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Problem with KT3170 DTMF Decoder


New Member
I am attempting to make a circuit with the KT3170 chip. Outputs from chip sent to Arduino pin. Arduino will receive 4 numbers and display them on the LCD screen. It's working
But sometimes the Arduino will take the value from a number 2 times.
Like I dial 1 . Arduino will receive a 11 .
I dial 003 . Arduino will receive a 0003.
I don't know what is wrong.
My code or my circuit?



Active Member
place caps across switches... try something like 10nF
or check oscillations at clock line. Place filter caps (1n-1uF) at VCC line near KT/ arduino chips.

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