III Gallery

Outcome

Problem: Our washer & dryer are in the basement, so we can't hear when it's done. We're on the second floor and my roommates often walk downstairs multiple times to check when their laundry is done.

Goal: Build a device that sends them a notification when their laundry is done.

Move up Delete Move down

Process: I decided to use a mic that would sense when the washer/dryer buzzer went off. An accelerometer also seemed like a valid choice, but I was more experienced with the mic. I used our Sunday tutorial code as a leaping odd point.

Below is my initial code and circuit.

Move up Delete Move down

// the pin we're reading from
int mic_pin = xxx;
// store the noise level / reading from the electret
// TODO: CREATE A INTEGER VARIABLE NAMED noise_level 
int xxxxxxx 
const int sampleWindow = 50;
// TODO: CREATE A INTEGER VARIABLE NAMED numPins and initialize it to 5 
int 
int ledPins[ 5 ] = { D0, D1, D2, D3, D4 };
void setup(){
  // start serial connection
  Serial.begin(9600);
  for( int i = 0 ; i < numPins; i++ ){
      
    // TODO: Set the pinmode to output
    pinMode(ledPins[ i ], XXXXX);
  }
}
void loop()
{
 
  noise_level = sampleNoise( );
  
  // TODO: Write the noise_level to serial
  // Hint: Serial.println
  displayNoiseOnLEDs();
  // TODO: Wait for 50 milliseconds before looping again
  XXXXXXX
}
void displayNoiseOnLEDs(){
  int level = 200;
  for( int i = 0 ; i < numPins; i++ ){
    int led = ledPins[ i ];
    int desiredLevel = 200 * (i+1);
    if( noise_level > desiredLevel ){
        // TODO: Write the led to HIGH
        
    }else{
        // TODO: Write the led to LOW
    }
  }
}
int sampleNoise( )
{
  unsigned long startMillis = millis(); // Start of sample window
  int highest_sample = 0;
  int lowest_sample = 1000;
  // collect data for 50 mS
  while (millis() - startMillis < sampleWindow)
  {
    int sample = analogRead( mic_pin );
    // invert the range, and convert it to a percent
    sample = map( sample, 0, 4095, 1000, 0 );
    // now see if the sample is the lowest;
    if ( sample > highest_sample ){
    highest_sample = sample ;
    }
    if ( sample < lowest_sample ){
    lowest_sample = sample;
    }
  }
  int peakToPeak = highest_sample - lowest_sample;
  return peakToPeak;
}

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

I remixed the code to send a push notification after the sound passed a certain threshold. I switched from SMS because I didn't want to overload my SMS while debugging. It started a little too sensitive.

I also added a switch and status light so that I could control when it was publishing events. I added a "notifyLed" that would light up whenever an event published. This was primarily for debugging.

Move up Delete Move down


// the pin we're reading from
int mic_pin = A0;
// store the noise level / reading from the electret
int noise_level = 0;
const int sampleWindow = 50;
int notifyLed = D5;
int switchPin = D1;
int statusLed = D0;

void setup(){
  // start serial connection
  pinMode(notifyLed, OUTPUT);
  pinMode(switchPin, INPUT_PULLUP);
  pinMode(statusLed, OUTPUT);


  Serial.begin(9600);
  // Share the value as a noise level
  // reading through the cloud
  Particle.variable( "noise", &noise_level, INT );

}
void loop()
{
  noise_level = sampleNoise( );
  int buttonState = digitalRead( switchPin );
  Serial.println( noise_level );
  delay( 100 );

  if (buttonState == LOW){
    digitalWrite(statusLed, LOW);
  }
  else {
    digitalWrite(statusLed, HIGH);
    if (noise_level > 5500 ){
       Particle.publish("wash_status", "done");
       digitalWrite(notifyLed, HIGH);
    }
    else {
      digitalWrite(notifyLed, LOW);
        }
  }


}




int sampleNoise( )
{
  unsigned long startMillis = millis(); // Start of sample window
  int highest_sample = 0;
  int lowest_sample = 2000;
  // collect data for 50 mS
  while (millis() - startMillis < sampleWindow)
  {
    int sample = analogRead( mic_pin );
    // invert the range, and convert it to a percent
    sample = map( sample, 0, 4095, 6000, 0 );
    // now see if the sample is the lowest;
    if ( sample > highest_sample ){
    highest_sample = sample ;
    }
    if ( sample < lowest_sample ){
    lowest_sample = sample;
    }
  }
  int peakToPeak = highest_sample - lowest_sample;
  return peakToPeak;
}

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Unfortunately, prior to documentation, my mic stopped giving a reading. I tried re-soldering but couldn't get it online. In the name of improvisation, I switched my device to a motion detector that would notify me when it detected motion. This would be great for my dog, who constantly breaks into the kitchen. I used our tutorial code: http://diotlabs.daraghbyrne.me/7-communicating-events/pir/

I used the same switch and status functionality I had in the previous device.

Move up Delete Move down

int statusLed = D0;              // choose the input pin (for PIR sensor)
int notifyLed = D5;                // LED Pin
int pirState = LOW;
int switchPin = D1;
int inputPin = D6;           // we start, assuming no motion detected
int val = 0;                 // variable for reading the pin status

int calibrateTime = 10000;      // wait for the thingy to calibrate

void setup()
{
  pinMode(switchPin, INPUT_PULLUP);
  pinMode(statusLed, OUTPUT);
  pinMode(inputPin, INPUT);
  pinMode( notifyLed, OUTPUT );     // declare sensor as input
}

void loop()
{
  int buttonState = digitalRead( switchPin );
  // if the sensor is calibrated
  if (buttonState == HIGH)
  // starts the function and turns on the light to detect motion
  {
    digitalWrite(statusLed, HIGH);
    if ( calibrated() )
  {
  // get the data from the sensor
    readTheSensor();

    // report it out, if the state has changed
    reportTheData();
  }
}
  else {
  digitalWrite(statusLed, LOW);
}

}
void readTheSensor() {
  val = digitalRead(inputPin);
}

bool calibrated() {
  return millis() - calibrateTime > 0;
}

void reportTheData() {

  // if the sensor reads high
  // or there is now motion
  if (val == HIGH) {

    // the current state is no motion
    // i.e. it's just changed
    // announce this change by publishing an eent
    if (pirState == LOW) {
      // we have just turned on
      Particle.publish("motion_detect", "done");
      // Update the current state
      pirState = HIGH;
      setLED( pirState );
    }
  } else {
    if (pirState == HIGH) {
      // we have just turned of
      // Update the current state
      pirState = LOW;
      setLED( pirState );
    }
  }
}
void setLED( int state )
{
  digitalWrite( notifyLed, state );
}

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Outcome: The initial laundry device worked, but I needed to do additional work to calibrate its sensitivity. I started to wonder if there was a better approach for achieving my goal.

The motion sensor appears to work as planned.

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Bill of parts:

1 Pir sensor (or Adafruit MAX4466 mic)
2 1k ohm resistors
2 LEDs
Jumper wires
Breadboard
Particle microcontroller
1 switch

Move up Delete Move down

Reflection

I was a little bit worried about this project because of my limited experience programming and nonexistent experience with circuits. I was happy to find the basics were fairly accessible, particularly when using IFTTT. While I was disappointed my mic stopped working, I was happy I could hack together a new device. Now that I know I can do this, I look forward to working on more projects!

You can upload files of up to 20MB using this form.

Add Rich Text Add Code Block Add Embeddable Content

Outcome

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution

Attribution