Belay on!

Problem:

In rock climbing, when ascending a natural rock face, rock climbers use a technique called lead climbing. This is different from toprope climbing, where the rope is already tethered to the top of the route. Here, the lead climber brings the rope up the rock surface with them.

(Source)

More details about lead climbing can be found here.

Due to the physical position of the belayer, it is incredibly tiring for them to continuously keep a lookout on the climber. Sometimes, this is even impossible if there are outcrops of rock that occludes the belayer’s line of sight.

There are some tools today such as belay glasses that try to relieve the neck strain of belayers, but it is still a tiring job and it’s incredibly easy to make a mistake, when you take your eyes off of the climber or look down for a break.

In fact, it is so tedious and strenuous that lots of pro climbers get into accidents and falls often while lead climbing. How can we provide visual feedback to help reduce incidence of accidents and injury?

Solution:

Creating a system of visual feedback where there’s an indicator signaling how high or low the tension is in the rope. Compared to regular toprope, there is little physical feedback on the belayer on how taut the lead climber’s rope actually is. By introducing more indicators on the belay device, the belayer will be more aware of the rope tension as this feedback will be visible within their line of sight, and on the belay device.

(Source)

Part 1: Preventing falling

(Source)

One of the greatest causes of accidents is slow or absent braking when the lead climber falls. At all times, except when letting in more rope, the belayer should apply friction to the right side of the belay device to act as an emergency brake. In this visual feedback system, if there is insufficient tension applied, a red light will start blinking. Once it is pulled taut enough to withstand a fall from the lead climber, it will stop blinking.

Part 2: Slack awareness

One of the other most important factors in lead climbing is providing the lead climber with the appropriate amount of slack. If it’s too little, they can’t stretch or move far enough to progress. If it’s too much, they run the risk of a highly injurious fall if they do end up slipping. By introducing a color indicator of the range of rope tension, we enable belayers to better monitor this more closely and make adjustments more quickly. As the tension moves low to high, the range is indicated on the row of lights.

Side view, for better view of colors in visual feedback:

Front view demo of the whole system:

Schematic:

Code:

#define belayLeft   1 //left pot
#define belayRight  0 //right pot

//to store tension on upward and downard tension on belay device
int upwardPull = 0;
int downwardPull = 0;

//LED pins in a row, left
int Blue1 = 3;
int Blue2 = 4;
int Green1 = 5;
int Green2 = 6;
int Yellow1 = 7;
int Yellow2 = 8;

//Blinking LED, right
int R1 = 9;

void setup() {
  Serial.begin(9600);

  pinMode(Blue1, OUTPUT);
  pinMode(Blue2, OUTPUT);
  pinMode(Green1, OUTPUT);
  pinMode(Green2, OUTPUT);
  pinMode(Yellow1, OUTPUT);
  pinMode(Yellow2, OUTPUT);
  pinMode(R1, OUTPUT);

  // put your setup code here, to run once:
  
}

void loop() {
  // read tension on both sides of belay device
  upwardPull = analogRead(belayLeft);
  downwardPull = analogRead(belayRight);

  //show range of tension in upwards belay
  if (upwardPull <= 50){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, LOW);
    digitalWrite(Green1, LOW);
    digitalWrite(Green2, LOW);
    digitalWrite(Yellow1, LOW);
    digitalWrite(Yellow2, LOW);
  }

  else if (upwardPull > 50 && upwardPull <= 100){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, HIGH);
    digitalWrite(Green1, LOW);
    digitalWrite(Green2, LOW);
    digitalWrite(Yellow1, LOW);
    digitalWrite(Yellow2, LOW);
  }

  else if (upwardPull > 100 && upwardPull <= 150){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, HIGH);
    digitalWrite(Green1, HIGH);
    digitalWrite(Green2, LOW);
    digitalWrite(Yellow1, LOW);
    digitalWrite(Yellow2, LOW);
  }

  else if (upwardPull > 150 && upwardPull <= 200){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, HIGH);
    digitalWrite(Green1, HIGH);
    digitalWrite(Green2, HIGH);
    digitalWrite(Yellow1, LOW);
    digitalWrite(Yellow2, LOW);
  }

  else if (upwardPull > 200 && upwardPull <= 220){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, HIGH);
    digitalWrite(Green1, HIGH);
    digitalWrite(Green2, HIGH);
    digitalWrite(Yellow1, HIGH);
    digitalWrite(Yellow2, LOW);
  }

  else if (upwardPull > 220){
    digitalWrite(Blue1, HIGH);
    digitalWrite(Blue2, HIGH);
    digitalWrite(Green1, HIGH);
    digitalWrite(Green2, HIGH);
    digitalWrite(Yellow1, HIGH);
    digitalWrite(Yellow2, HIGH);
  }


   //Red LED blinks if safety is not 'on'
   if (downwardPull < 100){
    digitalWrite(R1, HIGH);
    delay(100);
    digitalWrite(R1, LOW);
    delay(100);
   }else{
    digitalWrite(R1, LOW);
  }

  // debugging
//    Serial.print("   left side of belay device ");
    Serial.println(upwardPull);
//    Serial.print("   right side of belay device");
//    Serial.println(downwardPull);

}

 

Change of tune

Problem:
There are many factors that have to be considered in managing risk of contagion during the pandemic. One particularly difficult element to get a good gauge on and keep continuous track of is is how well ventilated the air around you is at any given time.

This is crucial and can counterbalance whether it is safe to remain where you are at any given point of time. It can significantly overcome the risk odds of being less than 6ft away from people, both indoors and outdoors.

Without ventilation, aerosols remain suspended in the air, becoming increasingly concentrated as time goes by. (Source)

Solution:
A concealed wind sensor housed in a lapel pin that gives you audio feedback about the air ventilation around you. Ideally, this would be able to connect to your phone or audio device wirelessly so that you can check on this discretely whenever needed.
To engage, push a button on the pin and the reading will be sent to your audio device.
Visual indicators:
For demo purposes, I have added LEDs to help visualize the invisible elements present in the solution.
White LED: visual feedback of wind sensor values changing
Green/yellow/red LED: indicator of what range of ventilation is safe or not.
Audio feedback:
I chose 3 different tunes for the 3 risk levels:
High risk – morse code for SOS
Medium risk – tense, suspenseful tune
Low risk – major key arpeggio as a simple, positive sounding indicator.
Demo:

At the start, the wind sensor reads a low level of ventilation, and starts playing the SOS tune. As the ventilation increases, it switches to the low risk tune of a major arpeggio. As that value falls slightly, it starts playing the suspenseful tune before reverting back to the major arpeggio as the values increase again.

