DTMF COM
Description: The Simple MT 8870 Decoder can be operated using any type of DTMF tones emitted from devices such as landlines, mobile phones, computers, and radio transmitters, including ham radios equipped with DTMF capabilities. This decoder can activate a relay when connected to any device that transmits DTMF tones. Additionally, it can be integrated with a computer using a two-way adapter, allowing users to control the DTMF decoder's relay from the computer. When away from the computer, users can call the DTMF decoder from their mobile phone to turn the relay on or off. The design allows for various applications and can be adapted for personal projects. The motivation for creating this DTMF remote control stems from the prevalence of DTMF decoders on platforms like YouTube that primarily activate LEDs rather than controlling loads. This design utilizes a single MT8870 DTMF chip to switch high-power devices, enabling operation from anywhere in the world. The project incorporates a voltage regulator to safely connect a 12-volt supply to the circuit, which is divided into three stages: the regulator, the DTMF decoder, and the load switching mechanism. The regulator steps down 12 volts to a safe 5 volts for the MT8870 chip. A diode is included for reverse polarity protection, and two 100µF capacitors are used. When powered on, a red LED indicates the device is operational. Most components are readily available from electronic stores, with the MT8870 obtainable from eBay, and a 3.579545 MHz quartz oscillator crystal is required. The design is straightforward, focusing on a single-channel DTMF remote control, allowing users to experiment with their own devices. After assembling the device, users should verify all connections. Pressing the '*' button on a mobile phone or computer activates the relay, while pressing the '#' button deactivates it. The simplicity of the design allows for additional numbers to control the device, but adhering to the '*' for activation and '#' for deactivation provides a reliable global remote control system. A resistor and LED connected to pin 15 serve as a valid point indicator, flashing when the DTMF decoder receives a valid tone, aiding in troubleshooting. By connecting a 2.2 kΩ resistor to pin 15, the relay can be activated momentarily, while connecting it to pin 11 allows for latching the relay. The project also supports testing through a computer program by connecting the computer's sound card to the DTMF decoder input. When powered, the red LED should illuminate. For mobile phone connectivity, automatic answer must be enabled; the design was tested with a Nokia 1208 mobile phone.
The Simple MT 8870 DTMF Decoder is a versatile circuit that enables remote control capabilities through DTMF tone recognition. The circuit architecture consists of three primary components: a voltage regulator, the MT8870 DTMF decoder, and a relay driver circuit. The voltage regulator ensures that the circuit operates safely at 5 volts, which is essential for the MT8870 chip. The inclusion of a diode at the input stage protects against reverse polarity, enhancing the reliability of the circuit.
The DTMF decoder interprets the incoming tones and activates the relay based on the recognized signals. By utilizing a two-way adapter, users can connect their mobile phones or computers, allowing for remote operation. The relay can be used to control high-power devices, making this design suitable for various applications, including home automation and remote equipment management.
The circuit's design is user-friendly, with clear instructions for assembly and testing. The use of standard components ensures that hobbyists and engineers can easily replicate the project. The addition of a valid point indicator via an LED connected to pin 15 provides real-time feedback on the decoder's status, which is crucial for troubleshooting and ensuring proper operation.
This DTMF remote control system exemplifies the integration of telecommunications and electronics, offering a practical solution for remote device management. The potential for customization and expansion makes it an excellent platform for further experimentation and development in the field of remote control systems.Running the Simple MT 8870 Decoder from your Cell Phone the devise can be operated from any type of DTMF tones like Land Lines, Mobiles, Computers, Radio Transmitters that send DTMF tones over the air waves, Ham Radio sets with DTMF built in to them it has a lot of uses. 2). The devise can be connected to any thing that sends DTMF tones and it will activate the relay you can even connect your computer to the devise and adding a two way adapter plug your cell phone in to the two way adapter so when you are at the computer your can turn it on the DTMF decoder`s relay. 3). Now when you go out you can phone the DTMF Decoder and turn on the relay or off for that matter from your cell phone you could even add more to my design and build it in to your own projects it is endless the Possibilities you can do.
5). Why I designed the following DTMF remote controls is down to the amount of DTMF decoders on You Tube that don`t have any form of switching a load, Most of them use a single MT8870 DTMF chip but just turn on LEDs this simple design will turn on a relay to power high power devises if you are using a Cell phone then it can be operated from any where in the world. 6). I have designed this project with a voltage Regulator so you can connect 12 volts to the circuit with out harm the design is in 3 stages the Regulator also DTMF Decoder and the switching of the load.
8). The regulator is there so it allows you to run your devise from 12 volts the regulator will drop the 12 volts to 5 volts witch is a safe level for your MT8870 Chip. 9). I have added a simple Diode at the front of the regulator for added protection from reveres polarity the 2 caps are 100uF 25 volts when the devise is switched on the RED LED will light.
10). Now most of the parts you can get from any electronic shop or Store you can get the MT8870 from e-bay here. The Crystal is a 3. 579545MHz Quartz Oscillator Crystal click here. The Transistor is a BC 639 order it from here. 11). My designs below are simple to follow I have only designed it as a single channel DTMF remote control you can experiment with your own devise as it is a basic design it is very simple to switch on or off from any where in the world.
12). When you have finished your own devise check every thing is connected up right now with a Cell phone or Computer press * the relay should switch on and activate your load to turn it off press # keep with them two buttons. 14). Now as the devise is very basic in design more numbers will turn it on or off but if you stick to using * to turn it on then # to turn it off again it makes a very simple global remote control and you will all ways know if it is on or off.
