MKR 1010 and A02YYUW Waterproof Ultrasonic Sensor

/*
  My Program

 */

#include <SPI.h>
#include <WiFiNINA.h>
#include <Ultrasonic.h>
#include <Wire.h>

///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = "";        // your network SSID (name)
char pass[] = "";    // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0;                 // your network key index number (needed only for WEP)
int status = WL_IDLE_STATUS;

unsigned char data[4]={};
float distance;
// define ultrasonic ranger data pin
#define RANGERPIN   3
// initialize ultrasonic library
Ultrasonic ultrasonic(RANGERPIN);

WiFiServer server(80);

void setup() {
  //Initialize serial and wait for port to open:
  Serial.begin(19200);
  Serial1.begin(9600);
 // while (!Serial) {
//    ; // wait for serial port to connect. Needed for native USB port only
//  }

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE) {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  String fv = WiFi.firmwareVersion();
  if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
    Serial.println(fv);
    Serial.println(WIFI_FIRMWARE_LATEST_VERSION);
    Serial.println("Please upgrade the firmware");
  }

  // attempt to connect to WiFi network:
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);

    // wait 5 seconds for connection:
    delay(5000);
  }
  server.begin();
  // you're connected now, so print out the status:
  printWifiStatus();

  
}


void loop() {

  char _buffer[7];
  int centimeters;
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("Reconnecting to WiFi...");
    WiFi.disconnect();
    WiFi.begin(ssid, pass);
    delay(5000); 
  }
  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an HTTP request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.write(c);
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the HTTP request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard HTTP response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          client.println("Refresh: 5");  // refresh the page automatically every 5 sec
          client.println();
          client.println("<!DOCTYPE HTML>");
          client.println("<html>");
          //read the pushbutton value into a variable
          //int sensorVal = digitalRead(3);
          //print out the value of the pushbutton
          //client.println(sensorVal);
          // get distance in centimeters
          //centimeters = ultrasonic.MeasureInCentimeters();
          do{
             for(int i=0;i<4;i++)
                {
                   data[i]=Serial1.read();
                   client.println(data[i]);
                }
            }while(Serial1.read()==0xff);
          Serial1.flush();
          if(data[0]==0xff)
            {
              int sum;
              sum=(data[0]+data[1]+data[2])&0x00FF;
              if(sum==data[3])
                {
                  distance=(data[1]<<8)+data[2];
                  if(distance>30)
                    {
                       client.print("distance=");
                       client.print(distance/10);
                       client.println("cm");
                    }else 
                    {
                       client.println("Below the lower limit");
                    }
             }else client.println("ERROR");
     }
         // client.print("Distance is: ");
         // client.print(distance);//0~400cm
         // client.println(" cm");
         // client.println("</html>");
          break;
         
        }
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        } else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(1000);

    // close the connection:
    client.stop();
    Serial.println("client disconnected");
  }
}


void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your board's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm");
}