Circuit to Identify Pressed Switches of a Mobile Phone using Arduino (Part 1 of 2)

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We had already seen the circuit to control four LEDs using mobile phone through MT8870 IC. Here, we will design a circuit to detect the pressed switches of a mobile phone using arduino uno.

Circuit is done as shown in the following diagram. Before doing the circuit, you must read my previous blogs on :

4000-4000-another-copy (4th copy)Connections can be summarized as :

  • Pin 14 of MT8870D is connected to the 10th digital pin of arduino.
  • Pin 13 of MT8870D is connected to the 11th digital pin of arduino.
  • Pin 12 of MT8870D is connected to the 12th digital pin of arduino.
  • Pin 11 of MT8870D is connected to the 13th digital pin of arduino.

Working

Output pins Q4 (14), Q3 (13), Q2 (12) and Q1 (11) of MT8870D is connected to the digital pins of arduino uno. Connect a mobile phone to the audio jack in the circuit and press switches in your mobile phone. If ‘1’ is pressed, output will be 0001. If ‘2’ is pressed, output will be 0010. If ‘3’ is pressed, output will be 0011. If ‘4’ is pressed, output will be 0100. We will upload a program to arduino in such a way that, arduino uno will always listen to the signals reaching the 10th, 11th, 12th and 13th digital pins of arduino uno. If signals reaching on each digital pins of arduino is “1”, arduino will read it as “1” which can be seen in serial monitor. Otherwise arduino will read it as “0”. Program to be uploaded to the arduino board is given in next part.

Continued in Next Part (Part 2) >>>>

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paulpp644

A deep electronic enthusiast who spent most of my time for electronic experiments. I am also interested in publishing my experiments in my blog for helping other electronics enthusiasts.