Water Level Monitoring and Flood Alert System

// Project : Water Level Monitoring and Flood Alert System
// Board: RAK3372 (STM32WL5)
// Base: RAK1907
// Sensors: RAK12005 Rain Sensor, RAK12030 BME680 Environment Sensor, RAK12032 DS18B20 Temperature Sensor
// Display: RAK1821 OLED (Optional)
// LoRaWAN Platform: The Things Stack
 
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME680.h> // For BME680
#include <OneWire.h>         // For DS18B20
#include <DallasTemperature.h> // For DS18B20
#include <LoRaWan-RAK3372.h> // LoRaWAN library for RAK3372
#include <SPI.h>
 
// LoRaWAN Configuration (OTAA) - REPLACE WITH YOUR THE THINGS STACK CREDENTIALS!
uint8_t nodeDeviceEUI[8] = {0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX};
uint8_t nodeAppEUI[8] = {0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX};
uint8_t nodeAppKey[16] = {0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX};
 
// LoRaWAN Region Configuration
LoRaMacRegion_t loraWanRegion = LORAMAC_REGION_EU868;
 
// Sensor Pins
#define RAIN_SENSOR_PIN WB_A0 // Analog pin for rain sensor
#define ONE_WIRE_BUS WB_IO2 // Pin for DS18B20 sensor (ambient/water temperature)
 
// Sensor Instances
Adafruit_BME680 bme; // I2C
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
 
// Variables to store readings
bool is_raining;
float air_temperature, air_humidity, air_pressure;
float external_temperature; // DS18B20 Temperature
 
void setup() {
  Serial.begin(115200);
  delay(100);
  Serial.println("Starting IoT Flood Monitoring...");
 
  Wire.begin();
 
  // Initialize BME680
  if (!bme.begin()) {
    Serial.println("Could not find a valid BME680 sensor, check wiring!");
    while (1);
  }
  bme.setTemperatureOversampling(BME680_OVERSAMPLING_8X);
  bme.setHumidityOversampling(BME680_OVERSAMPLING_4X);
  bme.setPressureOversampling(BME680_OVERSAMPLING_4X);
  bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
  bme.setGasHeater(320, 150);
 
  // Initialize DS18B20
  sensors.begin();
 
  // Initialize rain sensor
  pinMode(RAIN_SENSOR_PIN, INPUT);
 
  // Initialize LoRaWAN
  if (api.lorawan.setRegion(loraWanRegion)) {
    Serial.printf("LoRaWAN region configured to %d\n", loraWanRegion);
  } else {
    Serial.println("Failed to configure LoRaWAN region.");
    while (1);
  }
 
  if (api.lorawan.setAppKey(nodeAppKey) &&
     api.lorawan.setAppEUI(nodeAppEUI) &&
     api.lorawan.setDevEUI(nodeDeviceEUI)) {
    Serial.println("LoRaWAN credentials configured.");
  } else {
    Serial.println("Failed to configure LoRaWAN credentials.");
    while (1);
  }
 
  Serial.println("Attempting to join LoRaWAN network (OTAA)...");
  if (api.lorawan.join()) {
    Serial.println("Joined LoRaWAN network!");
  } else {
    Serial.println("Failed to join LoRaWAN network. Retrying...");
    while(1);
  }
  delay(2000);
}
 
void loop() {
  readSensors();
  sendLoRaWANData();
 
  // Flood alert logic (simple example)
  if (is_raining && air_pressure < 980.0) { // Rain and low pressure
    Serial.println("POSSIBLE FLOOD ALERT!");
    // A specific, higher priority alert packet could be sent here
  }
 
  Serial.println("Entering low power mode...");
  api.system.sleep.all(120000); // Sleep for 2 minutes (120000 ms)
}
 
void readSensors() {
  // Read rain sensor
  int rain_analog_val = analogRead(RAIN_SENSOR_PIN);
  is_raining = (rain_analog_val < 500); // Simple threshold: if value is low, it's raining
  Serial.printf("Rain Sensor: %d (Raining: %s)\n", rain_analog_val, is_raining? "Yes" : "No");
 
  // Read BME680
  if (!bme.performReading()) {
    Serial.println("Failed to perform BME680 reading.");
  } else {
    air_temperature = bme.temperature;
    air_humidity = bme.humidity;
    air_pressure = bme.pressure / 100.0; // hPa
    Serial.printf("Air Temp: %.2f C, Air Hum: %.2f %%, Air Pres: %.2f hPa\n", air_temperature, air_humidity, air_pressure);
  }
 
  // Read DS18B20
  sensors.requestTemperatures();
  external_temperature = sensors.getTempCByIndex(0);
  if (external_temperature == DEVICE_DISCONNECTED_C) {
    Serial.println("Failed to read DS18B20.");
  } else {
    Serial.printf("External Temp: %.2f C\n", external_temperature);
  }
}
 
void sendLoRaWANData() {
  // Payload format:
  // Byte 0: Rain (0 or 1)
  // Byte 1-2: Air temperature (x100)
  // Byte 3-4: Air humidity (x100)
  // Byte 5-6: Air pressure (x10)
  // Byte 7-8: External temperature (x100)
 
  uint8_t payload[9]; // Adjusted payload size
  int16_t air_temp_int = (int16_t)(air_temperature * 100);
  uint16_t air_hum_int = (uint16_t)(air_humidity * 100);
  uint16_t air_pres_int = (uint16_t)(air_pressure * 10);
  int16_t ext_temp_int = (int16_t)(external_temperature * 100);
 
  payload[0] = is_raining? 1 : 0;
  payload[1] = (air_temp_int >> 8) & 0xFF;
  payload[2] = air_temp_int & 0xFF;
  payload[3] = (air_hum_int >> 8) & 0xFF;
  payload[4] = air_hum_int & 0xFF;
  payload[5] = (air_pres_int >> 8) & 0xFF;
  payload[6] = air_pres_int & 0xFF;
  payload[7] = (ext_temp_int >> 8) & 0xFF;
  payload[8] = ext_temp_int & 0xFF;
 
  Serial.print("Sending LoRaWAN packet: ");
  for (int i = 0; i < sizeof(payload); i++) {
    Serial.printf("%02X ", payload[i]);
  }
  Serial.println();
 
  if (api.lorawan.send(sizeof(payload), payload, 1, true)) {
    Serial.println("LoRaWAN packet sent successfully.");
  } else {
    Serial.println("Failed to send LoRaWAN packet.");
  }
}
 
// Example Payload Formatter (Decoder) for The Things Stack (Custom Javascript)
/*
function decodeUplink(input) {
  var data = {};
  var bytes = input.bytes;
 
  // Decode Rain (1 byte, boolean)
  data.is_raining = (bytes[0] === 1);
 
  // Decode air temperature (2 bytes, int16, x100)
  data.air_temperature = ((bytes[1] << 8 | bytes[2]) / 100.0);
 
  // Decode air humidity (2 bytes, uint16, x100)
  data.air_humidity = ((bytes[3] << 8 | bytes[4]) / 100.0);
 
  // Decode air pressure (2 bytes, uint16, x10)
  data.air_pressure = ((bytes[5] << 8 | bytes[6]) / 10.0);
 
  // Decode external temperature (2 bytes, int16, x100)
  data.external_temperature = ((bytes[7] << 8 | bytes[8]) / 100.0);
 
  return {
    data: data,
    warnings: [],
    errors: []
  };
}
*/