Outcome

Move up Delete Move down

Problem Statement: Our laundry machine is located in the basement and my roommates often have to check multiple times to see when their laundry is done.

Goal: Create a device that notifies my roommates when their laundry is done.

Process:

I decided to use a microphone that would detect the washer/dryer buzzer. An accelerometer seemed like an equally valid option, but we had done a tutorial with the mic on Sunday so I went in that direction.

The code I started with is below, which I took from our Sunday tutorial. You can also see my circuit's early stages.

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 our Sunday tutorial code to provide a notification when the laundry machine stopped running. To do so, I used an IFTTT applet to send me a push notification whenever the sound crossed a certain threshold. I started with SMS but switched to IFTTT push notifications because I didn't want to go over my SMS limit.

I added a switch and status light so I could know when it was publishing events and turn it off while I debugged.

I also added a "notification" LED that would light whenever the event published. This was mainly helpful when I was debugging and trying to calibrate the sound sensitivity.

Move up Delete Move down

// this was my original code for a laundry notification

// 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, on Thursday night, something happened to my microphone and it stopped receiving information. I tried re-soldering but couldn't get it to work.

In the name of improvisation, I switched to a device that would send me a notification whenever it detected motion. It uses the same switch and status light functionality that my original laundry device implemented. I thought this could notify me when my dog breaks into the kitchen.

The code is repurposed from our lab: http://diotlabs.daraghbyrne.me/7-communicating-events/pir/.

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 event
    if (pirState == LOW) {
      // this publishes an event for an IFTTT applet
      Particle.publish("motion_detector", "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

Outcome: The laundry device effectively sent push notifications based on a predefined sound threshold. It was a little too sensitive, which needs some additional work.

The improvised motion detector appears to work as intended.

The final video, diagram, and parts are below.

( I'm not sure if this video is showing up. It's below the 20mb threshold, but doesn't seem to be working)

Move up Delete Move down

Show Advanced Options

Move up Delete Move down

Motion sketch

Show Advanced Options

Move up Delete Move down

Bill of parts (both projects)

* Two 1k resistors

* 1 PIR sensor (or MAX4466 mic)

* 2 LEDs

* 1 switch

* Jumper wires

* Breadboard

* Particle microcontroller

Move up Delete Move down

Reflection

To be honest, I was nervous about this project. I have very informal coding experience and no circuit experience, so I wasn't sure how well it'd go.

Fortunately, I found the basics to be pretty accessible, particularly with IFTTT. I was disappointed my mic broke before I could document my laundry hack, but I was happy that I could pull together a new device without too much added work.

I enjoyed getting familiar with the fundamentals and 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