Components:

  • 1x RGB Diffused Common Cathode
  • 3x LED (Red, Green, Yellow)
  • 1x button
  • 7x Resistor 220 ohm
  • Wind Sensor Rev. C
  • 35CSB speaker

Schematic:

Code:

/*************************************************
* Sound Sensor
*************************************************/
#define analogPinForRV    1   // blue jumper wire
#define analogPinForTMP   0   // yellow jumper wire

// to calibrate your sensor, put a glass over it, but the sensor should not be
// touching the desktop surface however.
// adjust the zeroWindAdjustment until your sensor reads about zero with the glass over it. 

const float zeroWindAdjustment =  .2; // negative numbers yield smaller wind speeds and vice versa.

int TMP_Therm_ADunits;  //temp termistor value from wind sensor
float RV_Wind_ADunits;    //RV output from wind sensor 
float RV_Wind_Volts;
unsigned long lastMillis;
int TempCtimes100;
float zeroWind_ADunits;
float zeroWind_volts;
float WindSpeed_MPH;

//LED Feedback
int redPin = 9; //Pin for the red RGB led pin
int greenPin = 10; //Pin for the green RGB led pin
int bluePin = 11; //Pin for the blue RGB led pin 

int writeValue_red; //declare variable to send to the red LED
int writeValue_green; //declare variable to send to the green LED
int writeValue_blue; //declare variable to send to the blue LED



/*************************************************
* Interrupt Button
*************************************************/
static const int togglePin = 5;
bool buttonState = false;
const bool isInterrupt = true;

/*************************************************
* Melodies
*************************************************/
#include "pitches.h"
int speakerPin = 8;

// notes in the major melody (9 notes):
int majorMelody[] = {
NOTE_C4, NOTE_D4,NOTE_G4, NOTE_C5, 0, NOTE_C4, NOTE_D4, NOTE_G4, NOTE_C5};

// note durations: 4 = quarter note, 8 = eighth note, etc.:
int majorNoteDurations[] = {
   4, 4, 4, 4, 4, 4, 4, 4, 4
};

// notes in the minor melody (9 notes):
int minorMelody[] = {
NOTE_FS4, NOTE_FS4, NOTE_FS4, NOTE_DS4, 0, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_CS4};
// note durations: 4 = quarter note, 8 = eighth note, etc.:

int minorNoteDurations[] = {
   8, 8, 8, 2, 4, 8, 8, 8, 2
};

// notes in morse code (11 notes):
int SOS[] = {
  NOTE_GS5, NOTE_GS5, NOTE_GS5, 0, NOTE_GS5, NOTE_GS5, NOTE_GS5, 0, NOTE_GS5, NOTE_GS5, NOTE_GS5
};

int SOSDurations[] = {
  8, 8, 8, 4, 2, 2, 2, 4, 8, 8, 8
};


/*************************************************
 * 
 * SETUP
 * 
*************************************************/

//void SwitchPressed(){
//  buttonState =! buttonState;
//}

void setup() {

  Serial.begin(57600);   // faster printing to get a bit better throughput on extended info
  // remember to change your serial monitor

  Serial.println("start");
  // put your setup code here, to run once:

  //   Uncomment the three lines below to reset the analog pins A2 & A3
  //   This is code from the Modern Device temp sensor (not required)
  pinMode(A2, INPUT);        // GND pin      
  pinMode(A3, INPUT);        // VCC pin
  digitalWrite(A3, LOW);     // turn off pullups

  //initialize button pin as input
//  pinMode(buttonPin, INPUT_PULLUP);

  //Risk feedback state
  int greenLED = 2;
  int yellowLED = 3;
  int redLED = 4;
  pinMode(greenLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(redLED, OUTPUT);

//  if (isInterrupt){
//      attachInterrupt(digitalPinToInterrupt(togglePin), SwitchPressed, RISING);    
//  }
  
}

void loop() {
  
/*************************************************
* Reading Wind Sensor
*************************************************/
  if (millis() - lastMillis > 200){      // read every 200 ms - printing slows this down further
    
    TMP_Therm_ADunits = analogRead(analogPinForTMP);
    RV_Wind_ADunits = analogRead(analogPinForRV);
    RV_Wind_Volts = (RV_Wind_ADunits *  0.0048828125);

    // these are all derived from regressions from raw data as such they depend on a lot of experimental factors
    // such as accuracy of temp sensors, and voltage at the actual wind sensor, (wire losses) which were unaccouted for.
    TempCtimes100 = (0.005 *((float)TMP_Therm_ADunits * (float)TMP_Therm_ADunits)) - (16.862 * (float)TMP_Therm_ADunits) + 9075.4;  

    zeroWind_ADunits = -0.0006*((float)TMP_Therm_ADunits * (float)TMP_Therm_ADunits) + 1.0727 * (float)TMP_Therm_ADunits + 47.172;  //  13.0C  553  482.39

    zeroWind_volts = (zeroWind_ADunits * 0.0048828125) - zeroWindAdjustment;  

    // This from a regression from data in the form of 
    // Vraw = V0 + b * WindSpeed ^ c
    // V0 is zero wind at a particular temperature
    // The constants b and c were determined by some Excel wrangling with the solver.
    
   WindSpeed_MPH =  pow(((RV_Wind_Volts - zeroWind_volts) /.2300) , 2.7265);   
   
//    Serial.print("  TMP volts ");
//    Serial.print(TMP_Therm_ADunits * 0.0048828125);
//    
//    Serial.print(" RV volts ");
//    Serial.print((float)RV_Wind_Volts);
//
//    Serial.print("\t  TempC*100 ");
//    Serial.print(TempCtimes100 );
//
//    Serial.print("   ZeroWind volts ");
//    Serial.print(zeroWind_volts);

    Serial.print("   WindSpeed MPH ");
    Serial.println((float)WindSpeed_MPH);

    lastMillis = millis();
  }

/*************************************************
* Wind sensor LED feedback
*************************************************/

  writeValue_red = (255./10.)*WindSpeed_MPH; //Calculate the value to write on the red LED (add point to change to float point)
  writeValue_green = (255./10.)*WindSpeed_MPH; //Calculate the value to write on the green LED
  writeValue_blue = (255./10.)*WindSpeed_MPH; ///Calculate the value to write on the blue LED
  
  analogWrite(redPin,writeValue_red); //write value to set the brightness of the red LED
  analogWrite(greenPin,writeValue_green); //write value to set the brightness of the green LED
  analogWrite(bluePin,writeValue_blue); //write value to set the brightness of the blue LED



/*************************************************
* State + Sound
*************************************************/

//if (buttonState == true){
//  

    if(WindSpeed_MPH <= 2){
    // turn red LED on:
    digitalWrite(4, HIGH);
    // turn the rest off:
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);

    // play SOS melody:
     for (int thisNote = 0; thisNote < 11; thisNote++) {
      int noteDuration = 1000/SOSDurations[thisNote];
      tone(8, SOS[thisNote],noteDuration);
      //pause for the note's duration plus 30 ms:
      delay(noteDuration +30);
      noTone(8);
    }
  }

    else if (WindSpeed_MPH >7) {
      //turn green LED on:
      digitalWrite(2, HIGH);
      // turn the rest off:
      digitalWrite(4, LOW);
      digitalWrite(3, LOW);

      //play major melody:
      for (int thisNote = 0; thisNote < 9; thisNote++) {
      int noteDuration = 1000/majorNoteDurations[thisNote];
      tone(8, majorMelody[thisNote],noteDuration);
      //pause for the note's duration plus 30 ms:
      delay(noteDuration +30);
      noTone(8);
    }
   }

    else {
      //turn yellow LED on:
      digitalWrite(3, HIGH);
      // turn the rest off:
      digitalWrite(2, LOW);
      digitalWrite(4, LOW);

      //play minor melody:
      for (int thisNote = 0; thisNote < 9; thisNote++) {
      int noteDuration = 1000/minorNoteDurations[thisNote];
      tone(8, minorMelody[thisNote],noteDuration);
      //pause for the note's duration plus 30 ms:
      delay(noteDuration +30);
      noTone(8);
      
