DT210 Encoder Decoder DTMF Audio Decoding Digital Display LCD Instruments Module
100% Brand New And High Quality
1, Operating voltage 7 ~ 12 VDC
2, Operating current <50 mA
3, Size 56x45x20 mm length X width X height
4, the module interface:
(1) Interface P1:
VDD: positive power supply connector.
GND: power ground interface.
(2) signal input J1: is 3.5MM audio input interface.
(3) signal output connector J2: is 3.5MM audio output interface
Interface Display and operating instructions:
(1) Key Description:
UP: Self-keyed.
DOWN: from minus key.
ENTER: clear the screen / signals.
FUN: received signal / transmit signal selection.
4.1 receiving DTMF code
Interface display font:
The first line "Receive:"
The second line ""
Key actions:
UP: Not used;
DOWN: Not used;
ENTER: clear screen
FUN: set change (DTMF code to receive / transmit DTMF code)
Note: Received DTMF code is displayed on the second line.
4.2, send DTMF code
Interface display font:
The first line of "Send: 5"
The second line "5645"
Key actions:
UP: self-imposed bond;
DOWN: Decrement key;
ENTER: send out the selected DTMF code
FUN: set change (DTMF code to receive / transmit DTMF code)
Note: Issue of DTMF code is displayed on the second line.
Note: checked after the circuit wiring is correct, and try to power. Power will burn circuit reversed..
Encoding and decoding
In encoding digital information is converted to keystrokes or double audio signal and transmitting, to detect the presence of keystrokes or digital information received DTMF signal decoding. A DTMF signal from the audio signal constituted of two frequencies superimposed. Frequency group frequencies of the two audio signals from the two pre-allocated: line frequency group or column frequency group. Each of such audio signal represents a unique number or symbol. Telephone usually has 16 keys, including 10 numeric keys 0 to 9 and six function keys *, #, A, B, C, D. Because according to a combination of theory, it should normally eight different single audio signal. Therefore, there can be eight kinds of frequency, it is known as multi-frequency, and because it uses are drawn from high-frequency to any one kind of combination to be encoded, it is also known as "take two 8" coding techniques. According to CCITT recommendations, a variety of frequencies used internationally as 697Hz, 770Hz, 8 种 852Hz, 941Hz, 1209Hz, 1336Hz, 1477Hz and 1633Hz and so on. With these eight frequencies can form 16 different combinations, thus representing 16 different numbers or function keys, the specific combination of Table 1
Package included:
1 x DT210 Decoder Encoder DTMF Module
