traffic_client.ino

/*  Connects to the home WiFi network
 *  Asks some network parameters
 *  Sends and receives message from the server in every 2 seconds
 *  Communicates: wifi_server_01.ino
 */ 
#include <SPI.h>
#include <ESP8266WiFi.h>

byte ledPin = 2;
char ssid[] = "Hackspace_2_4";           // SSID of your home WiFi
char pass[] = "xxxx_x_xxx";            // password of your home WiFi
int sensorTA12 = A0; //  Pin read in
int sensorValue = 0;
float nVPP;   // Voltage measured across resistor
float nCurrThruResistorPP; // Peak Current Measured Through Resistor
float nCurrThruResistorRMS; // RMS current through Resistor
float nCurrentThruWire;     // Actual RMS current in Wire
#define USE_SERIAL Serial

unsigned long askTimer = 0;

IPAddress server(192,168,0,80);       // the fix IP address of the server
WiFiClient client;


void setup() {
  pinMode(sensorTA12, INPUT);
WiFi.disconnect();
  Serial.begin(115200);               // only for debug
  for (uint8_t t = 4; t > 0; t--)
  {
    USE_SERIAL.printf("[SETUP] WAIT %d...\n", t);
    USE_SERIAL.flush();
    delay( 1000 );
  }
  WiFi.begin(ssid, pass);             // connects to the WiFi router
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println("Connected to wifi");
  Serial.print("Status: "); Serial.println(WiFi.status());    // Network parameters
  Serial.print("IP: ");     Serial.println(WiFi.localIP());
  Serial.print("Subnet: "); Serial.println(WiFi.subnetMask());
  Serial.print("Gateway: "); Serial.println(WiFi.gatewayIP());
  Serial.print("SSID: "); Serial.println(WiFi.SSID());
  Serial.print("Signal: "); Serial.println(WiFi.RSSI());
  pinMode(ledPin, OUTPUT);
}

void loop () {

  sensorValue = analogRead(sensorTA12);
  Serial.println(sensorValue);
  client.connect(server, 80);   // Connection to the server
  digitalWrite(ledPin, LOW);    // to show the communication only (inverted logic)
  Serial.println(".");
  nVPP = getVPP();
  nVPP = nVPP * 100;
  client.println(nVPP,3);
  client.println("\r");  // sends the message to the server
  String answer = client.readStringUntil('\r');   // receives the answer from the sever
  Serial.println("from server: " + answer);
  client.flush();
  digitalWrite(ledPin, HIGH);
  delay(2000);                  // client will trigger the communication after two seconds
  //nVPP = getVPP();
   
   /*
   Use Ohms law to calculate current across resistor
   and express in mA 
   */
   
   nCurrThruResistorPP = (nVPP/200.0) * 1000.0;
   
   /* 
   Use Formula for SINE wave to convert
   to RMS 
   */
   
   nCurrThruResistorRMS = nCurrThruResistorPP * 0.707;
   
   /* 
   Current Transformer Ratio is 1000:1...
   
   Therefore current through 200 ohm resistor
   is multiplied by 1000 to get input current
   */
   
   nCurrentThruWire = nCurrThruResistorRMS * 1000;

   
   Serial.print("Volts Peak : ");
   Serial.println(nVPP,3);
 
   
   Serial.print("Current Through Resistor (Peak) : ");
   Serial.print(nCurrThruResistorPP,3);
   Serial.println(" mA Peak to Peak");
   
   Serial.print("Current Through Resistor (RMS) : ");
   Serial.print(nCurrThruResistorRMS,3);
   Serial.println(" mA RMS");
   
   Serial.print("Current Through Wire : ");
   Serial.print(nCurrentThruWire,3);
   Serial.println(" mA RMS");
   
   Serial.println();
}

float getVPP()
{
  float result;
  int readValue;             //value read from the sensor
  int maxValue = 0;          // store max value here
   uint32_t start_time = millis();
   while((millis()-start_time) < 1000) //sample for 1 Sec
   {
       readValue = analogRead(sensorTA12);
       // see if you have a new maxValue
       if (readValue > maxValue) 
       {
           /*record the maximum sensor value*/
           maxValue = readValue;
       }
   }
   
   // Convert the digital data to a voltage
   result = (maxValue * 5.0)/1024.0;
  
   return result;
 }