    }
    }
//    }
//    else {
//      noTone(8);
//      //turn all LEDs off:
//      digitalWrite(3, LOW);
//      digitalWrite(2, LOW);
//      digitalWrite(4, LOW);
//    }
/*************************************************
* Wind sensor LED feedback on button press
*************************************************/
//buttonState = digitalRead(buttonPin);
//
//if (buttonState == HIGH){
//
//  if (flag == 0){
//    //light up white LED
//    analogWrite(redPin,writeValue_red); //write value to set the brightness of the red LED
//    analogWrite(greenPin,writeValue_green); //write value to set the brightness of the green LED
//    analogWrite(bluePin,writeValue_blue); //write value to set the brightness of the blue LED
//  flag = 1;
//  }
//
//  if (flag == 1){
//    //turn off white LED
//    analogWrite(redPin,0); //write value to set the brightness of the red LED
//    analogWrite(greenPin,0); //write value to set the brightness of the green LED
//    analogWrite(bluePin,0); //write value to set the brightness of the blue LED
//    flag = 0;
//  }
//}
//
//if (buttonState == HIGH){
//    //light up white LED
//    analogWrite(redPin,writeValue_red); //write value to set the brightness of the red LED
//    analogWrite(greenPin,writeValue_green); //write value to set the brightness of the green LED
//    analogWrite(bluePin,writeValue_blue); //write value to set the brightness of the blue LED
//}
//
//else if (buttonState == LOW){
//    //turn off white LED
//    analogWrite(redPin,0); //write value to set the brightness of the red LED
//    analogWrite(greenPin,0); //write value to set the brightness of the green LED
//    analogWrite(bluePin,0); //write value to set the brightness of the blue LED
//}

}

Reminder: include pitches.h for code to work

 

Are you prepared for the next couple hours weather?

Problem

With quarantine, I have not been leaving the house all that much, so I seem to have lost my intuition about temperature and my habit of always checking the weather in the morning. This has led me to be surprised by how hot/cold it gets if I’ve gone on a long walk or gone grocery shopping as well as when it starts raining before I’ve gotten home. I’ve found myself really cold in just a sweatshirt in the evening, hot when I wore thick sweatpants on a day that became unusually warm, and caught in the rain unprepared in the infrequent times I’ve been outside for an hour or two this semester.  This led me to the idea of a system that when I leave the house, would let me know about weather changes in the 2 following hours without bothering me.

Proposed Solution

To solve this problem, I propose a small device that can be placed on the wall near the front door that will detect when you leave the house and give notifications appropriate to the current weather and the changes. The opening of the door is detected with a magnetic reed switch.  Whether you are entering or exiting the house is decided based on if the PIR motion sensor detects motion right before the door opens. If you are entering the house, motion will be detected. Notifications will only be given when you are leaving the house, so when no motion is detected. This device uses an esp32 board (I chose the Adafruit Huzzah32) to get the current and hourly weather from the OpenWeather API over WiFi. The current temperature and weather condition as well as that of the next 2 hours are taken from the fetched information. If it will rain or snow, and it isn’t already raining or snowing, the buzzer will play a specific tone sequence 3 times as the door is opening. I chose a sequence that sounds to me a bit like “oh hooray” when it will snow because I love snow. If it will rain, I chose a more warning sound alert because it’s usually not fun to get caught in the rain. The main reason I chose to not give an alert if it will snow/rain when it already is is because you can clearly see what’s happening and should be prepared for it to keep raining/snowing. The buzzer was chosen rather than a speaker because it was loud enough to catch my attention easily, but unlike the speaker it isn’t loud enough to be annoying. I chose to have the LED strip light up to let you know it will be colder or hotter by 5 or more degrees Fahrenheit as that’s when the temperature change bothers me. Red corresponds to hotter and blue to colder. The LED strip will flash for 2 seconds once the door closes to get your attention and then for another 5 seconds it will stay that color so that you can still see the alert but not get annoyed by it as you are leaving. In the next section, you can see demo videos of the cases for this device.

Proof of Concept

Outside videos showing operation when set up:

Demo while leaving the house showing the snow and colder notifications.

Demo while entering the house, showing how there’s no notifications even though the temperature gets colder enough and it will snow.

Videos taken inside to show the different cases:

Demo showing how there are no notifications when temperature doesn’t change enough and it won’t snow or rain.

Demo showing when it just gets colder.

Demo showing when it just gets hotter.

Demo showing when it just will rain.

Demo showing when it just will snow.

Demo showing when it just will rain and is currently raining.

Changes for real implementation

Currently, my device is easily seen and looks bad especially because I had to use so much duct tape for things to stick. To fix this, I would use command strips instead of duct tape to attach everything to the door and wall. The wires for the magnetic reed switch would be all white to blend more. The main board part would be soldered together and put into a box then place under the decorative wreath.

In the final version, a rechargeable 9V battery would be stepped down to 5V would power the LED strip and PIR motion sensor rather than my uno plugged into my laptop which I used because my 9V battery was drained. Using a usb wall plug, I would power the esp32 board rather than my laptop’s port. The outlet my laptop is plugged into would be used for this.

I would run the LED strip wires across the roof of the porch and put the LED strip where the green circle is. This way, it would be where you face while leaving the house and is in the line of sight for going down the porch stairs.

Schematic:

Code:

Note: You will have to enter in your own WiFi information as well as API key- I don’t want to just broadcast that.

//used this tutorial for getting weather: https://techtutorialsx.com/2018/03/17/esp32-arduino-getting-weather-data-from-api/
#include <WiFi.h>
#include <HTTPClient.h>
const char* ssid = "YOUR WIFI NAME";
const char* password =  "YOUR WIFI PASSWORD";

const String endpoint = "https://api.openweathermap.org/data/2.5/onecall?lat=40.445227&lon=-79.934243&exclude=minutely,daily,alerts&units=imperial&appid=";//CHANGE TO LOCATION YOU WANT DATA FROM
const String key = "YOUR UNIQUE KEY";

const int doorSwitchPin = 14;
int justOpened = 0;
int foundWeather = 0;
//const int LEDpin=12;
#include <NeoPixelBus.h>
const int LEDstripPin = 12;
const int numLEDs = 10;
NeoPixelBus<NeoGrbFeature, Neo800KbpsMethod> strip(numLEDs, LEDstripPin);
long startTime;

int hotter = 0;
int colder = 0;
int currentlyRaining = 0;
int currentlySnowing = 0;
int willRain = 0;
int willSnow = 0;
int rainWarning = 0;
int snowWarning = 0;
int maskWarning = 0;
int haveMask = 0;
String content;
#include <Tone32.h>

#define BUZZER_PIN A0
#define BUZZER_CHANNEL 0


const int PIRpin = 27;
int pirVal;

void pirISR() {
  pirVal = digitalRead(PIRpin);
}

//RFID stuff mainly from this tutorial https://randomnerdtutorials.com/security-access-using-mfrc522-rfid-reader-with-arduino/
//#include <SPI.h>
//#include <MFRC522.h>
//
//#define SS_PIN 23
//#define RST_PIN 15
//MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.

void setup() {

  Serial.begin(115200);
  //  SPI.begin();      // Initiate  SPI bus
  //  mfrc522.PCD_Init();   // Initiate MFRC522
  pinMode(doorSwitchPin, INPUT);
  pinMode(PIRpin, INPUT);
  attachInterrupt(digitalPinToInterrupt(PIRpin), pirISR, CHANGE);
  //pinMode(LEDpin, OUTPUT);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }

