DTMF Controlling System using 8051 Microcontroller

This is fully tested code of DTMF Controlling System using 8051 Microcontroller. The connections in the circuit are very simple. Connect outputs of DTMF sensor to PORT0 as follows: D3–P0^3, D2–P0^2, D1–P0^1 and D0–P0^0.

The following code is given as per the kit developed at Vidyasagar Academy. To purchase the kit, contact us. If you are the student of Vidyasagar Academy burn the code in the given kit.

/*
	8051 DTMF Home Automation System
	Created by: Prof. Dattaraj Vidyasagar 
	for Vidyasagar Academy, Akola
	Website: http://localhost/wordpress/
	Date: 26.04.2017
*/

#include <reg51.h>
#include "delay.c"
#define Devices P1 // 4 different devices connected to PORT1
#define DTMF P0 // 4 pins (P0^3 to P0^0) of PORT0 will receive signal form DTMF
int main()
{
P1=0x00;  // this will keep all outputs of PORT1 to 0000 0000 initially
delay(1); // momentary delay
P0=0x00; //  defining all pins of PORT0 as input pins
while(1) // infinite loop
{
delay(10); // perceptible pause to allow 
// starting up the transmitter/receiver modules and dev. board
// Controlling signals for the 8 devices connected to PORT1 i.e. from P1.0 to P1.7
// you can use any number of devices from 1 to 8
	if(DTMF==0x0A) // '0' is pressed on calling mobile
	{
		Devices=0x00; // output of all pins of PORT1 is 0000 0000
		delay(2); 		
	}
	if(DTMF==0x01) // '1' is pressed on calling mobile
	{
		Devices=0x01; // only the device connected to P1^0 will be ON i.e. P1 = 0b 0000 0001
		delay(2); 		
	}
	if(DTMF==0x02) // '2' is pressed on calling mobile
	{
		Devices=0x02; // only the device connected to P1^1 will be ON i.e. P1 = 0b 0000 0010
		delay(2); 		
	}
	if(DTMF==0x03) // '3' is pressed on calling mobile
	{
		Devices=0x04; // only the device connected to P1^2 will be ON i.e. P1 = 0b 0000 0100
		delay(2); 		
	}
	if(DTMF==0x04) // '4' is pressed on calling mobile
	{
		Devices=0x08; // only the device connected to P1^3 will be ON i.e. P1 = 0b 0000 1000
		delay(2); 		
	}
	if(DTMF==0x05) // '5' is pressed on calling mobile
	{
		Devices=0x10; // only the device connected to P1^4 will be ON i.e. P1 = 0b 0001 0000
		delay(2); 		
	}
	if(DTMF==0x06) // '6' is pressed on calling mobile
	{
		Devices=0x20; // only the device connected to P1^5 will be ON i.e. P1 = 0b 0010 0000
		delay(2); 		
	}
	if(DTMF==0x07) // '7' is pressed on calling mobile
	{
		Devices=0x40; // only the device connected to P1^6 will be ON i.e. P1 = 0b 010 0000
		delay(2); 		
	}
	if(DTMF==0x08) // '8' is pressed on calling mobile
	{
		Devices=0x80; // only the device connected to P1^7 will be ON i.e. P1 = 0b 1000 0000
		delay(2); 		
	}
	} // while closed
	} // main closed

Note: Download the file of delay.c mentioned in the above program, from following link and copy it in your project folder.

[download id=”2″]

[download id=”3″]