DTMF Decoder using MT 8870

Discussion in 'The Projects Forum' started by jithinnandan, Mar 12, 2013.

  1. jithinnandan

    Thread Starter New Member

    Mar 12, 2013
    Dear all,
    I'm working on a circuit to control the water pump based on DTMF code and cellphone.
    But the DTMF section is not working properly.
    While sending the DTMF code, pin # 11 to 14 is on high and no change in state and pin # 16 is at low state.
    This is the case for all DTMF codes which we are sending.
    Kindly see the circuit and somebody please help me. :(
  2. absf

    Senior Member

    Dec 29, 2010