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Dial Tone Multi Frequency (DTMF) driver by Pepi

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DTMF driver by Pepi


Lets imagine some situation. We are AT the Holiday. Sailing in transatlantic ship. Suddenly we realized that we have left iron plugged to power grid. No one is home, so only one solution is to call to your neighbors. Ok, but what if neighbors aren’t at home? Coming back? Calling for firemen’s? No way!, you can just call for telephone number that is connected with driver, wait until it start, press zero at keyboard and no more problem. This device has this function.
principle of work based on receiving and decoding Dial Tone Multi Frequency (DTMF) by integrated circuit – MT8870. Than signal in binary mode goes to microcontroller input – Atmega8-16PU. microcontroller read logic state at inputs and depend of tones from phone, change input mode.
From microcontroller inputs signal goes to optiotracs MOC3021. Optiotracs control triacs BT137/600. this allow to control six devices at the same time. Why triacs? because relays may scintillate with big load. We don’t want to make a fire. Besides relays coil takes much more current then tiacs gate.
At shops you can find a lot of remote controllers, but they works thanks to radio transmission, or IR. Range of those is sharp limited. At this project, range is global. Everything you need is a mobile in range. Another positive sites are: functionality, simple work, small dimensions, safe work in easy – fire places, reliability.
More information you can find at https://www.elektroda.pl/rtvforum/topic1605226.html

 

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