DTMF based Home Automation
Content
Synopsis
DTMF Based Home Automation
Name of the Scholars:
Mr. Nirmaljit Singh Pannu Mr. Rohtaj Mehta Mr. Shivtej Singh Mr. Shubham Kondal 9780609747 9803279817 9646033035 9878083807
Under the supervision of:
Ms. Kiranbir Kaur Mr. Hartej Singh Dadhwal Mr. Paramjit Singh Prof. Y.S.Randhawa (HOD) (Asstt. Professor) (Asstt. Professor) (Asstt. Professor) (Associate Professor)
(GIMET, Amritsar)
Table of Contents
1. Introduction of the Project. 2. Working of this home automation project.
3. Components required for home automation
4. Block Diagram and circuit configuration of the Project. 5. Applications of the Project. 6. Merits & Demerits of the Project. 7. Future scope of the Project.
1. Introduction of the Project.
• In today’s world remote control over the electronic appliances is of the utmost importance. • In today’s era communication system is bringing the world closer and telecommunication is one of the inevitable parts and serves the best medium to control the appliances. • This project employs the same technique for controlling various devices through the telephone line. • The basic heart of this project is the DTMF tone. • One can access this unit even when he/she is not present at the place where the system is installed. • Any DTMF telephone set or hand-held tone dialer may be used to send commands to the switching unit. • The switching unit is capable of controlling mains, powered loads with the aid of commands received via a telephone.
2. Working of this home automation project.
• Our project uses M-8870 DTMF decoder IC which decodes tone generated by the keypad of cell phone. • When you press any key on your mobile phone while call is in progress, the other person will hear some tones corresponding to the keys pressed. These tones are based on the DTMF (Dual Tone Multi Frequency) technology.
• Data is transmitted as pairs of tones. The receiver detects the valid frequency pair and gives the appropriate BCD code as the output of the DTMF decoder IC. • See the figure below. Cut the microphone wire and you will be able to see 4 wires. Among these wires you need only 2 wires- Ground and Right as shown in figure.
• Select the right wire and connect it as the DTMF input to the decoder circuit. Ground should be connected to common ground of our circuit. • The signals from the microphone wire are processed by the DTMF decoder IC which generates the equivalent binary sequence as a parallel output of Q1, Q2, Q3, and Q4.
Table showing DTMF Low and High frequency tones and decoded output
Button 1 2 3 4 5 6 7 8 9 Low DTMF frequency (Hz) 697 697 697 770 770 770 852 852 852 High DTMF frequency (Hz) 1209 1336 1477 1209 1336 1477 1209 1336 1477 Binary coded output Q1 0 0 0 0 0 0 0 1 1 Q2 0 0 0 1 1 1 1 0 0 Q3 0 1 1 0 0 1 1 0 0 Q4 1 0 1 0 1 0 1 0 1
0 * #
941 941 941
1336 1209 1477
1 1 1
0 0 1
1 1 0
0 1 0
• The output Q4 from the DTMF decoder IC is fed to the clock input of IC 7474 D flip flop which acts as a buffer to the output from M8870 DTMF decoder IC. • IC7474 is configured as Toggling mode that is if it gets a clock pulse the output of this IC (Pin 5) sets to high and further clock pulse resets back the IC. (The outputs toggle whenever a key is pressed). • When we press and release any of the keys among 1, 3, 5, 7, 9 and *, the DTMF decoder IC generates a high pulse which acts as a clock to our flip flop and sets the output flip flop to high. • The output of flip flop is connected to the relay driver circuit via 100Ω resistor; this output energizes the relay coil through BC547 transistor and turns ON the bulb that is connected at the normally open terminal of relay circuit.
3. Components required for home automation:
• • • • •
• • • • • • • •
2 MT 8870 DTMF IC (1) 5 2 LINE LCD DISPLAY (1) 7 DIODE (1) 8 PUSH BUTTON (1) 9 LEDS (4) Regulated power supply DTMF decoder IC (M-8870) Resistors (100Ω; 100kΩ; 70kΩ; 390kΩ) Capacitors (0.1µFx 2) Crystal oscillator (3.579545MHz) IC 7474 D flip flop BC547 Transistor 6V relay
4. Block Diagram and circuit configuration of the Project.
• This circuit makes use of DTMF (Dual Tone Multi Frequency) technique.
Block Diagram
Circuit configuration of the Project:
5. Applications of the Project.
• Wide range of applications in various fields • Telephone answering machine • Industrial applications • Office applications • Institutional applications • Telephone answering machine • Interactive voice response system(IVRS)
6. Merits & Demerits of the Project. Merits
• • • • • • • •
No distance limitation. Instant switching without any delay. Use less components and power consumption is low. Its cost is very less. It cannot be misused unless any other person knows the code.
Demerits
The unit cannot be accessed when the phone is dead. It is only used on phones having DTMF dialing facilities. The wiring becomes complex and costly.
7. Future of This Project.
• • • • Data logging facility can be included. Computer can be interfaced. System reliability can be improved. Wide spread of automation.
