Ralph Yamamoto
Created March 30, 2021

Optimization of HVAC Performance

Adjust and monitor the performance of home HVAC system to improve energy efficiency.

479
Best Line Powered Proof-of-Concept (PoC): 1st Place
Challenge Climate Change
Optimization of HVAC Performance

Things used in this project

Hardware components

QuickFeather Development Kit
QuickLogic Corp. QuickFeather Development Kit
×1
Adafruit HUZZAH32 – ESP32 Feather Board
Adafruit HUZZAH32 – ESP32 Feather Board
×1
M5StickC PLUS ESP32-PICO Mini IoT Development Kit
M5Stack M5StickC PLUS ESP32-PICO Mini IoT Development Kit
×3
BME280 Temperature Humidity Sensor I2C Breakout
×4
Adafruit - Lithium Ion Polymer Battery - 3.7v 1200mAh
×1
Zulkit Junction Box ABS Plastic Black 3.9 x 2.68 x 1.97 inch
×1
Raspberry Pi 4 Model B
Raspberry Pi 4 Model B
×1

Software apps and online services

SensiML Analytics Toolkit
SensiML Analytics Toolkit
QuickLogic Corp. QuickLogic-Corp/qorc-sdk
Eclipse Mosquitto MQTT Broker
Node-RED
Espressif ESP-IDF
Arduino IDE
Arduino IDE

Hand tools and fabrication machines

ANYCUBIC i3 Mega S FDM 3D Printer

Story

Read more

Schematics

HVAC-Optimizer Schematic

Code

HuzzahESP32_HVAC_MQTT_Client.ino

C/C++
Code to Publish Recognition and BME280 data to MQTT Dashboard and to Subscribe to Reset for QuickFeather (to reset Classification limit)
#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include "arduino_secrets.h"
#include <Wire.h>
#include "Adafruit_Sensor.h"
#include <Adafruit_BME280.h>
#include <ArduinoJson.h>

// LED Pin
const int ledPin = 13;
const int resetPin = 27;

// Set your Static IP address
IPAddress local_IP(10, 0, 0, 205);
// Set your Gateway IP address
IPAddress gateway(10, 0, 0, 1);
IPAddress subnet(255, 255, 255, 0);
IPAddress primaryDNS(8, 8, 8, 8);   //optional
IPAddress secondaryDNS(8, 8, 4, 4); //optional

WiFiClient wifiClient;
PubSubClient client(wifiClient);
long lastMsg = 0;

const byte numChars = 100;
char receivedChars[numChars];   // an array to store the received data
boolean newData = false;
StaticJsonDocument<200> jsonBuffer;

Adafruit_BME280 bme;

float tempBME = 0.0;
float humBME = 0.0;

int recogResult;  // numerical classification

// capture the UART JSON data
void recvWithEndMarker() {
    static byte ndx = 0;
    char endMarker = '\n';
    char rc;
    
    while (Serial1.available() > 0 && newData == false) {
        rc = Serial1.read();

        if (rc != endMarker) {
            receivedChars[ndx] = rc;
            ndx++;
            if (ndx >= numChars) {
                ndx = numChars - 1;
            }
        }
        else {
            receivedChars[ndx] = '\0'; // terminate the string
            ndx = 0;
            newData = true;
        }
    }
}

// parse the JSON to extract the recognition result
void showNewData() {
    if (newData == true) {
//        Serial.print("This just in ... ");
//        Serial.println(receivedChars);
        deserializeJson(jsonBuffer, receivedChars);
        recogResult = jsonBuffer["Classification"];
//        Serial.print("Recognition result: ");
//        Serial.println(recogResult);
        newData = false;
    }
}


void setup_wifi() {
    delay(10);
    // We start by connecting to a WiFi network
    Serial.println();
    Serial.print("Connecting to ");
    Serial.println(ssid);

  if(!WiFi.config(local_IP, gateway, subnet, primaryDNS, secondaryDNS)) {
    Serial.println("Static IP Failed to configure");
  }
    
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
    }
    randomSeed(micros());
    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
//    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("ESP32Client2")) {
//      Serial.println("connected");
      // Subscribe
      client.subscribe("hvac/output");
      client.subscribe("hvac/reset");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}


void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;
  
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    messageTemp += (char)message[i];
  }
  Serial.println();

