DTMF MT8870 Audio Decoder Module

DTMF (Dual Tone Multi-Frequency) is a telecommunications signaling method that uses a combination of two sinusoidal frequencies to generate a dial tone. 

The MT8870 module is a DTMF receiver that decodes the key pressed on a telephone keypad using a band-split filter. A band-split filter, as the name implies, splits the consolidated frequencies to identify them. The MT8870 module then converts the DTMF signal into 4-bit digital representing all 16 possible combinations on a standard telephone keypad. 

Specifications:

• Operating Voltage: 5V
• Interface type: Digital
• On-board MT8870 frequency decoder chip
  
• On-board audio input interface
  
• On-board LED lights for output state indication
  
• PCB Size: 26.5 x 24.5 mm

Library: None

Inclusions:

• DTMF decoder module x1

• Datasheet
• Schematic
• Sample code