DTMF Based Home Automation
Name of the Scholars:
Mr. Nirmaljit Singh Pannu Mr. Rohtaj Mehta Mr. Shivtej Singh Mr. Shubham Kondal 9780609747 9803279817 9646033035 9878083807
Under the supervision of:
Ms. Kiranbir Kaur Mr. Hartej Singh Dadhwal Mr. Paramjit Singh Prof. Y.S.Randhawa (HOD) (Asstt. Professor) (Asstt. Professor) (Asstt. Professor) (Associate Professor)
(GIMET, Amritsar)
Table of Contents
1. Introduction of the Project. 2. Working of this home automation project.
3. Components required for home automation
4. Block Diagram and circuit configuration of the Project. 5. Applications of the Project. 6. Merits & Demerits of the Project. 7. Future scope of the Project.
1. Introduction of the Project.
• In today’s world remote control over the electronic appliances is of the utmost importance. • In today’s era communication system is bringing the world closer and telecommunication is one of the inevitable parts and serves the best medium to control the appliances. • This project employs the same technique for controlling various devices through the telephone line. • The basic heart of this project is the DTMF tone. • One can access this unit even when he/she is not present at the place where the system is installed. • Any DTMF telephone set or hand-held tone dialer may be used to send commands to the switching unit. • The switching unit is capable of controlling mains, powered loads with the aid of commands received via a telephone.
2. Working of this home automation project.
• Our project uses M-8870 DTMF decoder IC which decodes tone generated by the keypad of cell phone. • When you press any key on your mobile phone while call is in progress, the other person will hear some tones corresponding to the keys pressed. These tones are based on the DTMF (Dual Tone Multi Frequency) technology.
• Data is transmitted as pairs of tones. The receiver detects the valid frequency pair and gives the appropriate BCD code as the output of the DTMF decoder IC. • See the figure below. Cut the microphone wire and you will be able to see 4 wires. Among these wires you need only 2 wires- Ground and Right as shown in figure.
• Select the right wire and connect it as the DTMF input to the decoder circuit. Ground should be connected to common ground of our circuit. • The signals from the microphone wire are processed by the DTMF decoder IC which generates the equivalent binary sequence as a parallel output of Q1, Q2, Q3, and Q4.
Table showing DTMF Low and High frequency tones and decoded output
Button 1 2 3 4 5 6 7 8 9 Low DTMF frequency (Hz) 697 697 697 770 770 770 852 852 852 High DTMF frequency (Hz) 1209 1336 1477 1209 1336 1477 1209 1336 1477 Binary coded output Q1 0 0 0 0 0 0 0 1 1 Q2 0 0 0 1 1 1 1 0 0 Q3 0 1 1 0 0 1 1 0 0 Q4 1 0 1 0 1 0 1 0 1
0 * #
941 941 941
1336 1209 1477
1 1 1
0 0 1
1 1 0
0 1 0
• The output Q4 from the DTMF decoder IC is fed to the clock input of IC 7474 D flip flop which acts as a buffer to the output from M8870 DTMF decoder IC. • IC7474 is configured as Toggling mode that is if it gets a clock pulse the output of this IC (Pin 5) sets to high and further clock pulse resets back the IC. (The outputs toggle whenever a key is pressed). • When we press and release any of the keys among 1, 3, 5, 7, 9 and *, the DTMF decoder IC generates a high pulse which acts as a clock to our flip flop and sets the output flip flop to high. • The output of flip flop is connected to the relay driver circuit via 100Ω resistor; this output energizes the relay coil through BC547 transistor and turns ON the bulb that is connected at the normally open terminal of relay circuit.
3. Components required for home automation:
• • • • •
• • • • • • • •
2 MT 8870 DTMF IC (1) 5 2 LINE LCD DISPLAY (1) 7 DIODE (1) 8 PUSH BUTTON (1) 9 LEDS (4) Regulated power supply DTMF decoder IC (M-8870) Resistors (100Ω; 100kΩ; 70kΩ; 390kΩ) Capacitors (0.1µFx 2) Crystal oscillator (3.579545MHz) IC 7474 D flip flop BC547 Transistor 6V relay
4. Block Diagram and circuit configuration of the Project.
• This circuit makes use of DTMF (Dual Tone Multi Frequency) technique.
Block Diagram
Circuit configuration of the Project:
5. Applications of the Project.
• Wide range of applications in various fields • Telephone answering machine • Industrial applications • Office applications • Institutional applications • Telephone answering machine • Interactive voice response system(IVRS)
6. Merits & Demerits of the Project. Merits
• • • • • • • •
No distance limitation. Instant switching without any delay. Use less components and power consumption is low. Its cost is very less. It cannot be misused unless any other person knows the code.
Demerits
The unit cannot be accessed when the phone is dead. It is only used on phones having DTMF dialing facilities. The wiring becomes complex and costly.
7. Future of This Project.
• • • • Data logging facility can be included. Computer can be interfaced. System reliability can be improved. Wide spread of automation.