  Serial.println("Connected to the WiFi network");
  // this resets all the neopixels to an off state
  strip.Begin();
  strip.Show();
}

void loop() {
  if ((WiFi.status() == WL_CONNECTED)) { //Check the current connection status
    HTTPClient http;
    if (digitalRead(doorSwitchPin) == 0) {//door opened
      //added measure so lights off when the door is opened, will immediately turn of lights if you open it while they are on
      for (int i = 0; i < numLEDs; i = i + 1) {
        strip.SetPixelColor(i, RgbColor(0, 0, 0));
      }
      strip.Show();
      if (pirVal == 0) { //no motion detected at door near knob outside, so ur opening from inside
        //        if (haveMask == 0) { // Look for new cards
        //          if ( ! mfrc522.PICC_IsNewCardPresent())
        //          {
        //            //return;
        //          }
        //          // Select one of the cards
        //          if ( ! mfrc522.PICC_ReadCardSerial())
        //          {
        //            //return;
        //          }
        //        }
        //        //Show UID on serial monitor
        //        // Serial.print("UID tag :");
        //        content = "";
        //        byte letter;
        //        for (byte i = 0; i < mfrc522.uid.size; i++)
        //        {
        //          //          Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
        //          //          Serial.print(mfrc522.uid.uidByte[i], HEX);
        //          content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
        //          content.concat(String(mfrc522.uid.uidByte[i], HEX));
        //        }
        //        content.toUpperCase();
        //
        //        if (content.substring(1) == "ED E4 86 B9" || content.substring(1) ==  "9D 65 7D B9" ) {//change here the UID of the card/cards that you want to give access
        //          int haveMask = 1;
        //        }
        //        else { //dont have mask
        //          if (maskWarning == 0) {
        //            for (int count = 0; count < 4; count++) {
        //              tone(BUZZER_PIN, NOTE_D4, 500, BUZZER_CHANNEL);
        //  noTone(BUZZER_PIN, BUZZER_CHANNEL);
        //  tone(BUZZER_PIN, NOTE_C4, 500, BUZZER_CHANNEL);
        //  noTone(BUZZER_PIN, BUZZER_CHANNEL);
        //            }
        //            maskWarning = 1; //been warned
        //          }
        //        }
        if (foundWeather == 0) {//havent calculated the weather for this opening yet
          // Serial.println("calculating");
          http.begin(endpoint + key); //Specify the URL
          int httpCode = http.GET();  //Make the request

          if (httpCode > 0) { //Check for the returning code

            String payload = http.getString();
            int first1 = payload.indexOf("temp");//gives index of the t
            int start1 = first1 + 6;//add indexso that I'm at the number
            int end1 = payload.indexOf(',', start1);
            Serial.println(payload);
            //Serial.println(start1);
            float currentTemp = payload.substring(start1, end1).toFloat();//making string into float so that I can do math with it

            int first2 = payload.indexOf("temp", end1);
            int start2 = first2 + 6;
            int end2 = payload.indexOf(',', start2);
            float hrOneTemp = payload.substring(start2, end2).toFloat();

            int first3 = payload.indexOf("temp", end2);
            int start3 = first3 + 6;
            int end3 = payload.indexOf(',', start3);
            float hrTwoTemp = payload.substring(start3, end3).toFloat();

            Serial.print("Current temp: ");
            Serial.print(currentTemp);
            Serial.print("\t");
            Serial.print("Temp in 1 hr: ");
            Serial.print(hrOneTemp);
            Serial.print("\t");
            Serial.print("Temp in 2 hrs: ");
            Serial.println(hrTwoTemp);
            if (((hrOneTemp - currentTemp) > 5) || ((hrTwoTemp - currentTemp) > 5)) { //would've been 5 but not fluctuating much at all recently
              hotter = 1;
            }
            else {
              hotter = 0;
            }
            if (((currentTemp - hrOneTemp) > 5) || ((currentTemp - hrTwoTemp) > 5)) { //would've been 5 but not fluctuating much at all recently
              colder = 1;
            }
            else {
              colder = 0;
            }
            int first4 = payload.indexOf("temp", end3);//just using to know around where hour 3 is
            int checkRain = payload.indexOf("Rain");
            if (checkRain != -1) { //means doesn't rain at all in huge data set
              if (checkRain < first2) {
                currentlyRaining = 1;
                willRain = 0; //dont care if it rains later as can already see it's raining
              }//don't bother finding index of another rain bc if it's already raining don't need to see if it'll rain in next 2 hours
              else if (checkRain < first3) {
                willRain = 1; //will rain in an hr
              }
              else if (checkRain < first4) {
                willRain = 1; //will rain in 2 hours
              }
            }
            else {
              willRain = 0;
            }
            int checkSnow = payload.indexOf("Snow");
            if (checkSnow != -1) {
              if (checkSnow < first2) {
                currentlySnowing = 1;
                willSnow = 0;
              }
              else if (checkSnow < first3) {
                willSnow = 1;
              }
              else if (checkSnow < first4) {
                willSnow = 1;
              }
            }
            else {
              willSnow = 0;
            }
            willRain = 1;
            Serial.print("Currently raining: ");
            Serial.print(currentlyRaining);
            Serial.print("\t");
            Serial.print("Will rain: ");
            Serial.println(willRain);
            Serial.print("Currently snowing: ");
            Serial.print(currentlySnowing);
            Serial.print("\t");
            Serial.print("Will snow: ");
            Serial.println(willSnow);
            if (willRain) {
              if (rainWarning == 0) {
                for (int count = 0; count < 4; count++) {//play sequence 3x while door is being closed/your just stepping outside
                  tone(BUZZER_PIN, NOTE_C4, 100, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                  tone(BUZZER_PIN, NOTE_A4, 200, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                  tone(BUZZER_PIN, NOTE_B4, 200, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                }
                rainWarning = 1;//so warning doesn't just keep playing if door is open
              }
            }
            if (willSnow) {
              if (snowWarning == 0) {
                for (int count = 0; count < 4; count++) {
                  tone(BUZZER_PIN, NOTE_D4, 100, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                  tone(BUZZER_PIN, NOTE_E4, 500, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                  tone(BUZZER_PIN, NOTE_C4, 300, BUZZER_CHANNEL);
                  noTone(BUZZER_PIN, BUZZER_CHANNEL);
                }
                snowWarning = 1;
              }
            }
          }

          else {
            Serial.println("Error on HTTP request");
          }

          http.end(); //Free the resources
          foundWeather = 1;
        }
      }
    }
    //}
    else {//door closed again
      if (foundWeather == 1) {
        startTime = millis();
        //resetting the variables above
        rainWarning = 0;
        snowWarning = 0;
        maskWarning = 0;
        haveMask = 0;
        content = "";
      }
      foundWeather = 0;


