Passive or display water module (No wireless communication)

04/20/2026-Owned and Upkept by Sufyan-Taha
ESP-32 DEVELOPMENT BOARD/ESP-IDF

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "driver/gpio.h"
#include "esp_adc/adc_oneshot.h"
#include "esp_log.h"

static const char *TAG = "WaterMonitor";

// --- Configuration Defines ---
#define FLOW_SENSOR_GPIO        GPIO_NUM_4
#define ESP_INTR_FLAG_DEFAULT   0

// ADC Channels for Unit 1 (GPIO 34 and 35)
#define TDS_ADC_CHANNEL         ADC_CHANNEL_6  // GPIO 34
#define NITRO_ADC_CHANNEL       ADC_CHANNEL_7  // GPIO 35

// Calibration constants (Examples: Adjust based on your sensor datasheets)
#define FLOW_CALIBRATION_FACTOR 7.5   // Pulses per second per liter/min
#define ADC_VREF_MV             3300  // ESP32 VCC voltage in mV
#define ADC_MAX_RESOLUTION      4095  // 12-bit ADC

// --- Global Variables ---
volatile uint32_t pulse_count = 0;
static adc_oneshot_unit_handle_t adc1_handle;

// --- Interrupt Service Routine (ISR) for Flow Sensor ---
static void IRAM_ATTR flow_sensor_isr_handler(void* arg) {
    pulse_count++;
}

// --- Initialization Functions ---

static void init_flow_sensor(void) {
    gpio_config_t io_conf = {
        .intr_type = GPIO_INTR_POSEDGE, // Trigger on rising edge
        .mode = GPIO_MODE_INPUT,
        .pin_bit_mask = (1ULL << FLOW_SENSOR_GPIO),
        .pull_down_en = GPIO_PULLDOWN_DISABLE,
        .pull_up_en = GPIO_PULLUP_ENABLE // Use internal pull-up if sensor is open-drain
    };
    gpio_config(&io_conf);

    // Install ISR service and add handler
    gpio_install_isr_service(ESP_INTR_FLAG_DEFAULT);
    gpio_ Wheeler_isr_handler(FLOW_SENSOR_GPIO, flow_sensor_isr_handler, NULL);
    ESP_LOGI(TAG, "Flow sensor ISR initialized on GPIO %d", FLOW_SENSOR_GPIO);
}

static void init_adc_sensors(void) {
    // Configure ADC Unit 1
    adc_oneshot_unit_init_config_t init_config1 = {
        .unit_id = ADC_UNIT_1,
        .clk_src = ADC_DIGI_CLK_SRC_DEFAULT,
    };
    ESP_ERROR_CHECK(adc_oneshot_new_unit(&init_config1, &adc1_handle));

    // Configure ADC Channels with 12-bit bitwidth and 12dB attenuation (0 - 3.3V range)
    adc_oneshot_chan_config_t config = {
        .bitwidth = ADC_BITWIDTH_12,
        .atten = ADC_ATTEN_DB_12,
    };
    
    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc1_handle, TDS_ADC_CHANNEL, &config));
    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc1_handle, NITRO_ADC_CHANNEL, &config));
    
    ESP_LOGI(TAG, "ADC channels initialized successfully.");
}

// --- Processing Functions ---

float read_voltage_mv(adc_channel_t channel) {
    int raw_adc_value = 0;
    // Read raw data from ADC
    ESP_ERROR_CHECK(adc_oneshot_read(adc1_handle, channel, &raw_adc_value));
    // Convert to millivolts
    return ((float)raw_adc_value * ADC_VREF_MV) / ADC_MAX_RESOLUTION;
}

// --- Main Telemetry Task ---
void water_monitor_task(void *pvParameters) {
    uint32_t last_pulse_count = 0;
    float total_liters = 0.0;

    while (1) {
        // 1. Calculate Flow Rate (Sampled every 2 seconds)
        vTaskDelay(pdMS_TO_TICKS(2000));
        
        uint32_t current_pulses = pulse_count;
        uint32_t pulses_in_period = current_pulses - last_pulse_count;
        last_pulse_count = current_pulses;

        // Flow rate in Liters/Minute = (Pulses / 2 seconds) / Calibration Factor * 60 seconds
        float flow_rate_lpm = ((float)pulses_in_period / 2.0) / FLOW_CALIBRATION_FACTOR;
        // Total volume = accumulated liters over the 2-second step
        total_liters += (flow_rate_lpm / 60.0) * 2.0;

        // 2. Read Chemical Sensors (Voltages)
        float tds_voltage = read_voltage_mv(TDS_ADC_CHANNEL);
        float nitro_voltage = read_voltage_mv(NITRO_ADC_CHANNEL);

        // 3. Convert Voltages to meaningful Environmental metrics
        // Note: These formulas scale linearly. Check your specific sensor calibration curves!
        float tds_ppm = (tds_voltage / 1000.0) * 500.0;         // Dummy conversion for TDS
        float ammonia_mgL = (nitro_voltage / 1000.0) * 10.0;    // Dummy conversion for Ammonia

        // 4. Log Outputs
        ESP_LOGI(TAG, "===============================================");
        ESP_LOGI(TAG, "Water Flow Rate:   %.2f L/min", flow_rate_lpm);
        ESP_LOGI(TAG, "Total Water Used:  %.2f Liters", total_liters);
        ESP_LOGI(TAG, "Heavy Metals/TDS:  %.1f ppm (Raw: %.0fmV)", tds_ppm, tds_voltage);
        ESP_LOGI(TAG, "Ammonia/Nitrogen:  %.2f mg/L (Raw: %.0fmV)", ammonia_mgL, nitro_voltage);
    }
}

void app_main(void) {
    ESP_LOGI(TAG, "Starting Water Quality & Usage Monitoring System...");

    // Initialize Peripherals
    init_flow_sensor();
    init_adc_sensors();

    // Create execution task
    xTaskCreate(water_monitor_task, "water_monitor_task", 4096, NULL, 5, NULL);
}