1. INTRODUCTION:-
The DTMF based remote monitoring system consists of sensors for sensing the present parameters of the process or machine. The whole system can be installed at a distance place from where these data can be directly sent to the logging system. The data obtained is sent to doctor’s system by converting it into DTMF signals. The DTMF stands for dual tone multiple frequencies. The idea behind this project is generation of DTMF signal for sending data.
In communication any digit may be transmitted in pulse mode or in DTMF mode. We are generating DTMF tones at transmitter end and decoding these tones at receiving end which can be used for transmitting the data from one end to another end.
These signals are decoded at the receiving end and original data is recovered form it by the doctors.

2. Dual-tone multi-frequency (DTMF) signaling is used for telephone signaling over the line in the voice-frequency bandto the call switching center. The version of DTMF used fortelephone tone dialing is known by the trademarked term Touch-Tone (canceled March 13, 1984), and is standardized by ITU-T Recommendation Q.23. Other multi-frequency systems are used for signaling internal to the telephone network As a method of in-band signaling, DTMF tones were also used by cable television broadcasters to indicate the start and stop times of local commercial insertion points during station breaks for the benefit of cable companies. Until better out-of-band signaling equipment was developed in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during the commercial breaks of cable channels in the United States and elsewhere

3. BASIC BLOCK:- DTMF Decoder Power supply LCD display
Microcontroller
LCD display
Device Control system
Different devices

4. CIRCUIT DIAGRAM:-

5. COMPONET USED:- Microcontroller (AT89C51) DTMF decoder 8870
Over load relay 
LCD display 
transformer
capacitors 
resister 
connecting wire

6. Microcontroller :

7. Features of AT89C51 Introduction to AT89C51
The AT89C51 is a CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The on-chip
Flash allows the program memory to be reprogrammed in-system or by a ordinary nonvolatile memory programmer. Atmel AT89C51 is a powerful microcomputer/microcontroller (as they are used inter-changeably) which provides a highly-flexible and cost-effective solution to embedded control applications.many
Features of AT89C51
• Compatible with MCS-51™ Products
• 4K Bytes of In-System Reprogrammable Flash Memory
– Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-Level Program Memory Lock
• 128 x 8-Bit Internal RAM
• 32 Programmable I/O Lines 7

8. DTMF decoder 8870

9. Features
• Low Power Consumption
• Adjustable Acquisition and Release Times
• Central Office Quality and Performance
• Power-down and Inhibit Modes (-02 only)
• Inexpensive 3.58 MHz Time Base
• Single 5 Volt Power Supply
• Dial Tone Suppression
Applications
• Telephone switch equipment
• Remote data entry
• Paging systems
• Personal computers

10. Over load relay  10

11. A Relay Is An Electrically Operated Switch
Many Relays Use An Electromagnet To Operate A Switching Mechanically.
Relay Are Used where Necessary To Control A Circuit By A Low Power Signal.
Many Types Of Relay:
1) SPST
2) SPDT
3) DPST
4) DPDT
5) Contactor Relay
6) Solid State Relay
7) Buchholz Relay
8) Over Load Protection Relay 11

12. LCD display  12

13. transformer  13 13

14. A Transformer Basic Principal is Two 1). Electromagntisim
A Transformer is device there electrical energy form one circuit to another
A Transformer Basic Principal is Two
1). Electromagntisim
2). Electomagnetic induction
A Transformer many Type of losses
1).Hysteresis losses
2).Eddy Currents
3).MagnetoStriction
4).Mechanical losses
5).Stray losses
Replacing the existing GSM air interface is the final and most important step in the evolution of GSM to UMTS i.e. 3G. Recall that one of the criteria for a system to be IMT2000 compliant is that it implements an air interface standard defined by the ITU. In the case of UMTS, the communication over the air interface, or UMTS Terrestrial Radio Access (UTRA) as it is technically known, is achieved using W-CDMA and TD-CDMA. The access parts of the network, called the UMTS Terrestrial Radio Access Network (UTRAN), are based on ATM and it is here that the major changes in upgrading will occur, which of course will also be reflected on the handsets (figure 4). 14 14

15. capacitors  15

16. A Capecitor Is A Passive Two Terminal Electrical Component.
A Capecitor Used to
1)Energy Storage an Electric Field.
2)power Factor Correction.
The Forms Of Practical Capacitors vary Widely.

17. resister 

18. A Resistor Limit Current In a typical Application.
The Resistive Coating Is Spiralled Away In An Automatic Machine Until The Resistance Between The Two Ends Of The Road Is As Possible To The Correct Value.
A Thin Film Carbon Is Deposited On To a Small Ceramic Rod.
Metal leads And End Caps Are Added.
The Resistor Is Covered With An Insulating Coating And Finally Painted With Coloured Bands To Indicate The Resistor Value.

19. WORKING PRINCIPLE
Here microcontroller is the heart of this project ,Firstly the power supply of 5v DC is very essential for this set up, this power supply trigger the microcontroller 8051,then 8051 is directly connected with LCD & device control, LCD gives the info regarding devices that can be operated by microcontroller 8051 & device control here acting as a switch with the help of relays .
DTMF encoder sends the information in the form of frequency from the 2G
hand set ,Then DTMF decoder decode the information in the form of frequency and this information fed to microcontroller pins.Finally microcontroller performs the relative operations.

20. ADVANTAGES
Here we are using 2G technology,2G provides video calling, video streaming ,video conferencing and other tremendous advantages.
with the help of video streaming we can see the project setup as well & operates the same.
Security is another important parameter that is fully protected by microcontroller.