      if (hotter) {
        if (millis() - startTime < 2000) { //flash to get attention
          static int blinkStart = millis();
          for (uint16_t i = 0; i < numLEDs; i++) {//this rotates through each LED on the strip so that each one will be red
            byte x = millis() - 20 * i;
            strip.SetPixelColor(i, RgbColor(255 - x, 0, 0));
          }
          strip.Show();
          if (millis() - blinkStart >= 10) {
            for (uint16_t i = 0; i < numLEDs; i++) {
              strip.SetPixelColor(i, RgbColor(0, 0, 0));
            }
            strip.Show();
            blinkStart = millis();
          }
        }
        else if (millis() - startTime < 7000) {//stays on just lights as attention probably already caught and dont want to annoy
          for (uint16_t i = 0; i < numLEDs; i++) {
            byte x = millis() - 20 * i;
            strip.SetPixelColor(i, RgbColor(255 - x, 0, 0));
          }
        }
        else {
          for (int i = 0; i < numLEDs; i = i + 1) {
            strip.SetPixelColor(i, RgbColor(0, 0, 0));
          }
          strip.Show();
        }
      }
      else if (colder) {
        if (millis() - startTime < 2000) { 
          static int blinkStart = millis();
          for (uint16_t i = 0; i < numLEDs; i++) {
            byte x = millis() - 20 * i;
            strip.SetPixelColor(i, RgbColor(0, 0, 255 - x));
          }
          strip.Show();
          if (millis() - blinkStart >= 10) {
            for (uint16_t i = 0; i < numLEDs; i++) {
              strip.SetPixelColor(i, RgbColor(0, 0, 0));
            }
            strip.Show();
            blinkStart = millis();
          }
        }
        else if (millis() - startTime < 7000) {
          for (uint16_t i = 0; i < numLEDs; i++) {
            byte x = millis() - 20 * i;
            strip.SetPixelColor(i, RgbColor(0, 0, 255 - x));
          }
        }
        else {
          for (int i = 0; i < numLEDs; i = i + 1) {
            strip.SetPixelColor(i, RgbColor(0, 0, 0));
          }
          strip.Show();
        }
      }
    }
  }
}

Notes on taking project further and functioning that was decided against

  • The idea of having an RFID scanner so that notifications are only given when you aren’t prepared is really interesting and would add great functionality, but doesn’t work well with this project. The RFID scanner I have took too long to read the card and held up the entire system; it took long enough that you could already make it to the stairs before a notification was given. Additionally, the card/tag had to be touching the scanner which isn’t realistic for someone leaving the house to do. Finally, it can’t read multiple cards right next to each other. The first of these problems could be fixed with better equipment, but I don’t think the other two would get solved. If someone fixed these issues and wanted to make my project, especially more commercial, the add-ons would be that the clothes and items that pertain to certain type of weather (ie sweatshirt, raincoat, boots, gloves, etc) could be scanned on the way out. Multiple tags can be used for the same category and the tags could be small and machine washable. Similar to this, in the age of covid, masks could be checked for and if you don’t have one, be warned with an alarm sound. Moreover, our school cards are RFID cards, so I could have set it to react according to who is leaving the house or even only just for me. To really expand, a To-do list could be linked via the internet and if you leave close to the time of grocery shopping, you could get a notification if you don’t have reusable bags.
  • Instead of specific sound sequences, I tried to use the TTS esp library with a speaker and amplifier circuit. This is loud enough with the amplifier circuit, however, it isn’t very understandable. I wanted it to say, rain, snow, and mask (with the RFID implemented but again it didn’t work fast enough). Even changing the text given to try and make it sound better by spelling more like pronunciation didn’t help much.
  • Something relatively easy to do with IFTTT is to send a text message when certain criteria are met. I could have had a text message to me if it was going to be colder, hotter, rain, or snow. I decided against this because it would only really make sense if who was leaving was detected and free accounts only have 3 applets included so I didn’t want to use another on this especially since for me I probably wouldn’t even look at or notice that notification until I’m pretty far away.

Notes about using the esp32 board

In general, it takes much longer to compile and upload to the board than it did for the uno.

Certain libraries that work with the uno don’t work with this and you need to download different ones in general or the same ones modified to work with esp32s.

  • I needed to use the Tone32 library instead of regular one.
  • The PololuLedStrip library is incompatible and so I instead used NeoPixelBus.
  • Not for this project, but for the other one I’m working on, I needed to use download an esp servo library and still included Servo.h like usual.

Interactive paper menu interactions

As technology advances, many interactions are drastically changing. When I came back to China, I was shocked by how mobile ordering in restaurants is widely adopted. It went from ordering with a server, to ordering using a tablet/ipad, to a table of people ordering from the same phone, to now where everyone can contribute to the same order using their own phone. Just like many people who prefer reading a paper book, I really enjoyed flipping through menus at restaurants.

However, we cannot ignore the benefit of having electronic orders: the order goes directly to the kitchen and all orders are automatically  stored digitally. To combine the paper feel of the menu and the benefit of having a digital menu, this project explores 3 ways of interactions that can be used in a interactive paper menu using paper circuits.

The initial goal was to have a full menu, but I realized it was too ambitious so I scaled down the project, but I did make these designs for a imaginary make-your-own burger restaurant. I will discuss more about the original design later.

So for this project, what I ended up doing was 3 different interactions:

    • presses (equivalent to a button)
    • slider (equivalent to a linear potentiometer)
    • wheel (equivalent to a circular potentiometer)

I won’t include a schematic here because paper circuits are quite different from using wires and parts. And in fact, the only materials I used here is:

    • an arduino uno

      Conductive tape, resistors, and SMD LEDs
    • wires to connect the paper circuit to arduino
    • solder & soldering iron to connect wires&resistors&LEDs to paper circuit
    • conductive tape (conductive on both sides, which made the fabrication much easier!)
    • resistors
    • SMD LEDs
    • paper
    • tapes

Here is what the paper circuit initially looked like for testing. On the top we have the wheel, then the slider,and those taped cardboard squares are presses.

First, let’s look at the wheel. 3 resistors(for 4 segments) are used, and they are connected in sequence with one end to 5v and one end to ground. We use an analog pin(connection to the analog pin not included here) and use the read value to determine which segment of the wheel is in contact with pin.

Then, we have the slider. Similar to the wheel, the wirings of it is exactly the same, except for they are placed linearly on paper. We used 4 resistors here because  we have 5 segments.

Presses are simply buttons. On the paper, we have one tape connected to the ground, and one tape connected to a digital pin (with internal pullup resistor). We use non-conductive tape to tape these “buttons” on top gap between the ‘ground’ tape and ‘digital pin’ tape. When the ‘button’ is pressed, the conductive part of the button connects the ‘ground’ tape and ‘digital pin’ tape, and thus makes the value change for the digital pin read.

Working with conductive tape was definitely more tedious and involves more planning compared with using wires, but one thing I found convenient was that to make  2 pieces of overlapping conductive tape non-conductive with each other, simply place a piece of non-conductive tape between the two, which is why in some of my photos, you see traces with different purposes “overlap” with each other.

In the image below, we added a block of conductive tape for the wheel, and a line for the slider, they are connected to the analog pins that read the values.  The 2 pieces on the right are used to create connections between these newly added circuits and the ones in the previous image.

So that was the first layer of the circuit, I call them input layer. Now let’s look a the second layer, the output(LEDs) layer. Each LED is wired to a digital pin with 220 ohms resistors in between and the other side to ground.

Then I connected the two layers by taping them together.

And finally, I put the graphic layer on the top. Notice the two pieces coming out of the graphic layer, they are our means of interactions. And they connect the layers simply by going through the papers.

So before this final version of the project, I tried a variety of things.

Here are some initial playing with the paper circuit. On the top left, I tried using graphite pencil marks as resistors, while it works, I thought it was too much trouble to make it as robust as I would like.

Below was my attempt to use a single analog pin to read 15 button/presses inputs. While it worked when I tested with tactile buttons, the readings again was not robust enough for the effect I needed.

The interaction I originally envisioned was that we have 2 wheels, a slider, and 16 presses on the right. And as things are being selected, the corresponding part on the burger gets lighted up. And once all the parts are lighted up, the order is ready to be completed. I gave up doing this when I realized that I don’t have enough digital pins, nor does the analog reading method works.

