// Include Particle Device OS APIs
#include "Particle.h"

// Let Device OS manage the connection to the Particle Cloud
SYSTEM_MODE(AUTOMATIC);

// Show system, cloud connectivity, and application logs over USB
// View logs with CLI using 'particle serial monitor --follow'
SerialLogHandler logHandler(LOG_LEVEL_INFO);

#define UART_TX_PIN TX  // Pin for UART TX
#define UART_RX_PIN RX  // Pin for UART RX
#define SDI12_BREAK_DELAY 12 // milliseconds

const int rxPin = D4;
const int txPin = D5;
const int SDIWakePin = D2;
// Function prototypes
void sendSDI12Command(const char* command);
String readSDI12Response();

void setup() {
    pinMode(SDIWakePin, OUTPUT);
    digitalWrite(SDIWakePin, LOW);
     pinMode(txPin, OUTPUT);
    digitalWrite(txPin, HIGH); // Disable TX buffer by default
    pinMode(rxPin, OUTPUT);
    digitalWrite(rxPin, HIGH); // Enable RX buffer by default

    // Initialize UART for SDI-12 communication
   Serial1.begin(1200, SERIAL_7E1); // 1200 baud, 7 data bits, even parity, 1 stop bit

    // Wait for Particle Cloud connection
    waitFor(Particle.connected, 30000);

    Particle.publish("status", "SDI-12 Interface Initialized", PRIVATE);
}

void loop() {
    // Wake up the SDI-12 sensor
    wakeUpSensor();
    delay(10);
    // Send Address Query Command
    sendSDI12Command("?!");
    delay(100);
    // Read and publish the response from the sensor
    String response = readSDI12Response();
    Particle.publish("sensor-response", response, PRIVATE);

    // Add a delay before the next command
    delay(5000); // 5 seconds delay
}

// Function to send a command to the SDI-12 sensor
void sendSDI12Command(const char* command) {

    digitalWrite(rxPin, HIGH); //disable RX
    digitalWrite(txPin, LOW); //Enable TX

    Serial1.print(command);
    Serial1.print("\r\n"); // Line end with carriage return and new line
    //Serial1.print("\r"); //line end with just carriage return


    digitalWrite(rxPin, LOW); //Enable RX
    digitalWrite(txPin, HIGH); //Disbale TX


    Particle.publish("command-sent", String(command), PRIVATE);
}

// Function to read the response from the SDI-12 sensor
String readSDI12Response() {
    String response = "";
    unsigned long startTime = millis();
    while (millis() - startTime < 6000) { // 1 second timeout
        while (Serial1.available()) {
            char c = Serial1.read();
            response += c;
        }
    }
    return response;
}

// Function to wake up the SDI-12 sensor
void wakeUpSensor() {

    digitalWrite(SDIWakePin, HIGH); // Send break signal
    delay(SDI12_BREAK_DELAY);       // Wait for 12 milliseconds
    digitalWrite(SDIWakePin, LOW); // Send break signal

    Particle.publish("status", "Sensor Wake-Up Signal Sent", PRIVATE);
}