15). Now I have added a resister and LED to Pin 15 this is helpful when the DTMF decoder receives a valid tone it flashed the led indicating it is receiving the tones ok it also helps in fault finding it lets you know the Decoder is working fine it is called the Valid Point or VP for short. Now if you connect the 2. 2k Ohms Resister to pin 15 this will switch the relay on for a few seconds only, Now if you want the relay to latch then connect the 2.
2k resister to pin 11 or what ever pin goes high when you press your buttons. 16). Now to start with I will cover using the DTMF with a Computer program this is all so helpful if you ever need to test the devise to know if it is working fine. 17). Now with your finished devise connect a cable to your computers sound card and the end of the cable to the DTMF decoder input.
When you have done that power up your devise the red LED should switch on now go to your Desk top look for this Icon below. 18). Now if you connect a Cell phone to the DTMF Decoder all you need to do is make sure Automatic Answer is turned on the Phone the phone I used when I designed this project was a Nokia 1208 Mobile phone.
19). Now all you have to do is ring the Mobile phone your DTMF d
The Simple MT 8870 DTMF Decoder is a versatile circuit that enables remote control capabilities through DTMF tone recognition. The circuit architecture consists of three primary components: a voltage regulator, the MT8870 DTMF decoder, and a relay driver circuit. The voltage regulator ensures that the circuit operates safely at 5 volts, which is essential for the MT8870 chip. The inclusion of a diode at the input stage protects against reverse polarity, enhancing the reliability of the circuit.
The DTMF decoder interprets the incoming tones and activates the relay based on the recognized signals. By utilizing a two-way adapter, users can connect their mobile phones or computers, allowing for remote operation. The relay can be used to control high-power devices, making this design suitable for various applications, including home automation and remote equipment management.
The circuit's design is user-friendly, with clear instructions for assembly and testing. The use of standard components ensures that hobbyists and engineers can easily replicate the project. The addition of a valid point indicator via an LED connected to pin 15 provides real-time feedback on the decoder's status, which is crucial for troubleshooting and ensuring proper operation.
This DTMF remote control system exemplifies the integration of telecommunications and electronics, offering a practical solution for remote device management. The potential for customization and expansion makes it an excellent platform for further experimentation and development in the field of remote control systems.Running the Simple MT 8870 Decoder from your Cell Phone the devise can be operated from any type of DTMF tones like Land Lines, Mobiles, Computers, Radio Transmitters that send DTMF tones over the air waves, Ham Radio sets with DTMF built in to them it has a lot of uses. 2). The devise can be connected to any thing that sends DTMF tones and it will activate the relay you can even connect your computer to the devise and adding a two way adapter plug your cell phone in to the two way adapter so when you are at the computer your can turn it on the DTMF decoder`s relay. 3). Now when you go out you can phone the DTMF Decoder and turn on the relay or off for that matter from your cell phone you could even add more to my design and build it in to your own projects it is endless the Possibilities you can do.
5). Why I designed the following DTMF remote controls is down to the amount of DTMF decoders on You Tube that don`t have any form of switching a load, Most of them use a single MT8870 DTMF chip but just turn on LEDs this simple design will turn on a relay to power high power devises if you are using a Cell phone then it can be operated from any where in the world. 6). I have designed this project with a voltage Regulator so you can connect 12 volts to the circuit with out harm the design is in 3 stages the Regulator also DTMF Decoder and the switching of the load.
8). The regulator is there so it allows you to run your devise from 12 volts the regulator will drop the 12 volts to 5 volts witch is a safe level for your MT8870 Chip. 9). I have added a simple Diode at the front of the regulator for added protection from reveres polarity the 2 caps are 100uF 25 volts when the devise is switched on the RED LED will light.
10). Now most of the parts you can get from any electronic shop or Store you can get the MT8870 from e-bay here. The Crystal is a 3. 579545MHz Quartz Oscillator Crystal click here. The Transistor is a BC 639 order it from here. 11). My designs below are simple to follow I have only designed it as a single channel DTMF remote control you can experiment with your own devise as it is a basic design it is very simple to switch on or off from any where in the world.
12). When you have finished your own devise check every thing is connected up right now with a Cell phone or Computer press * the relay should switch on and activate your load to turn it off press # keep with them two buttons. 14). Now as the devise is very basic in design more numbers will turn it on or off but if you stick to using * to turn it on then # to turn it off again it makes a very simple global remote control and you will all ways know if it is on or off.
15). Now I have added a resister and LED to Pin 15 this is helpful when the DTMF decoder receives a valid tone it flashed the led indicating it is receiving the tones ok it also helps in fault finding it lets you know the Decoder is working fine it is called the Valid Point or VP for short. Now if you connect the 2. 2k Ohms Resister to pin 15 this will switch the relay on for a few seconds only, Now if you want the relay to latch then connect the 2.
2k resister to pin 11 or what ever pin goes high when you press your buttons. 16). Now to start with I will cover using the DTMF with a Computer program this is all so helpful if you ever need to test the devise to know if it is working fine. 17). Now with your finished devise connect a cable to your computers sound card and the end of the cable to the DTMF decoder input.
When you have done that power up your devise the red LED should switch on now go to your Desk top look for this Icon below. 18). Now if you connect a Cell phone to the DTMF Decoder all you need to do is make sure Automatic Answer is turned on the Phone the phone I used when I designed this project was a Nokia 1208 Mobile phone.
19). Now all you have to do is ring the Mobile phone your DTMF d
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