 

 

 

 

The main thing I struggled with was robust connections and readings, so I got lots of fuzzy readings that can’t just be fixed from the software side. For future works, getting an arduino mega with more pins would open up a lot more possibilities, and also some explorations in how to have robust connections using paper circuits.

#include <Bounce2.h>

const int WHEELPIN = A2;
const int WHEELLENGTH =4;
const int WHEELTHRESHOLD[] = {170, 512, 853, 1023};
const char *WHEELNAME[] = {"ciabatta", "lettuce wrap", "whole wheat", "brioche"};
char *bunselection = "none";

const int SLIDERPIN = A3;
const int SLIDERLENGTH = 5;
const int SLIDERTHRESHOLD[] = {1023, 897, 644, 340, 130};
const char *SLIDERNAME[] = {"well done", "medium well", "medium", "medium rare", "rare"};
char *cookselection = "none";

const int RESETBUTTON = 3;

const int TOPPINGSNUM = 4;
const int TOPPINGSPIN[] = {7, 6, 5, 4};

const int LEDNUM = 5;
const int LEDPINS[] = {13, 12, 11, 10, 9};
Bounce buttons[] = {Bounce(), Bounce(), Bounce(), Bounce(), Bounce()};
Bounce b = Bounce();

const char *TOPPINGNAME[] = {"red onion", "tomato",
                     "lettuce", "pickels"};
bool toppingsSeletion[] = {false, false, false, false};

void reset() {
  for (int i=0; i< TOPPINGSNUM; i++) {
    toppingsSeletion[i] = false;
  }
  bunselection = "none";
  cookselection = "none";
}
void setup() {
  Serial.begin(9600);
  for (int i=0; i< TOPPINGSNUM; i++) {
    buttons[i].attach (TOPPINGSPIN[i] , INPUT_PULLUP);
    buttons[i].interval(100);
  }
  buttons[TOPPINGSNUM].attach (RESETBUTTON , INPUT_PULLUP);
}

void loop() {
  // check for reset 
  buttons[TOPPINGSNUM].update();
  if (buttons[TOPPINGSNUM].fell()) {
    Serial.println("reset");
    reset();
  }

  // check for toppings selection
  for (int i=0; i< TOPPINGSNUM; i++) {
    buttons[i].update();
    if (buttons[i].fell()) {
      toppingsSeletion[i] = (!toppingsSeletion[i]);
      Serial.print(TOPPINGNAME[i]);
      if (toppingsSeletion[i]) {
        Serial.println(" is selected");
      }
      else {
        Serial.println(" is no longer selected");
      }
    }
  }

  // check for wheel
  int wheelVal = analogRead(WHEELPIN);
  for (int i=0; i< WHEELLENGTH; i++) {
    if (wheelVal <= WHEELTHRESHOLD[i]) {
      if (WHEELNAME[i] != bunselection) {
        bunselection = WHEELNAME[i];
        Serial.print("bun selection changed to: ");
        Serial.println(bunselection);
      }
      break;
    }
  }

  int sliderVal = analogRead(SLIDERPIN);
  for (int i=SLIDERLENGTH-1;  i>= 0; i--) {
    if (sliderVal <= SLIDERTHRESHOLD[i]) {
      if (SLIDERNAME[i] != cookselection) {
        cookselection = SLIDERNAME[i];
        Serial.print("cook changed to: ");
        Serial.println(cookselection);
        for (int j=0; j<LEDNUM; j++) {
          digitalWrite(LEDPINS[j], LOW);
        }
        for (int j=0; j<=i; j++) {
          digitalWrite(LEDPINS[j], HIGH);
        }
      }
      break;
    }
  }
}

 

 

Should I stay or should I go?

Problem:

There are many factors that have to be considered in managing risk of contagion during the pandemic. These are not straightforward, and can vary wildly depending on the context and combination of variables. Constantly trying to analyze these can cause fatigue, anxiety and unnecessary worry about perceived risks.

One particularly difficult element to get a good gauge on whether it is safe to remain indoors in a particular space. While maintaining 6ft of distance is still a good rule of thumb, it doesn’t always guarantee low risk.

This can be counterbalanced by other risk factors, such as ventilation and speaking volume. Risky activity such as singing generates significantly more droplets and aerosols that increases infection risks significantly, even when keeping a distance of 6ft.

Often, in an enclosed space, even when in individuals are in close proximity, a powerful HVAC system is circulating the air can prevent significant spreading. For example, when looking at transmission patterns in airplanes, only a few individuals sitting directly next to, in front of and behind Patient Zero were infected. Others remained safe, even though they remained in the same (relatively small) enclosed area for a significant amount of time.

This further complicated by having to consider the volume of indoor space – how risky these factors are varies considerably based on that as well.

Without ventilation, aerosols remain suspended in the air, becoming increasingly concentrated as time goes by. (Source)

Solution:

Lots of these factors, such as ventilation and speaking volume, are invisible and hard to keep track to begin with. Compared to distance from the next person, it’s really difficult for the average person to estimate what’s safe and what’s not.

It is even more challenging and stressful to calibrate these against dynamic changes from people coming and leaving, and the type of activity or behavior they choose when in said space.

By developing a system that balances all these factors and aggregates an overall risk grade that is displayed in a public space, it’s much easier for incoming and outgoing individuals to gauge their risk and exposure, and take the necessary precautions immediately.

As the number of people increase, the tradeoff between ventilation and noise level changes. We monitor these different axes with a wind sensor, a sound sensor and an ultrasonic sensor.

Components:

  • 1x HC-SR04 ultrasonic sensor
  • 1x RGB Diffused Common Cathode
  • 3x LED (Red, Green, Yellow)
  • 6x Resistor 220 ohm
  • Wind Sensor Rev. C
  • 1x LCD1602 Module
  • Sound sensor (replaced by potentiometer)

Wind sensor

The wind sensor gives us an approximation of the rate of airflow, and thus some insight into the amount of ventilation that a space has.

 

Ultrasonic sensor

Using two ultrasonic sensors, we can keep count of how many people are in the room at any one time.

 

Sound sensor

The decibel level can give us an approximation of how loudly people in the room are speaking (and thus how likely they are to expel aerosols in the air). A library is ~40dB, and a cafe is ~80dB. I will be substituting this value with a potentiometer for demo purposes, with a range of 1-100 to represent dB levels.

Safety rating

Keeping track of all this and displaying this information to the individuals in a space is an overall safety rating that indicates the recommended course of action to remain safe.

 

What should you do, and when?

When the number of people in a room is small, the safety rating remains green regardless of how well ventilated and how loud people are.

But, if enough people gather, the safety rating will turn red.

In this case, you might choose not to enter the room, and keep walking. If you do need to be present, there are a few things you can do to improve the situation.

Reducing speaking levels and ventilation levels can shift the safety ratings. Depending on the extent of how much each of these fluctuate and in what direction, the overall effect could be either an increase or decrease in risk levels.

Another way to improve the safety rating is to just decrease the total number of people in a space.

If the safety rating does not change after making these adjustments, it’s a sign that you should leave in order to be safe.

