====== DTMF DECODER "HW-005" (MT8870 chip) ====== ===== FEATURES ===== * Power Input: 5V Nominal (4.5V - 5.5V) * Onboard 3.5mm jack input Facility * MT8870 Based Frequency Decoder * 5 Channel Interface * Detects 0-9, A-D, *, # * LED notifier for Output state * 2.54” Pin pitch * Board Dimension: 37 x 25 x 12 mm (l x w x h) ==== DOCUMENTATION ==== * {{ :documentation:electronique:modules_kits:dtmf_decoder:mt8870-dtmf-audio-decoder-module-datasheet.pdf |MT8870 Datasheet}} * {{ :documentation:electronique:modules_kits:dtmf_decoder:mt8870-schematic-diagram.pdf |Module Schematic Diagram}} ===== BLOCK DIAGRAM ===== {{:documentation:electronique:modules_kits:dtmf_decoder:dtmf-module_block_diagram.jpg?direct&400|}} ===== PINOUT ===== {{:documentation:electronique:modules_kits:dtmf_decoder:dtmf-decoder-pinout.jpg?direct&600|}} \\ {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-dtmf-audiospeech-decoding-telephone-module.jpg?direct&400|}} ^ PIN ^ FUNCTION ^ COMMENT ^ | Q1 | Binary Bit 1 | | | Q2 | Binary Bit 2 | | | Q3 | Binary Bit 3 | | | Q4 | Binary Bit 4 | | | StQ | Delayed String Output | Represents Binary Bit 0 | | StQ | Power Down Input | | | IN | Inhibit Input | Logic high inhibits the detection of tones representing characters A, B, C and D | | VCC | DC Supply Input | 4.5V - 5.5V (5.0V Nominal) | | GND | Ground | | \\ {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-state.jpg?direct&400|}} ===== INTERFACING ===== {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-interfacing-diagram.png?direct&600|}} ===== MT-8870 ===== {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-dtmf-ic-block-diagram.jpg?direct&400|}} \\ {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-dtmf-ic-pinout.png?direct&600|}} ===== CODE SAMPLES ===== ==== ARDUINO LIBS ==== * https://www.arduino.cc/reference//en/libraries/mt8870/ * https://github.com/RobTillaart/MT8870 ==== Sample 1 ==== {{:documentation:electronique:modules_kits:dtmf_decoder:dtmf_interfacing_diagram.png?direct&400|}} \\ {{:documentation:electronique:modules_kits:dtmf_decoder:mt8870-circuit-.jpg?direct&400|}}


void setup() {
  Serial.begin(9600);
  pinMode(3, INPUT);
  pinMode(4, INPUT);
  pinMode(5, INPUT);
  pinMode(6, INPUT);
  pinMode(7, INPUT);
}

void loop() {
  uint8_t number;
  bool signal ;  
  signal = digitalRead(3);
  if(signal == HIGH)	/* If new pin pressed */
   {
    delay(250);
    number = ( 0x00 | (digitalRead(7)<<0) | (digitalRead(6)<<1) | (digitalRead(5)<<2) | (digitalRead(4)<<3) );
      switch (number)
      {
        case 0x01:
        Serial.println("Pin Pressed : 1");
        break;
        case 0x02:
        Serial.println("Pin Pressed : 2");
        break;
        case 0x03:
        Serial.println("Pin Pressed : 3");
        break;
        case 0x04:
        Serial.println("Pin Pressed : 4");
        break;
        case 0x05:
        Serial.println("Pin Pressed : 5");
        break;
        case 0x06:
        Serial.println("Pin Pressed : 6");
        break;
        case 7:
        Serial.println("Pin Pressed : 7");
        break;
        case 0x08:
        Serial.println("Pin Pressed : 8");
        break;
        case 0x09:
        Serial.println("Pin Pressed : 9");
        break;
        case 0x0A:
        Serial.println("Pin Pressed : 0");
        break;
        case 0x0B:
        Serial.println("Pin Pressed : *");
        break;
        case 0x0C:
        Serial.println("Pin Pressed : #");
        break;    
      }
  }
}

===== DTMF (Dual Tone Multi Frequency) ===== ^ Hz ^ 1209 ^ 1336 ^ 1477 ^ 1633 ^ ^ 697 | 1 | 2 | 3 | A | ^ 770 | 4 | 5 | 6 | B | ^ 852 | 7 | 8 | 9 | C | ^ 941 | * | 0 | # | D |