Cellphone Based Speed Control of the Motor Now a day's communication is a very important one, mainly cellular communication is an emerging technology. By using cellular phone, we can do many wonders like sending messages, e-mails even we can browse a website using a wap technology. All the above parameters exist in the cellular service. We are going to control electrical appliances like industrial motors with the help of a cellular phone and a dot line.
Microcontroller is a very essential one and almost available in every industry. So we decided to control the electrical appliances by using embedded c, there are two ways to control the appliances with microcontroller. The software can be developed with the help of embedded C language.
When you call your mobile from your cellular phone, the mobile will be connected to a dtmf decoder with headset.Then the cellular phone user has to press the number in his cell phone number pad.
Then the number will be converted in to DTMF (Dual Tone Multi Frequency) signal, which is consists of a low frequency and high frequency waveform. Then that will be transmitted to the landline side.
At the receiver end the DTMF signal will be detected and decoded with the help of a DTMF decoder IC (8870). The DTMF decoder will convert the DTMF waveform in to BCD format. The BCD output format will be given to the microcontroller through the interface circuit.
Then the received BCD data will be converted in to decimal format with the help of software. Then according to the pressed number the Dac will get actuated. Then the DAC output will be connected to control circuit and to the motor