Schematic:

Code:

/*************************************************
* Ultrasonic sensor + LCD screen
*************************************************/
#include <Wire.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
#define trigPin 10
#define echoPin 9

int counter = 0;
int currentState1 = 0;
int previousState1 = 0;
int currentState2 = 0;
int previousState2 = 0;
int inside = 0;
int outside = 0;

/*************************************************
* Wind Sensor
*************************************************/
#define analogPinForRV    1   // blue jumper wire
#define analogPinForTMP   0   // yellow jumper wire

// to calibrate your sensor, put a glass over it, but the sensor should not be
// touching the desktop surface however.
// adjust the zeroWindAdjustment until your sensor reads about zero with the glass over it. 

const float zeroWindAdjustment =  .2; // negative numbers yield smaller wind speeds and vice versa.

int TMP_Therm_ADunits;  //temp termistor value from wind sensor
float RV_Wind_ADunits;    //RV output from wind sensor 
float RV_Wind_Volts;
unsigned long lastMillis;
int TempCtimes100;
float zeroWind_ADunits;
float zeroWind_volts;
float WindSpeed_MPH;

//LED Feedback
int redPin = A4; //Pin for the red RGB led pin
int greenPin = A3; //Pin for the green RGB led pin
int bluePin = A2; //Pin for the blue RGB led pin 

int writeValue_red; //declare variable to send to the red LED
int writeValue_green; //declare variable to send to the green LED
int writeValue_blue; //declare variable to send to the blue LED



/*************************************************
* Sound sensor
*************************************************/
#define soundSensorPin  5
int soundSensor = 0;
bool soundRisk = false;

/*************************************************
* Aggregated risk
*************************************************/
int riskLevel = 0;
int greenLED = 6;
int yellowLED = 7;
int redLED = 8;

/*************************************************
 * 
 * SETUP
 * 
*************************************************/

void setup(){
  Serial.begin (57600);

  //Ultrasonic sensor + LCD
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  lcd.begin(16,2);

  //wind sensor
  Serial.println("start");
  //   Uncomment the three lines below to reset the analog pins A2 & A3
  //   This is code from the Modern Device temp sensor (not required)
  pinMode(A2, INPUT);        // GND pin      
  pinMode(A3, INPUT);        // VCC pin
  digitalWrite(A3, LOW);     // turn off pullups

  //Risk feedback state
  int greenLED = 6;
  int yellowLED = 7;
  int redLED = 8;
  pinMode(greenLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  
}

void loop(){

/*************************************************
* Ultrasonic sensor + LCD screen
*************************************************/
//setting up LCD screen display
lcd.setCursor(0, 0);
lcd.print("IN: ");
lcd.setCursor(7, 0);
lcd.print("Wind: ");
lcd.setCursor(0, 1);
lcd.print("OUT: ");
lcd.setCursor(7, 1);
lcd.print("Total: ");
  
//sending ping + calculating distance using ultrasonic sensor
long duration;
float distance;
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 29.1;

//going inside
if (distance<= 9){
  currentState1 = 1;
}
else {
  currentState1 = 0;
}

delay(100);

if(currentState1 != previousState1){
  if(currentState1 == 1){
    counter = counter + 1;
    inside = inside + 1;
    //update LCD screen
    lcd.setCursor(14, 1);
    lcd.print(counter);
    lcd.setCursor(4, 0);
    lcd.print(inside);
  }
  }

//returning outside
  if (distance > 14 && distance <=30){
    currentState2 = 1;
  }
  else {
    currentState2 = 0;
  }
  delay(100);
  
  if(currentState2 != previousState2){
    if(currentState2 == 1){
      counter = counter - 1;
      outside = outside + 1;
      //update LCD screen
      lcd.setCursor(14, 1);
      lcd.print(counter);
      lcd.setCursor(5, 1);
      lcd.print(outside);
    }
  }

//keeping tally based on   
    Serial.print("   IN:");
    Serial.println((float)inside);

    Serial.print("   OUT:");
    Serial.println((float)outside);

    Serial.print("   TOTAL INSIDE:");
    Serial.println((float)counter);
    
//debugging
//    Serial.println(duration);
//    Serial.println(duration/2);
//    Serial.println((duration/2) / 29.1);


/*************************************************
* Wind Sensor
*************************************************/
  if (millis() - lastMillis > 200){      // read every 200 ms - printing slows this down further
    
    TMP_Therm_ADunits = analogRead(analogPinForTMP);
    RV_Wind_ADunits = analogRead(analogPinForRV);
    RV_Wind_Volts = (RV_Wind_ADunits *  0.0048828125);

    // these are all derived from regressions from raw data as such they depend on a lot of experimental factors
    // such as accuracy of temp sensors, and voltage at the actual wind sensor, (wire losses) which were unaccouted for.
    TempCtimes100 = (0.005 *((float)TMP_Therm_ADunits * (float)TMP_Therm_ADunits)) - (16.862 * (float)TMP_Therm_ADunits) + 9075.4;  

    zeroWind_ADunits = -0.0006*((float)TMP_Therm_ADunits * (float)TMP_Therm_ADunits) + 1.0727 * (float)TMP_Therm_ADunits + 47.172;  //  13.0C  553  482.39

    zeroWind_volts = (zeroWind_ADunits * 0.0048828125) - zeroWindAdjustment;  

    // This from a regression from data in the form of 
    // Vraw = V0 + b * WindSpeed ^ c
    // V0 is zero wind at a particular temperature
    // The constants b and c were determined by some Excel wrangling with the solver.
    
   WindSpeed_MPH =  pow(((RV_Wind_Volts - zeroWind_volts) /.2300) , 2.7265);   

    
//debugging   
//    Serial.print("  TMP volts ");
//    Serial.print(TMP_Therm_ADunits * 0.0048828125);
//    
//    Serial.print(" RV volts ");
//    Serial.print((float)RV_Wind_Volts);
//
//    Serial.print("\t  TempC*100 ");
//    Serial.print(TempCtimes100 );
//
//    Serial.print("   ZeroWind volts ");
//    Serial.print(zeroWind_volts);

    Serial.print("   WindSpeed MPH ");
    Serial.println((float)WindSpeed_MPH);

    lastMillis = millis();

    lcd.setCursor(13, 0);
    lcd.print(WindSpeed_MPH);
  }

/*************************************************
* Wind sensor LED feedback
*************************************************/

  writeValue_red = (255./10.)*WindSpeed_MPH; //Calculate the value to write on the red LED (add point to change to float point)
  writeValue_green = (255./10.)*WindSpeed_MPH; //Calculate the value to write on the green LED
  writeValue_blue = (255./10.)*WindSpeed_MPH; ///Calculate the value to write on the blue LED
  
  analogWrite(redPin,writeValue_red); //write value to set the brightness of the red LED
  analogWrite(greenPin,writeValue_green); //write value to set the brightness of the green LED
  analogWrite(bluePin,writeValue_blue); //write value to set the brightness of the blue LED



/*************************************************
* Sound sensor
*************************************************/
int soundSensor = analogRead(soundSensorPin);

//assuming that there are two main buckets of sound levels - one is low, which conversational and not risky, and the other is high, such as singing, which is risky)
if (soundSensor >= 100){
  soundRisk = true;
}
  else {
    soundRisk = false;
  }

Serial.println(soundSensor);
Serial.println(soundRisk);

/*************************************************
* States + risk level display
*************************************************/

//small group
if (counter <= 3) {
  //sound and ventilation doesn't matter
  riskLevel = 0;  
}

//medium group
else if (counter > 3 && counter <=5){
  //sound risk is high, ventilation needs to be high
  if (soundRisk == true){
    if (WindSpeed_MPH >= 10){
      riskLevel = 0;
    } else if (WindSpeed_MPH < 10 && WindSpeed_MPH >= 7){
      riskLevel = 1;
    } else if (WindSpeed_MPH < 7){
      riskLevel = 2;
    }
    
