DTMF Application
Application for DTMF encoding/decoding.
Needs Audio Record permission for Decoder to work correctly.
Keypad configuration
Configured keypad frequencies either in DTMF Encoder screen or DTMF CONFIGURATION are valid for decoding and frequencies configured here are used for Decoding. Configuration is shared in all operation with DTMF – encoding,decoding.
DEFAULT Button
Sets keypad frequencies and duration to default values (STANDART).
Encoder
USAGE:
Click on key in keypad to generate tone to produce sound via AudioTrack.
Whole input could be played by clicking Play button – Top right corner.
Encoding uses frequency configurable keypad and phase(duty signal) duration. Encoding creates signal for each key in keypad, each period is long for 2 phase duration, 1.st 1/2 part is generated DTMF signal of symbol, 2nd part is empty(not generating wave).
Play at top left corner of keypad enabled causes immediate signal sound output, could be disabled/enabled by clicking.
Decoder
Uses microphone to get input, while RECORDING enabled service is in realtime decoding sounds to DTMF symbols using current configuration.
You can save Text as text file(.txt) and currently recorded audio as WAV(.wav) file into external memory, if enabled write permission, if this application has permission. Planned feature: AAC encoding
DTMF Android Application 