return findKey(i,0);
  if(RB5)
   return findKey(i,1);
  if(RB6)
   return findKey(i,2);
  if(RB7)
   return findKey(i,3);
 }
 return ' ';
}
char findKey(unsigned int a, unsigned int b) //generating key character 
{

 if(b == 0)
 {
   if(a == 3)
    return '3';
   else if(a == 2)
    return '2';
   else if(a == 1)
    return '1';
   else if(a == 0)
    return '0';
 }
 else if(b == 1)
 {
   if(a == 3)
    return '8';
   else if(a == 2)
    return '7';
   else if(a == 1)
    return '6';
   else if(a == 0)
    return '5';
 }
 else if(b == 2)
 {
   if(a == 3)
    return 'b';
   else if(a == 2)
    return '8';
   else if(a == 1)
    return 'A';
   else if(a == 0)
    return '-';
 }
 else if(b == 3)
 {
   if(a == 3)
    return 'C';
   else if(a == 2)
    return 'U';
   else if(a == 1)
    return 'E';
   else if(a == 0)
    return 'F';
  }
}

######################################################################


you can modify the number of colums and rows for 3x4 keypad , and for the other keypads



 

Interfacing LCD with PIC16F877A in MPLAB X

Most of the embedded projects have some user interfaces, most of them uses LCD displays for output
Here we are going to see how to interface an 16x2 LCD with PIC16F877A
First Create a MPLAB X project as in the steps for  Blinking a LED using MPLAB X , PIC16F877A


Components
1.PIC16F877A micro controller
2. 2x16 LCD Display




Most of the  LCD have 16 Pins
3 Control Pins
8 Data Pins
4 Power Pins
Steps For Interfacing LCD 
1. Take two ports make one as input and other as output by loading 1 to TRIS register and 0 to TRIS respectively
             Step 1: Initialize the LCD.
          The LCD must be initialized the by following pre-defined commands of character LCD.
·         0x38, to configure the LCD for 2-line, 5x7 font and 8-bit operation mode
·         0x0C, for Display On and Cursor Off
·         0x01, to Clear Display screen
·         0x06, to increment cursor
·         0x80, to set cursor position at first block of the first line of LCD.

Step 2: Send the commands to LCD.
·         Send the command byte to the port connected to LCD data pins
·         RS=0, to select command register of LCD
·         RW=0, to set the LCD in writing mode
·         EN=1, a high to low pulse to latch command instruction
·         Delay of 1ms
·         EN=0


Step 3: Send data to LCD.

·         Send data at the port which connected to LCD data pins

·         RS=1, register select to select data register of LCD
·         RW=0, this set the LCD in writing mode
·         EN=1, a high to low pulse to latch data
·         Delay of 1ms
·         EN=0

Step 4: Display character on LCD.

The functions lcdcmd() and lcddata() are user-defined functions. They are used to send a character (E in this case) to be displayed on LCD.

LCD_CMD(0x38);             // send command 0x38 to LCD
LCD_DAT(‘E’);                // send character E to LCD

schematic diagram :




THE PROGRAM IS AVAILABLE ON GITHUB : https://github.com/ebine/lcd-interface-pic16f877a


# include<htc.h>

#if defined(WDTE_OFF)
__CONFIG(WDTE_OFF & LVP_OFF);
#elif defined (WDTDIS)
__CONFIG(WDTDIS & LVPDIS);
#endif

#define RS RE0
#define RW RE1
#define EN RE2
#define DATA PORTB

void LCD_CMD(unsigned int value);
void LCD_DAT(unsigned int value);
void delay();


int main(void)
{
    ADCON0 = 0x00;//Disable ADC ports
    ADCON1 = 0x06;//Disable ADC ports

    TRISE =0x00;
    TRISB =0x00;
    //DATA=0x01;
    LCD_CMD(0x01);
    delay ();
    LCD_CMD(0x38);
    delay ();
    LCD_CMD(0x0F);
    delay ();
   // LCD_CMD(0x07);
    delay();
    LCD_CMD(0x06);
    delay ();
    LCD_CMD(0x0c);
    delay ();


    LCD_CMD(0x80);
    delay ();

    //DATA='A';
    LCD_DAT('S');
    LCD_DAT('E');
    LCD_DAT('R');
    LCD_DAT('V');
    LCD_DAT('4');
    LCD_DAT('U');

    LCD_CMD(0x80);
     while(1);
    return (0);

}

void LCD_CMD(unsigned int value)
{
    DATA =value;
    RS=0;
    RW=0;
    EN=1;
    delay ();
    EN=0;
    delay ();
 }

void LCD_DAT(unsigned int value)
{
    DATA=value;
    RS=1;
    RW=0;
    EN=1;
    delay ();
    EN=0;
    delay();

}

void delay(void)
{
    int counter = 0;
    for (counter = 0; counter<10000; counter++) {
        ;
    }
}


 
 
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