+--------------------------------------------------------------+
|                     ESP32-S3 Sentry Hub                      |
|                                                              |
|  +---------------------+        +-------------------------+  |
|  | Ultrasonic Doppler  |        | 4-20mA Hydrostatic Head |  |
|  | Velocity Transducer |        | Pressure Transmitter    |  |
|  +---------------------+        +-------------------------+  |
|             |                                |               |
|             v                                v               |
|  +--------------------------------------------------------+  |
|  | FreeRTOS Hydraulic Influx Model & FFT Velocity Filter  |  |
|  +--------------------------------------------------------+  |
|             |                                |               |
|             v                                v               |
|  +---------------------+        +-------------------------+  |
|  | 4G LTE-M / NB-IoT   |        | Local RS485 / Modbus    |  |
|  | Cellular Web Relay  |        | Industrial Sluice Gate  |  |
|  +---------------------+        +-------------------------+  |
+--------------------------------------------------------------+

[ESP32-S3 Sentry]                                  [MAX485 Transceiver]
+------------------+                              +--------------------+
|           GPIO18 |<-----------------------------| RO                 |
|           GPIO17 |----------------------------->| DI                 |
|           GPIO16 |----------------------------->| DE & RE (Tied)     |
|                  |                              | A & B (Diff Bus)   |
|                  |                              +--------------------+
|                  |                                        |
|                  |                                        v
|                  |                       [Submersible Doppler Sensor]
|                  |
|           GPIO43 |-----------------------------> [SIM7600 4G Modem RX]
|           GPIO44 |<----------------------------- [SIM7600 4G Modem TX]
|                  |
|             3.3V |-----------------------------> VCC (MAX485)
|             5.0V |-----------------------------> VCC (SIM7600, ESP32)
|              GND |-----------------------------> Common Ground
+------------------+

/*
* Urban Flood Web Real-Time Acoustic & Doppler Drainage Sentry
* Target: ESP32-S3 + Submersible Doppler (RS485) + SIM7600 4G
*/
#include <Arduino.h>
#define RS485_RX_PIN    18
#define RS485_TX_PIN    17
#define RS485_DE_PIN    16
typedef struct {
float velocity_m_s;
float depth_m;
float flow_rate_m3_s;
bool flood_alert;
} FlowTelemetry_t;
static QueueHandle_t xFlowQueue = NULL;
static const float CULVERT_DIAMETER_M = 1.2f;
float compute_discharge(float depth, float velocity) {
if (depth <= 0.0f) return 0.0f;
if (depth > CULVERT_DIAMETER_M) depth = CULVERT_DIAMETER_M;
float theta = 2.0f * acos(1.0f - (2.0f * depth / CULVERT_DIAMETER_M));
float area = (CULVERT_DIAMETER_M * CULVERT_DIAMETER_M / 8.0f) * (theta - sin(theta));
return area * velocity * 0.90f; // Surface-to-mean correction
}
void flow_monitor_task(void *pvParameters) {
while (1) {
// Synthetic Doppler sensor simulation
float vel = 0.8f + (float)(millis() % 150) / 100.0f; // 0.8 - 2.3 m/s
float depth = 0.4f + (float)(millis() % 80) / 100.0f; // 0.4 - 1.2 m
FlowTelemetry_t telem;
telem.velocity_m_s = vel;
telem.depth_m = depth;
telem.flow_rate_m3_s = compute_discharge(depth, vel);
telem.flood_alert = (telem.depth_m > 1.0f);
xQueueSend(xFlowQueue, &telem, 0);
vTaskDelay(pdMS_TO_TICKS(1000));
}
}
void telemetry_relay_task(void *pvParameters) {
FlowTelemetry_t t;
while (1) {
if (xQueueReceive(xFlowQueue, &t, portMAX_DELAY) == pdTRUE) {
Serial.printf("[Drainage Sentry] Velocity: %.2f m/s | Depth: %.2f m | Flow: %.3f m3/s | Alert: %s
",
t.velocity_m_s, t.depth_m, t.flow_rate_m3_s, t.flood_alert ? "CRITICAL FLOOD!" : "NORMAL");
}
}
}
void setup() {
Serial.begin(115200);
xFlowQueue = xQueueCreate(16, sizeof(FlowTelemetry_t));
xTaskCreatePinnedToCore(flow_monitor_task, "FlowMonitor", 3072, NULL, 3, NULL, 1);
xTaskCreatePinnedToCore(telemetry_relay_task, "Telemetry", 4096, NULL, 2, NULL, 0);
Serial.println("Urban Flood Acoustic & Doppler Drainage Sentry Running.");
}
void loop() {
vTaskDelay(pdMS_TO_TICKS(1000));
}