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--- iothings:proiecte:2021:homesecurity [2022/01/27 23:08]
robert.olteanu1909 [Hardware Description]
+++ iothings:proiecte:2021:homesecurity [2022/01/28 01:14] (current)
robert.olteanu1909 [References]
@@ Line 19: / Line 19: @@
   * **LCD 16x2 with I2C Interface** -> A Liquid Crystal Display (LCD), which is a basic module and used commonly in various devices and circuits. 16x2 means it can display 16 characters per line and there are 2 lines. The Inter-Integrated Circuit (I2C) it's a bus interface connection protocol incorporated into devices for serial communication.
-I attached below a diagram generated using [[https://www.circuito.io/|circuito.io]], but I used a version that involved less wires.
+I attached below a diagram generated using [[https://www.circuito.io/|circuito.io]], **but I used a version that involved less wires**.
 {{ :iothings:proiecte:2021:hs_hschematic.png?nolink |}}
@@ Line 34: / Line 34: @@
 | Adafruit_MQTT.h | Arduino library for MQTT support, including accessing the Adafruit.io |
 | Adafruit_MQTT_Client.h | Part of the Adafruit_MQTT library suite |
-====== Workflow ======
-{{ iothings:proiecte:2021:hs_schematic.png }}
+Next thing the software is split in two main parts:
+  - Initial setup - this is where all the components / modules are getting initialized
+    * **WiFi** - The ESP32 tries to connect to the configured network until succeed and it gets the IP address
+    * **MQTT** - The Adafruit.io supports data transfer using MQTT, and on this initial setup there is needed to subscribe to all topics needed while the publishers doesn't need to.
-====== References ======
+<code c>
+#include "Adafruit_MQTT.h"
+#include "Adafruit_MQTT_Client.h"
+Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);
+Adafruit_MQTT_Publish hs_log = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/HS_Log");
+Adafruit_MQTT_Publish hs_door = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/HS_DoorStatus");
+Adafruit_MQTT_Subscribe hs_code = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/HS_DoorCode");
+...
+mqtt.subscribe(&hs_code);
+</code>
+    * **RFC522** - Initialize the SPI Bus then initialize the RFID module.
+    * **LCD16x2** - Initialize the LCD and if the module supports, the backlight for a better display of messages
+    * **Keypad** - Define the keypad and it's GPIO pins used
+<code c>
+#include <Keypad.h>
+#include <SPI.h>
+#include <MFRC522.h>
+#include <LiquidCrystal_I2C.h>
+// Keypad
+#define ROW_NUM     4
+#define COLUMN_NUM  3
+char keys[ROW_NUM][COLUMN_NUM] = {
+  {'#', '0', '*'},
+  {'9', '8', '7'},
+  {'6', '5', '4'},
+  {'3', '2', '1'}
+};
+byte pin_rows[ROW_NUM] = {0, 2, 15, 13};
+byte pin_column[COLUMN_NUM] = {17, 16, 4};
+Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );
+// MFRC522
+#define SS_PIN  5  // ESP32 pin GIOP5
+#define RST_PIN 27 // ESP32 pin GIOP27
+MFRC522 rfid(SS_PIN, RST_PIN);
+// LCD
+int lcdColumns = 16;
+int lcdRows = 2;
+LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);
+...
+SPI.begin(); // init SPI bus
+rfid.PCD_Init(); // init MFRC522
+lcd.init();
+lcd.backlight();
+</code>
+  - Loop - this is looping until the ESP32 is stopped by user.
+    * **Connect to MQTT** - this is done on each iteration to ensure a good connectivity
+    * **Read code subscription** - first time after initial setup the user must insert his/her keycode of 4 characters inside Adafruit.io dashboard
+<code c>
+MQTT_connect();
+Adafruit_MQTT_Subscribe *subscription;
+// Await code to be set from dashboard
+while(code.equals("####")){
+    lcd.clear();
+    lcd.setCursor(0,0);
+    lcd.print("Awaiting code...");
+    while((subscription = mqtt.readSubscription(5000))) {
+        if(subscription == &hs_code) {
+        Serial.print(F("Got: "));
+        Serial.println((char*)hs_code.lastread);
+        code = (char*)hs_code.lastread;
+        }
+    }
+}
+</code>
+    * **Card scan** - Wait until a card is scanned and check if it's a valid one
+<code c>
+if(rfid.PICC_IsNewCardPresent()) {
+Serial.println("Card present");
+if(rfid.PICC_ReadCardSerial()) {
+    Serial.println("Read Serial");
+    for (int i=0; i<rfid.uid.size; i++) {
+    if(rfid.uid.uidByte[i] != availableCard[i]) {
+        char msg[] = "Invalid card scanned";
+        hs_log.publish(msg); // publish message
+        lcd.clear();
+        lcd.setCursor(0,0);
+        lcd.print("Invalid card");
+        delay(3000); // wait to be able to see the message from lcd
+</code>
+    * **Type code** - If the card was valid the user is prompted to input the security code
+<code c>
+bool scannedCard() {
+  int idx = 0;
+  lcd.clear();
+  lcd.setCursor(0,0);
+  lcd.print("Insert code:");
+  lcd.setCursor(0,1);
+  do {
+    do{
+      keyp = keypad.getKey();
+    }while(!keyp);
+    kcode[idx] = keyp;
+    idx++;
+    lcd.print("*");
+  }while(idx < 4);
+  for(int i=0; i<4;i++){
+    if(kcode[i] != code.charAt(i)) { // code is the variable containing the current keycode
+      return false;
+    }
+  }
+  return true;
+}
+</code>
+    * **Update status** - anything from opening a door / disabling alarm etc.
+<code c>
+lcd.clear();
+lcd.setCursor(0,0);
+lcd.print("Door opened");
+char msg[] = "Door opened";
+hs_log.publish(msg); // publish message to logs
+delay(7000); // open door / disable alarm etc.
+lcd.clear();
+lcd.setCursor(0,0);
+lcd.print("Door closed");
+char msg2[] = "Door closed";
+hs_log.publish(msg2); // publish message to logs
+delay(3000); // wait to be able to read the lcd message
+</code>
+====== Software logical workflow ======
+Down below I created a small logical workflow for the code described in the previous chapter to be easily understood.
+{{ iothings:proiecte:2021:hs_schematic.png }}
+====== References ======
+[1] - [[http://esp32.net/]] \\
+[2] - [[https://lastminuteengineers.com/how-rfid-works-rc522-arduino-tutorial/]] \\
+[3] - [[https://esp32io.com/tutorials/esp32-rfid-nfc]] \\
+[4] - [[https://randomnerdtutorials.com/esp32-esp8266-i2c-lcd-arduino-ide/]] \\
+[5] - [[https://esp32io.com/tutorials/esp32-keypad]] \\
+[6] - [[https://io.adafruit.com/api/docs/mqtt.html#adafruit-io-mqtt-api]] \\
+[7] - [[https://raw.githubusercontent.com/AchimPieters/esp32-homekit-camera/master/Images/ESP32-38%20PIN-DEVBOARD.png]] \\