What is DTMF control?
Dual tone multi-frequency (DTMF) is the sounds or tones generated by a telephone when the numbers are pressed. These tones are transmitted with the voice channel. DTMF is used to control automated equipment and signal user intent, such as the number they wish to dial. Each key has two tones at specific frequencies.
What is DTMF based home automation?
DTMF Home Automation lets you operate your home appliances like lights and water pump from your office or any other remote place. So if you forgot to switch off the lights or other appliances while going out, it helps you to turn off the appliance with your cell phone.
When was the DTMF system first used?
November 18, 1963
DTMF was known throughout the Bell System by the trademark Touch-Tone. The term was first used by AT in commerce on July 5, 1960, and was introduced to the public on November 18, 1963, when the first push-button telephone was made available to the public.
What frequency are DTMF tones?
The DTMF keypad for consumer use is designed in a four-row by three-column matrix. Each dial row is represented by a low tone frequency and each column by a high tone frequency. The frequencies used are 697 Hz, 770 Hz, 852 Hz, 941 Hz, 1209 Hz, 1336 Hz, 1477Hz, and 1633 Hz.
What is smart device automation?
Home automation is the automatic control of electronic devices in your home. These devices are connected to the Internet, which allows them to be controlled remotely. With home automation, devices can trigger one another so you don’t have to control them manually via an app or voice assistant.
What is DTMF circuit?
The operation of Dual Tone Multi-Frequency is when a caller produces a call tone that includes two frequencies. It is conveyed through the communication media or telephone line. The telephone exchange switch room uses a DTMF decoder to decode the frequencies of the caller into digital code.
What is DTMF duration?
The tone duration of DTMF is variable depending on the system used. Standard Whelen timing is 40ms tone, 20ms space, where standard Motorola rate is 250ms tone, 250ms space. Federal Signal ranges from 35ms tone 5ms space to 1000ms tone 1000ms space. Genave Superfast rate is 20ms tone 20ms space.
Why we use microcontroller 8051 in remote control circuit?
Till now we have seen so many circuits to control the devices or appliances from the remote place but the main advantage of this circuit is that it’s simple and we can operate it from anywhere in the world. We are using the microcontroller 8051 in this circuit for controlling different devices.
What is the input pin of 8051 motor driver?
Motor driver’s input pin 2, 7, 10 and 15 are connected at 8051’s pin number P2.6, P2.3, P2.0 and P2.7 respectively. Here we have used two DC motors to drive robot in which one motor is connected at output pin of motor driver 3 and 6 and another motor is connected at 11 and 14.
What is the 8051 instruction set used for?
The 8051 instruction set is optimized for 8-bit control applications. It provides a variety of fast addressing modes for accessing the internal RAM to facilitate byte operations on small data structures.
What is the use of motor driver in microcontroller?
Motor driver is used for driving motors because microcontroller does not supply enough voltage and current to motor. So we add a motor driver circuit to get enough voltage and current for motor. By collecting commands from 8051, motor driver drive motor according to commands.