NodeMCUWiFi http code

NodeMCUWiFiModule.ino

@@ -1,82 +1,97 @@
 #include <ESP8266WiFi.h>  
-#include <WiFiUdp.h>
 #include <spi_flash.h>
+#include <SoftwareSerial.h>
 
-#define WIFI_SSID ""
-#define WIFI_PASS ""
+#define WIFI_SSID "KAIPPUZHAKKUNNEL"
+#define WIFI_PASS "7042754150"
 
-#define IP_BROADCAST "192.168.1.255"
-#define UDP_PORT 8176
+WiFiServer server(80);
 
-String status = "";
-float distance = -1;
-float duration;
-WiFiUDP client;
-
-const int triggerPin = D6;
-const int echoPin = D5;
-
-SPI_DEVICE_TXBIT_LSBFIRST;
+SoftwareSerial sensorSerial; 
+unsigned long int lastPrintTime = 0;
+unsigned long int lastWiFiCheck = 0;
 
+int distance_d = 0;
 
 void setup() {
   delay(5000);
+  WiFi.mode(WIFI_STA);
+  WiFi.setAutoReconnect(true);
   WiFi.begin(WIFI_SSID, WIFI_PASS);
-  pinMode(echoPin, INPUT);
-  pinMode(triggerPin, OUTPUT);
-
-  status = "Connecting";
   while(WiFi.status() != WL_CONNECTED) {
     delay(500);
   }
-  status = WiFi.localIP().toString();
+  String status = WiFi.localIP().toString();
   Serial.begin(9600);
   Serial.println("Got IP: " + status);
-  int err = client.begin(81);
-  if(err == 0) {
-    Serial.println("Failed to create UDP Socket");
-  }
-  else {
-    Serial.println("Created UDP Socket at port 81");
-  }
-  Serial.println(String("IP BROADCAST ID SET TO: ") + String(IP_BROADCAST));
-  Serial.println(String("UDP PORT SET TO: ") + String(UDP_PORT));
+  sensorSerial.begin(9600, SWSERIAL_8N1, D5, D6, false, 64);
+  server.begin();
 }
 
+
 void loop() {
 
-  digitalWrite(triggerPin, LOW);  
-	delayMicroseconds(2);  
-	digitalWrite(triggerPin, HIGH);  
-	delayMicroseconds(10);  
-	digitalWrite(triggerPin, LOW);  
-  duration = pulseIn(echoPin, HIGH);  
-  distance = (duration*.0343)/2;
-
-  if(WiFi.status() != WL_CONNECTED) {
-      WiFi.begin(WIFI_SSID, WIFI_PASS);
-      while(WiFi.status() != WL_CONNECTED) {
-        delay(500);
+  uint8_t data_header = 0xFF;
+  uint8_t data[3]; //comprises of data_high, data_low & checksum.
+  if(sensorSerial.available() >= 4) {
+      if(sensorSerial.read() == 0xFF) {
+        data[0] = sensorSerial.read();
+        data[1] = sensorSerial.read();
+        data[2] = sensorSerial.read();
+        uint8_t checksum = (data_header + data[0] + data[1]) & 0xFF;
+        bool correct_checksum = false;
+        if(data[2] == checksum) {
+          correct_checksum = true;
+          distance_d = (data[0] << 8) | data[1];
+        }
+        else {
+          while(sensorSerial.available()) {
+            sensorSerial.read();
+          }
+        }
+        if(millis() - lastPrintTime >= 3000) {
+            Serial.println("Got Header Byte.");
+            if(correct_checksum)
+              Serial.println("Checksum is correct.");
+            else
+              Serial.println("Checksum is incorrect.");
+            Serial.printf("Current Distance: %d mm\n", distance_d); 
+            lastPrintTime = millis();
+        }
       }
   }
-  String d = String(distance);
-  String d2 = String(duration);
-  Serial.println("Distance is: " + d);
-  Serial.println("Duration is: " + d2);
-  byte *buff = new byte[4];
-  byte *array = (byte *) &distance;
-  for(int i=0;i<4;i++) {
-    buff[i] = array[3-i];
+  if(WiFi.status() != WL_CONNECTED) {
+    if(millis() - lastWiFiCheck >= 10000) {
+      WiFi.reconnect();
+      lastWiFiCheck = millis();
+    }
+    return;
   }
-  Serial.print("Data flipped is: ");
-  for(int i=0;i<4;i++) {
-    Serial.print(buff[i], HEX);
-  }
-  Serial.println("");
+  WiFiClient client = server.available();
+  if (client) {
+    unsigned long clientTimeout = millis();
+    Serial.println("New Client.");
+    while(client.connected() && !client.available()) {
+      if (millis() - clientTimeout > 1000) {
+        Serial.println("Client timeout.");
+        client.stop();
+        return; 
+      }
+      delay(1);
+    }
 
-  client.beginPacket(IP_BROADCAST, UDP_PORT);
-  client.write(buff, sizeof(float));
-  client.endPacket();
-  delay(3000);
-  delete[] buff;
+    if (client.available()) {
+      while (client.available()) {
+        client.read(); 
+      }
+    }
+    
+    client.println("HTTP/1.1 200 OK");
+    client.println("Content-Type: application/json");
+    client.println("Connection: close");
+    client.println();
+    client.printf("{\"distance\": %d, \"unit\": \"mm\"}\n", distance_d);
+    client.stop();
+    Serial.println("Client disconnected.");
+  }
 }