Arduino adventures: triggering MP3 files with distance sensor

Finally got the circuit built to be able to read the distance sensor and the MP3 board, so now I can trigger a selected MP3 to play when something passes the sensor. What I built previously was overly-complicated and was most likely shorting out.

The videos show the sensor working from 1ocm distance, but this is easy to vary. They also show the sound looping if the object sensed stays in range, and also two separate pieces of audio being triggered. This was changed in the code before being uploaded. The code used is below.

Next to make it play a random one of the MP3 files each time the sensor is triggered!

//code rearranged by Javier Muñoz 10/11/2016 ask me at javimusama@hotmail.com
#include <SoftwareSerial.h>

#define ARDUINO_RX 5//should connect to TX of the Serial MP3 Player module
#define ARDUINO_TX 6//connect to RX of the module

#define trigPin 13//for the distance module
#define echoPin 12


SoftwareSerial mySerial(ARDUINO_RX, ARDUINO_TX);//init the serial protocol, tell to myserial wich pins are TX and RX

////////////////////////////////////////////////////////////////////////////////////
//all the commands needed in the datasheet(http://geekmatic.in.ua/pdf/Catalex_MP3_board.pdf)
static int8_t Send_buf[8] = {0} ;//The MP3 player undestands orders in a 8 int string
                                 //0X7E FF 06 command 00 00 00 EF;(if command =01 next song order) 
#define NEXT_SONG 0X01 
#define PREV_SONG 0X02 

#define CMD_PLAY_W_INDEX 0X03 //DATA IS REQUIRED (number of song)

#define VOLUME_UP_ONE 0X04
#define VOLUME_DOWN_ONE 0X05
#define CMD_SET_VOLUME 0X06//DATA IS REQUIRED (number of volume from 0 up to 30(0x1E))
#define SET_DAC 0X17
#define CMD_PLAY_WITHVOLUME 0X22 //data is needed  0x7E 06 22 00 xx yy EF;(xx volume)(yy number of song)

#define CMD_SEL_DEV 0X09 //SELECT STORAGE DEVICE, DATA IS REQUIRED
                #define DEV_TF 0X02 //HELLO,IM THE DATA REQUIRED
                
#define SLEEP_MODE_START 0X0A
#define SLEEP_MODE_WAKEUP 0X0B

#define CMD_RESET 0X0C//CHIP RESET
#define CMD_PLAY 0X0D //RESUME PLAYBACK
#define CMD_PAUSE 0X0E //PLAYBACK IS PAUSED

#define CMD_PLAY_WITHFOLDER 0X0F//DATA IS NEEDED, 0x7E 06 0F 00 01 02 EF;(play the song with the directory \01\002xxxxxx.mp3

#define STOP_PLAY 0X16

#define PLAY_FOLDER 0X17// data is needed 0x7E 06 17 00 01 XX EF;(play the 01 folder)(value xx we dont care)

#define SET_CYCLEPLAY 0X19//data is needed 00 start; 01 close

#define SET_DAC 0X17//data is needed 00 start DAC OUTPUT;01 DAC no output
////////////////////////////////////////////////////////////////////////////////////


void setup()
{
  Serial.begin(9600);//Start our Serial coms for serial monitor in our pc
mySerial.begin(9600);//Start our Serial coms for THE MP3
delay(500);//Wait chip initialization is complete
   sendCommand(CMD_SEL_DEV, DEV_TF);//select the TF card  
delay(200);//wait for 200ms
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);

}

void loop()
{
  if(measureDistance(trigPin,echoPin)<50){
sendCommand(CMD_PLAY_WITHFOLDER, 0X0203);//play the third song of the second folder
delay(1000);//wait to avoid errors
}
delay(300);
}

void sendCommand(int8_t command, int16_t dat)
{
 delay(20);
 Send_buf[0] = 0x7e; //starting byte
 Send_buf[1] = 0xff; //version
 Send_buf[2] = 0x06; //the number of bytes of the command without starting byte and ending byte
 Send_buf[3] = command; //
 Send_buf[4] = 0x00;//0x00 = no feedback, 0x01 = feedback
 Send_buf[5] = (int8_t)(dat >> 8);//datah
 Send_buf[6] = (int8_t)(dat); //datal
 Send_buf[7] = 0xef; //ending byte
 for(uint8_t i=0; i<8; i++)//
 {
   mySerial.write(Send_buf[i]) ;//send bit to serial mp3
   Serial.print(Send_buf[i],HEX);//send bit to serial monitor in pc
 }
 Serial.println();
}

long measureDistance(int trigger,int echo){
   long duration, distance;
  
  digitalWrite(trigger, LOW);  //PULSE ___|---|___
  delayMicroseconds(2); 
  digitalWrite(trigger, HIGH);
  delayMicroseconds(10); 
  digitalWrite(trigger, LOW);
  
  duration = pulseIn(echo, HIGH);
  distance = (duration/2) / 29.1;
   Serial.println("distance:");
   Serial.println(distance);
  return distance;

}

I Am Sensor – Godzuino

A track created using the audio signals from Arduino, via four over-sized sensors: Twitch, Flexilla, Bütton and Anomomehelmet.

