Dual-tone multi-frequency decoder Encoder DTMF audio generator Receive 30 serial data at one time

DTMF signal decoding and encoding module

I. Overview:

 DTMF V1Is a dual-tone multi-frequency decoding encoding module.

Code sending process:Is input through the serial portASCIIAfter being received by the module, the code is converted into a dual-tone multi-frequency code, and then converted into an audio signal.3.5MMEmitted by the audio interface.

Code receiving process: Is used3.5MMThe audio interface converts the received audio signal into a dual-tone multi-frequency code, and then toASCIIThe code is sent through the serial port.

  This module can use audio cable to connect input and output together, and send and receive data at the same time. The module can receive serial port at one time.30Data waiting to be sent.

Application:

● Remote equipment control;

● Dual-tone multi-frequency code decoding;

● Dual-tone multi-frequency code coding;

Third, the technical parameter table:

4. Features: (1) Receive and send data through the serial port.
(2) Input and output can be connected together with audio cable, and data can be sent and received at the same time.
(3) The module can receive 30 data from the serial port at a time and wait for transmission.
(4) The received data is sent out through the serial port immediately.

5. Drive mode: serial port communication format: baud rate 9600, no parity, 8-bit data, 1-bit stop

6. Application: Decoding and encoding of dual-tone signals; remote control equipment.

7. Module interface:
  
(1) Communication interface P2:
5V: Positive power connector (5V).
GND: power ground interface.
RXD: the receiving end of the module; connected to the TXD of the microcontroller (MCU)
TXD: the transmitting end of the module; connected to the MCU (MCU) receiving end RXD

(2) Signal input interface J1: 3.5MM audio input interface.

(3) Signal output interface J2: 3.5MM audio output interface.

Module and wiring block diagram:

 Note: Please do not connect the circuit module directly to the serial port of the computer.RS232turnTTLModule) converts signals intoTTLOnly level signals can be connected to the circuit module, otherwise the module will be damaged. (RS232The signal is negative15Fu Zhizheng15Volt, TTL232The signal is0Fu Zhizheng5Volts)

Encoding and decoding

Keystroke or digital information is converted into a two-tone signal during encoding and sent.DTMFThe presence of keystrokes or digital information is detected in the signal. OneDTMFThe signal is made up of audio signals of two frequencies. The frequencies of these two audio signals are from two pre-assigned frequency groups:Line frequencyGroup or column group. Each pair of such audio signals uniquely represents a number or symbol. Usually on the phone16Keys, with10Number keys0~9with6EachFunction keys*,#,A,B,C,D. According to the combination principle,8Different single audio signals. So the available frequencies are also8This is called multi-frequency, and because it uses arbitrarily extracted from high and low frequencies1Combination for encoding, so it is also called"8Take2"Encoding technology. according toCCITT, The multiple frequencies used internationally are697Hz,770Hz,852Hz,941Hz,1209Hz,1336Hz,1477Hzwith1633HzWait8Species. Use this8Can form16Different combinations to represent16Different numbers orFunction keysSee the table for specific combinations1

Note: Only after the circuit wiring is checked, can the power be turned on. Reversing the power supply will burn out the circuit.

provide:Test software and a PDF manual. (Send by email).