We offer two DTMF shields for Arduino. The basic and the plus models as shown below. Chose the one that fits best your project.

MICO Product Comparison
DTMF Shield MICO DTMF Shield
Basic Model Plus Model
Arduino DTMF Shield
MICO Shield board arduino
Receive DTMF yes-icon yes-icon
 Send DTMF yes-icontwo-tone method yes-iconplayback method
Easy Cell Interface no-icon3-pole yes-icon4-pole Combo port
Detect Cell Ringing no-icon yes-icon
Answer Call button no-icon yes-icon
Play WAV into Calls no-icon yes-icon
Easy Debug no-icon yes-icon
 docs User ManualForum    the basicsgetting startedhelp



Feature explanation:

Detect Cell Ringing: the incoming audio from a cell phone is amplified and fed into an Arduino analog port. The Arduino code will monitor the amplitude of this signal and consider the phone is ringing when signal is above configured threshold.

Answer Call Button: emulates the button on a headset.

Play WAV into calls: play files from the MicroSD card. Required conversion to RAW.

Easy Debug:  the basic DTMF shield require an oscilloscope to measure signal amplitude into the board. The plus model MICO DTMF shield has a built-in amplifier that let you measure the amplitude of the input signal in a provided sample sketch.