I Am Sensor artwork (Photo: Alexa Pollmann, typography & logo: Kat Hornstein)
I Am Sensor artwork (Photo: Alexa Pollmann, typography & logo: Kat Hornstein)

I Am Sensor – Twitch (tilt switch) code and circuit

The code and circuit for the Arduino-powered giant tilt switch was adapted from this page – http://starter-kit.nettigo.eu/2010/tilt-sensor/

Starting circuit for giant tilt switch
Starting circuit for giant tilt switch
Circuit for giant tilt switch
Circuit for giant tilt switch
/// Defining a pin for the tilt sensor
#define SENSOR_PIN 2
// Defining a pin for the LED diode
#define LED_PIN 13
// Defining a pin for the piezo
#define PIEZO_PIN 3
// Defining sensitivity time [ms]
#define SENSOR_TIME 100
// Defining alarm duration time [ms] (5000 ms = 5 s)
#define ALARM_TIME 10000

// variable storing sensor's switching time
unsigned long sensor_time;
// variable storing alarm duration
unsigned long alarm_time;
// variable storing pitch change time
unsigned long signal_time = 0;
// variable storing the pitch value
// 0 - no sound
// 1 - first tone
// > 1 - second tone
byte sound_tone = 0;

// alarm siren function
void alarm_signal()
{
  if (sound_tone != 0) // checking if the siren should be turned on
  {
    if (millis() - signal_time > 750) // checking tone duration
    {
      signal_time = millis(); // storing the time when the tone was turned on
      sound_tone = ~sound_tone; // turning on the second tone
    }

    if (sound_tone == 1) // first tone
    {
      tone(PIEZO_PIN, 300);
    }
    else // second tone
    {
      tone(PIEZO_PIN, 200, 100);
      delay(1000);
      tone(PIEZO_PIN, 400, 100);
      delay(1000);
    }
  }
  else
  {
    noTone(PIEZO_PIN); // Sound off
  }
}

// Function invoked when the alarm is off
void alarm_on()
{
  alarm_time = millis(); // storing the time when the tone was turned on
  digitalWrite(LED_PIN, HIGH); // LED on
  sound_tone = 1; // Turning alarm siren on
}

// Function invoked when the alarm is off
void alarm_off()
{
  if (millis() - alarm_time > ALARM_TIME) // checking alarm duration
  {
    digitalWrite(LED_PIN, LOW); // LED off
    sound_tone = 0; // Turning alarm siren off
  }
}

// function checking sensor's state
void check_sensor()
{
  // checking sensor's state
  if (digitalRead(SENSOR_PIN) == HIGH)
  {
    // Action if off

    if (sensor_time == 0) // checking if the state was changed
    {
      sensor_time = millis(); // storing sensor's activation time
    }
    // Condition, if sensor's state lasts for a specified time
    else if (millis() - sensor_time > SENSOR_TIME)
    {
      alarm_on();
    }
  }
  else
  {
    // Action if off
    sensor_time = 0;
    alarm_off();
  }
}

void setup()
{
  // Setting the sensor's pin as input
  pinMode(SENSOR_PIN, INPUT);
  // Turning internal Pull Up resistor on
  digitalWrite(SENSOR_PIN, HIGH);
  pinMode(LED_PIN, OUTPUT);
}

void loop()
{
  check_sensor();
  alarm_signal();
}

Second prototype for over-sized Arduino-powered tilt switch

Second prototype for over-sized Arduino-powered tilt switch - clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch – clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch - clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch – clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch - clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch – clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch - clear acrylic tube
Second prototype for over-sized Arduino-powered tilt switch – clear acrylic tube

First prototype for over-sized Arduino-powered tilt switch

Photos of the first prototype over-sized Arduino-powered tilt switch – now christened ‘Twitch‘.

First prototype for over-sized Arduino-powered tilt switch
Over-sized Arduino-powered tilt switch – cardboard tube version.
Over-sized Arduino-powered tilt switch - cardboard tube version.
Over-sized Arduino-powered tilt switch – cardboard tube version.
First prototype for over-sized Arduino-powered tilt switch
First prototype for over-sized Arduino-powered tilt switch
Over-sized Arduino-powered tilt switch - wearable, back view.
Over-sized Arduino-powered tilt switch – wearable, back view.
Over-sized Arduino-powered tilt switch - wearable, front view.
Over-sized Arduino-powered tilt switch – wearable, front view.