Problem with KT3170 DTMF Decoder

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?

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.

MacIntoshCZ said:

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.

Click to expand...

TY I will try.^^

Sectemple said:

TY I will try.^^

Click to expand...

also add 10k res to pins 2-6 (pin->Ground) near to arduino.