We control the TV or the musical center with gestures

/ * Swipe Remote Control

This sketch uses an ultrasonic rangefinder to determine the user's gesture and outputs an IR signal to a sony TV based on the command given.
- High swipe (> 10in) = Channel Up
- Low swipe = Channel Down
- High hold (> 10in) = Volume Up
- Low hold = Volume Down
- Cover sensor (<3in) = Turn On / Off

Created by Dan Nicholson.

This example code is in the public domain.

This code uses the IRremote library (https://github.com/shirriff/Arduino-IRremote)

* /
#include 

// Defines for control functions
#define CONTROL_CH 1 // Channel change
#define CONTROL_VOL 2 // Volume
#define CONTROL_POW 3 // Power

#define CONTROL_UP 1
#define CONTROL_DOWN -1

#define DIST_MAX 20 // Maximum distance in inches, anything above is ignored.
#define DIST_DOWN 10 // Threshold for up / down commands. If higher, command is "up". If lower, "down".
#define DIST_POW 3 // Threshold for power command, lower than = power on / off

// IR PIN
const int irPin = 3; // this is defined in the library, this var is just a reminder. CHANGING THIS WILL NOT CHANGE PIN IN LIBRARY
// 2 Pin Ping Sensor
const int pingPin = 8;
const int echoPin = 7;
// Confirmation LED Pins
const int led = 13; // internal LED for up / down debugging
const int ledR = 11;
const int ledG = 10;
const int ledB = 9;
// LED on timer
unsigned long timer;
// IR transmitter object
IRsend irsend;
// Power confirmation flag (needs two swipes to send signal)
boolean powerConfirmed = false;

void setup () {
  // initialize serial communication and set pins
  Serial.begin (9600);
  pinMode (led, OUTPUT);
  pinMode (ledR, OUTPUT);
  pinMode (ledG, OUTPUT);
  pinMode (ledB, OUTPUT);
  pinMode (pingPin, OUTPUT);
  pinMode (echoPin, INPUT);
  timer = millis ();
}

void loop ()
{
 
// Serial.println (millis ());
  long duration, inches;
  int value;

  // Check for a reading
  duration = doPing ();
 
  // Timer to confirm actions (currently only power)
  if (timer && timer <(millis () - 5000) && (millis ()> 5000))
  {
    Serial.println ("timer reset");
    timer = false;
  }

   digitalWrite (led, LOW);
   setColor (0, 0, 0); // off

 
  // convert the time into a distance
  inches = microsecondsToInches (duration);

  // If less than max inches away, act
  if (inches  DIST_MAX)
      {
        doIR (CONTROL_CH, value); // swipe
      }
      else
      {
        // volume
        int d = 500; // first delay is longer for single volume change
        // repeat until hand is removed
        while (inches  DIST_DOWN)
  {
    digitalWrite (led, HIGH);
    return CONTROL_UP;
  }
  else
  {
    digitalWrite (led, LOW);
    return CONTROL_DOWN;
  }
}

/ *
* Fire off correct IR code
* /
void doIR (int control, int val)
{
  switch (control)
  {
  case CONTROL_POW:
    // power
    Serial.println ("power on / off 0xa90");
    for (int i = 0; i <3; i ++)
    {
      setColor (255, 0, 0);
      irsend.sendSony (0xa90, 12); // Sony TV power code
      delay (40);
    }
    break;
  case CONTROL_CH:
    setColor (0, 255, 0);
    // output 'channel up / down' depending on val
    if (val == CONTROL_UP)
    {
      digitalWrite (led, HIGH);
      for (int i = 0; i <3; i ++)
      {
        irsend.sendSony (0x90, 12);
        delay (40);
      }
      Serial.println ("channel up 0xD00A");
    }
    else // down
    {
      for (int i = 0; i <3; i ++)
      {
        irsend.sendSony (0x890, 12);
        delay (40);
      }
      Serial.println ("channel down 0x3002");
    }
    break;
  case CONTROL_VOL:
    setColor (0, 0, 255);
    // output 'volume up / down' depending on val
    if (val == CONTROL_UP)
    {
      digitalWrite (led, HIGH);
      for (int i = 0; i <3; i ++)
      {
        irsend.sendSony (0x490, 12);
        delay (40);
      }
      Serial.println ("volume up 0x490");
    }
    else // down
    {
      for (int i = 0; i <3; i ++)
      {
        irsend.sendSony (0xC90, 12);
        delay (40);
      }
      Serial.println ("volume down 0xC90");
    }
    break;
  }
}
void setColor (int red, int green, int blue)
{
  analogWrite (ledR, red);
  analogWrite (ledG, green);
  analogWrite (ledB, blue);
}

long doPing ()
{
  digitalWrite (pingPin, LOW);
  delayMicroseconds (2);
  digitalWrite (pingPin, HIGH);
  delayMicroseconds (5);
  digitalWrite (pingPin, LOW);
  return pulseIn (echoPin, HIGH);
}

long microsecondsToInches (long microseconds)
{
  // According to Parallax's datasheet for the PING))), there are
  // 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
  // second). This gives the distance traveled by the ping, outbound
  // and return, so we divide by 2 to get the distance of the obstacle.
  // See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
  return microseconds / 74/2;
}

long microsecondsToCentimeters (long microseconds)
{
  // The speed of sound is 340 m / s or 29 microseconds per centimeter.
  // The ping travels out and back, so to find the distance of the
  // object we take half of the distance traveled.
  return microseconds / 29/2;
}