  // Feel free to add more if statements to control more GPIOs with MQTT

  // If a message is received on the topic hvac/output, you check if the message is either "on" or "off". 
  // Changes the output state according to the message
  if (String(topic) == "hvac/output") {
    Serial.print("Changing output to ");
    if(messageTemp == "on"){
      Serial.println("on");
      digitalWrite(ledPin, HIGH);
    }
    else if(messageTemp == "off"){
      Serial.println("off");
      digitalWrite(ledPin, LOW);
    }
  }

  // If a message is received on the topic hvac/reset, you check if the message is either "true" or "false". 
  // Changes the output state according to the message
  if (String(topic) == "hvac/reset") { 
    if(messageTemp == "true"){
      Serial.print("Resetting QuickFeather");
      digitalWrite(resetPin, LOW);  // assert Reset
      delay(100);      
      digitalWrite(resetPin, HIGH); // release Reset
    }
    else if(messageTemp == "false"){
      Serial.print("Releasing Reset");
      digitalWrite(resetPin, HIGH);
    }
  }
  
}

void setup() {
  Serial.begin(115200);
//  while(!Serial);   // for debug
  Serial.setTimeout(500);// Set time out for 

  Serial1.begin(460800, SERIAL_8N1, 17, 16); // TX, RX swapped
//  while(!Serial1);   // for debug

    if (!bme.begin(0x76)){  
        Serial.println("Could not find a valid BME280 sensor, check wiring!");
//        while (1);
    }
  
  setup_wifi(); // connect to wifi router
  
// configure MQTT and connect
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
  reconnect();

  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);  // LED off

  pinMode(resetPin, OUTPUT);
  digitalWrite(resetPin, HIGH); // not Reset
  
}


void loop() {
    if (!client.connected()) {
      reconnect();
    }
    client.loop();
  
    long now = millis();
    if (now - lastMsg > 30000) {
      lastMsg = now;
    
      tempBME = bme.readTemperature()*1.8 + 32 - 5;
      humBME = bme.readHumidity() + 7;
  
      // Convert the value to a char array
      char tempString[8];
      dtostrf(tempBME, 1, 2, tempString);
      Serial.print("Temperature: ");
      Serial.println(tempString);
      client.publish("hvac/temperature", tempString);
  
      // Convert the value to a char array
      char humString[8];
      dtostrf(humBME, 1, 2, humString);
      Serial.print("Humidity: ");
      Serial.println(humString);
      client.publish("hvac/humidity", humString);

      // Convert the value to a char array
//        char batString[8] = "4.124";  // Replace when resistor divider in place
        char batString[8];
        dtostrf(analogRead(A13)/564.0, 1, 2, batString);  // A13 for HuzzahESP32
        Serial.print("Battery: ");
        Serial.println(batString);
        client.publish("hvac/battery", batString);

        // Publish recognition result
        char recogBuf[8];
        char classBuf[8];
        String recogString;
        String classString;
        switch(recogResult){
          case 0:
            recogString = "Unknown";
            classString = "0";
            break;
          case 1:
            recogString = "Fan";
            classString = "1";
            break;
          case 2:
            recogString = "Furnace";
            classString = "2";
            break;
          case 3:
            recogString = "Off";
            classString = "3";
            break;
          default:
            recogString = "Unknown";
            classString = "0";
            break;
        }
        recogString.toCharArray(recogBuf,8);
        Serial.print("Recognition string: ");
        Serial.println(recogBuf); 
        client.publish("hvac/mode", recogBuf);

        classString.toCharArray(classBuf,8);
        Serial.print("Classification string: ");
        Serial.println(classBuf); 
        client.publish("hvac/classification", classBuf);
      
    }

// Read recognition result from UART
    recvWithEndMarker();
    showNewData();
        
//    delay(1000);
}

M5StickCPlus_BME280_MQTT_Floor2_Static.ino

C/C++
Code for Floor2 Remote Temperature sensor. Other remote sensors are the same with name and address changes.
/**
 * M5StickCPlus_BME280_MQTT.ino
 *
 *  Created on: 02.01.2021
 *  
 * the arduino_secrets.h file:
 * #define SECRET_SSID ""    // network name
 * #define SECRET_PASS ""    // network password
 * #define SECRET_MQTT_USER "public" // broker username
 * #define SECRET_MQTT_PASS "public" // broker password 
 *  
 *
 */

