How to check if the MT8880 is transmitting a DTMF signal?

[prasannabalaji]

DTMF tranceiver

hi,

i am using MT8880 which is a DTMF transceiver..after initialisation of control reg i am giving the input of 7 i want to know, how to check that wheather this IC is txansmitting DTMF signal or not

thank u in advance

 

[servicemann]

DTMF tranceiver

Many years ago I used to play with the MT8880.
You can HEAR the signals on the output.

 

[Jepeto]

Re: DTMF tranceiver

You can record the tone using soundcard line input (protect soundcard input with serial 1K resistor and large capacitor) or use the mic if the circuit connected to telephone line
There are many free sound software with spectrum analyze capability
so and you can see the frequencies

Audio Spectrum Analysis
http://www.visualizationsoftware.com/gram.html

http://www.spectrascope.com/
**broken link removed**