  //sound risk is low, ventilation can be lower
  } else if (soundRisk == false){
      if (WindSpeed_MPH >= 7){
        riskLevel = 0;
      } else if (WindSpeed_MPH < 7 && WindSpeed_MPH >=2){
        riskLevel = 1;
      } else if (WindSpeed_MPH < 2){
        riskLevel = 2;
      }
  }
  
  //
}

//big group
else if (counter > 5){
  //sound risk is high, ventilation needs to be high
  if (soundRisk == true){
    if (WindSpeed_MPH >= 20){
      riskLevel = 0;
    }
    if (WindSpeed_MPH >= 10 && WindSpeed_MPH < 20){
      riskLevel = 1;
    } else if (WindSpeed_MPH <10){
      riskLevel = 2;
    }
  //sound risk is low, ventilation can be lower
  } else if (soundRisk == false){
    if (WindSpeed_MPH >= 12){
      riskLevel = 0;
    } else if (WindSpeed_MPH >= 8 && WindSpeed_MPH > 5){
      riskLevel = 1;
    } else if (WindSpeed_MPH <= 5){
      riskLevel = 2;
    }
  }
}

/*************************************************
* Overall risk level display
*************************************************/

if (riskLevel == 0){
  //Low risk
  //turn green LED on
  digitalWrite(greenLED, HIGH);
  //turn the rest off
  digitalWrite(redLED, LOW);
  digitalWrite(yellowLED, LOW);
}

else if (riskLevel == 1){
  //Medium risk
  //turn yellow LED on
  digitalWrite(yellowLED, HIGH);
  //turn the rest off
  digitalWrite(redLED, LOW);
  digitalWrite(greenLED, LOW);
}

else if (riskLevel == 2){
  //High risk
  //turn red LED on
  digitalWrite(redLED, HIGH);
  //turn the rest off
  digitalWrite(yellowLED, LOW);
  digitalWrite(greenLED, LOW);
}

}

Reflections on implementation

There are a few things which I tried and did not turn out so well for the prototype. For starters, I had initially attempted to operationalize the graph diagram I had drawn earlier indicating the relationship between sound volumes and ventilations. Not only were the resultant numbers difficult to predict and thus challenging to show in a demo, sound generally clusters around two median values – loud, or not too loud. Instead of a continuous range, I went ahead and made the sound value a boolean instead. Actual implementation of this would also require a much more nuanced look at the relationship between these variables as well as the risk tradeoffs along a continuum, unlike the buckets that I had created to assist accuracy in the demo.

There were also some unpredictability in the ultrasonic sensor’s readings and counting of people – on occasion, it would double or even triple count, while on others it missed it totally. This challenged the reproducibility of the demo. If this were to be implemented in real life, much more robust software would be needed in order to provide an accurate estimate of the number of people in the room.

I’m glad that in my second iteration of the circuits and code I was able to fit everything onto a single breadboard, as it made it much easier to see what was happening or changing altogether at once.

Growing this project further

If I had had more time, I would have liked to delve more into strategies in responsive architecture to help individuals respond more appropriately to the risk level. For example, if this was a public area such as an indoor mall, perhaps  public seating can transform to become more hostile to discourage loitering, or eliminate it by disappearing altogether.

One can imagine the benches shape-shifting into something uncomfortable. The example below illustrates this in action:

Or, they could disappear altogether into the ground until it is safe again, like the night time urinals in London.

Other ways we could encourage individuals to cut their time in a space short is to switch off alternate lights, and/or cut off background music to give people the message to conclude their affairs quickly and leave as it feels like things are closing.

If it is able to be actuated, the building could also enforce a base-level of ventilation by automatically switching on the fans and opening the windows when the safety indicator goes yellow or red. Throwing open the windows when necessary would also also inevitably expose individuals to the elements of nature, encouraging them to disperse and head home, particularly in wintertime.

 

Final Project: Chill buddy

 

 

How to wear it: red pad on right wrist, green on left, yellow on your foot, and an accelerometer attached to your shirt.

When it comes to exercises like pilates and yoga that requires constant attention to breathing and posture, which can be hard for people to follow while exercising.

The other key part of these types of exercises is that the user should have a good balance of the reflection of their state and maintaining the focus on their body. To assist them, they should be able to know how they are breathing and how they are holding up the posture, yet also they should not be interfered from being zen.

Therefore, I came up with a device that assists people with both breathing and posture.

The main problem with designing a device for this was that it has to be light and intimate to the body. If it is too heavy, it is uneasy for the user to focus on inner peace. If the user has to carry/hold on to the device, that would hinder the user from holding up a posture.

Component diagram:

The device consists of three parts: an ECG sensor, a LED neopixel, and an accelerometer. The neopixel lights up in an ideal breathing tempo, and the ECG sensor monitors your heartbeat and your breathing.

The ECG sensor solved the problem of the lightness and closeness to the body. The ECG sensor comes with three attachable pads. They are light and thin, which made it easier for me as a user to focus on myself.

Explanation video: https://drive.google.com/file/d/1ynT0niDqBbBioUs-JuklcV1FvNpeHiIn/view?usp=sharing

Demo video: https://drive.google.com/file/d/18wtBSU3APmGJdT1yotgQdTB6aySNxs1L/view?usp=sharing

default state; inhale according to the tempo of LED neopixel

default state; exhale according to the tempo of LED neopixel

when the heartbeat rises, the light changes to pink and tells you to calm down.

when the back is not straight, the LCD tells you to straighten your back.

Schematics:

Code:

#include <Wire.h>
#include <LiquidCrystal.h>


LiquidCrystal lcd(13, 12, 5, 4, 3, 2);

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h>
#endif

#define PIN 8
#define NUMPIXELS 8

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

int delayval = 500; // delay for half a second
int zpin = A1;

void setup() {
// initialize the serial communication:
Serial.begin(9600);
lcd.begin(16,2);
pixels.begin();pixels.begin();

pinMode(10, INPUT); // Setup for leads off detection LO +
pinMode(11, INPUT); // Setup for leads off detection LO -
pinMode(zpin, INPUT);
}

void loop() {

for(int i=0;i<NUMPIXELS;i++){

// pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
pixels.setPixelColor(i, pixels.Color(0,150,0)); //green

pixels.show(); // This sends the updated pixel color to the hardware.

delay(delayval); // Delay for a period of time (in milliseconds).

lcd.setCursor(0,0);
lcd.print("INHALE ");
lcd.setCursor(0,2);
// lcd.print(" ");

}

for(int k=NUMPIXELS;k>0;k--){


pixels.setPixelColor(k, pixels.Color(0,0,0));

pixels.show();

delay(delayval);

lcd.setCursor(0,0);
lcd.print("EXHALE ");
}

if (analogRead(A0)>700){
for(int i=0;i<NUMPIXELS;i++){


pixels.setPixelColor(i, pixels.Color(235,64,52));

pixels.show();

delay(delayval);


lcd.setCursor(0,2);
lcd.print("CALM DOWN ");

}

for(int k=NUMPIXELS;k>0;k--){


pixels.setPixelColor(k, pixels.Color(235,64,52));

pixels.show();

delay(delayval);


lcd.setCursor(0,2);
lcd.print("CALM DOWN ");

}
}

if(analogRead(zpin)>300){
lcd.setCursor(0,2);
lcd.print("BACK STRAIGHT");
}

if((digitalRead(10) == 1)||(digitalRead(11) == 1)){
Serial.println('!');
}
else{
// send the value of analog input 0:
Serial.println(analogRead(A0));
}
//Wait for a bit to keep serial data from saturating
delay(10);

}