#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include "arduino_secrets.h"
#include <M5StickCPlus.h>
#include <Wire.h>
#include "Adafruit_Sensor.h"
#include <Adafruit_BME280.h>
#include "AXP192.h"

#define USE_SERIAL Serial

// LED Pin
const int ledPin = 10;

// Add your MQTT Broker IP address, example:
//const char* mqtt_server = "192.168.1.144";
const char* mqtt_server = "10.0.0.234";

// Set your Static IP address
IPAddress local_IP(10, 0, 0, 203);
// Set your Gateway IP address
IPAddress gateway(10, 0, 0, 1);

IPAddress subnet(255, 255, 255, 0);
IPAddress primaryDNS(8, 8, 8, 8);   //optional
IPAddress secondaryDNS(8, 8, 4, 4); //optional

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

Adafruit_BME280 bme;

float tempBME = 0.0;
float humBME = 0.0;

void setup() {

    M5.begin();
    Wire.begin(0,26);
    M5.Lcd.setRotation(3);
    M5.Lcd.fillScreen(BLACK);
    M5.Lcd.setCursor(10, 10, 2);
    M5.Lcd.println("TEMPERATURE Floor2");
    pinMode(M5_BUTTON_HOME, INPUT);

    USE_SERIAL.begin(115200);
//    while(!USE_SERIAL);

    USE_SERIAL.println();
    USE_SERIAL.println();
    USE_SERIAL.println();

    
    if (!bme.begin(0x76)){  
        USE_SERIAL.println("Could not find a valid BME280 sensor, check wiring!");
        while (1);
    }    

    setup_wifi();
    client.setServer(mqtt_server, 1883);
    client.setCallback(callback);
  
    pinMode(ledPin, OUTPUT);
    digitalWrite(ledPin, HIGH);
 
}

void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(SECRET_SSID);

  if(!WiFi.config(local_IP, gateway, subnet, primaryDNS, secondaryDNS)) {
    Serial.println("Static IP Failed to configure");
  }

    WiFi.begin(SECRET_SSID, SECRET_PASS);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;
  
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    messageTemp += (char)message[i];
  }
  Serial.println();

  // Feel free to add more if statements to control more GPIOs with MQTT

  // If a message is received on the topic floor2/output, you check if the message is either "on" or "off". 
  // Changes the output state according to the message
  if (String(topic) == "floor2/output") {
    Serial.print("Changing output to ");
    if(messageTemp == "on"){
      Serial.println("on");
      digitalWrite(ledPin, LOW);
    }
    else if(messageTemp == "off"){
      Serial.println("off");
      digitalWrite(ledPin, HIGH);
    }
  }
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("ESP32Client2")) {
      Serial.println("connected");
      // Subscribe
      client.subscribe("floor2/output");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void loop() {
    if (!client.connected()) {
      reconnect();
    }
    client.loop();
  
    long now = millis();
    if (now - lastMsg > 30000) {
      lastMsg = now;
    
      tempBME = bme.readTemperature()*1.8 + 32 - 5;
      humBME = bme.readHumidity() + 7;
      M5.Lcd.setCursor(13, 40, 2);
      M5.Lcd.printf("Temperature: %2.1f F", tempBME);
      M5.Lcd.setCursor(15, 60, 2);
      M5.Lcd.printf("Humidity:    %2.1f %%", humBME);
      M5.Lcd.setCursor(15, 80, 2);
      M5.Lcd.printf("Battery:    %.3f V", M5.Axp.GetBatVoltage());
  
      // Convert the value to a char array
      char tempString[8];
      dtostrf(tempBME, 1, 2, tempString);
      Serial.print("Temperature: ");
      Serial.println(tempString);
      client.publish("floor2/temperature", tempString);
  
      // Convert the value to a char array
      char humString[8];
      dtostrf(humBME, 1, 2, humString);
      Serial.print("Humidity: ");
      Serial.println(humString);
      client.publish("floor2/humidity", humString);

      // Convert the value to a char array
      char batString[8];
      dtostrf(M5.Axp.GetBatVoltage(), 1, 2, batString);
      Serial.print("Battery: ");
      Serial.println(batString);
      client.publish("floor2/battery", batString);
      
    }
        
    delay(1000);
}

Credits

Ralph Yamamoto

Ralph Yamamoto

8 projects • 17 followers

Comments

Awards
Best Line Powered Proof-of-Concept (PoC): 1st Place
Challenge Climate Change