Frequent crashing/losing ability to connect to server cc3200

Hi everyone, I first want to say this isn't a huge priority, but if you have time to look over my code and point out any obvious errors I would appreciate it.

 

The code is based off of the getWeather sketch provided by Energia, it searches a server api that I control for 4 integer values: 3 that are used to program a digital potentiometer and one that controls 3 different GPIO pins which ultimately controls some relays.  The basic idea is the msp430 will test the circuit I select by turning on the correct relay, and the digital potentiometer allows for an user adjustable gain in the circuit being tested.

 

The problem I am having is the cc3200 launchpad frequently becomes unable to connect to server when I run the code below.  The msp430 gets into a state where it keeps trying to connect to server but is never able to.  It typically takes the data from the server about 10 times before becoming unable to connect, and seems to fail more when the data in the server has changed. The code searches the server every 5 seconds.

 

If anyone has any suggestions to potentially help the problem I am having with my code, any feedback would be appreciated.

 

#include <SPI.h>
#include <WiFi.h>

// network login info
char ssid[] = "(my SSID)";
char password[] = "(my Pass)";

IPAddress hostIp(184,106,153,149); //IP address for ThingSpeak
WiFiClient client;

const unsigned long requestInterval = 5000;  // delay between requests (5 sec)
unsigned long lastAttemptTime = 0;           // variable to hold the last time you connected to the server
String currentLine = "";                     // string to hold the text from server
String circuitString = "";                   // string to hold circuit selection
boolean readingCircuit = false;              // if you're currently reading the circuit selection
String invertingString = "";                 // string to hold inverting resistance selection
boolean readingInverting = false;            // if you're currently reading the inverting resistance selection
String nonInvertingString = "";              // string to hold non-inverting resistance selection
boolean readingNonInverting = false;         // if you're currently reading the non-inverting resistance selection
String weightedString = "";                  // string to hold weighted summer resistance selection
boolean readingWeighted = false;             // if you're currently reading the weighted summer resistance selection
int circuit = 1;                             // holds circuit selection (inverting = defalt)
int inverting = 33;                          // holds inverting resistance selection (33 = min value)
int nonInverting = 4;                        // holds non-inverting resistance selection (4 = min value)
int weighted = 17;                           // holds weighted summer resistance selection (17 = min value)
int temp = 0;                                // temporary integer value used in string to int function
boolean flag = false;                        // used to update values (I/O pins and digital pot)

void setup() {
  currentLine.reserve(100);                  // reserve space for strings
  circuitString.reserve(10);
  invertingString.reserve(10);
  nonInvertingString.reserve(10);
  weightedString.reserve(10);
  
  Serial.begin(115200);                      // set baud rate for serial communication
  
  //DIGITAL I/O PINS FOR RELAY CONTROL SETUP
  pinMode (8, OUTPUT);
  pinMode (9, OUTPUT);
  pinMode (10, OUTPUT);
  digitalWrite(8,LOW);
  digitalWrite(9,LOW);
  digitalWrite(10,LOW);
  
  //DIGITAL POTENTIOMETER SETUP
  pinMode (18, OUTPUT);                      // SS pin for SPI data transfer
  SPI.begin();                               // SPI for digital potentiometer programming
  digitalPotWrite(0,inverting);              // initalize digital potentiometer values to base values (gain of ~1.2 V/V, or ~6V output)
  delay(10); //short delay
  digitalPotWrite(2,nonInverting);
  delay(10); //short delay
  digitalPotWrite(1,weighted);
  
  //WIFI CONNECTION SETUP
  Serial.print("Attempting to connect to Network named: ");
  Serial.println(ssid); 
  WiFi.begin(ssid, password);
  while ( WiFi.status() != WL_CONNECTED) {
    Serial.print(".");                       // print dots while we wait to connect
    delay(300);
  }  
  Serial.println("\nYou're connected to the network");
  Serial.println("Waiting for an ip address");  
  while (WiFi.localIP() == INADDR_NONE) {
    Serial.print(".");                       // print dots while we wait for an ip addresss
    delay(300);
  }
  Serial.println("\nIP Address obtained");
  printWifiStatus();
}

void loop() {
    if (client.available()) {
      char inChar = client.read(); // read incoming bytes:
      currentLine += inChar;       // add incoming byte to end of line:    
      if (inChar == '\n') {        // if a newline is found, clear the line:
        currentLine = "";
      } 
      
      // LOOKING FOR CIRCUIT SELECTION
      if ( currentLine.endsWith("<field1>")) {
        readingCircuit = true; // Circuit selection data is beginning, clear circuit string
        circuitString = "";
      }      
      
      // READING CIRCUIT SELECTION DATA
      if (readingCircuit) {
        if (inChar != 'f') { // if you see 'f', you're done reading circuit selection
          circuitString += inChar;
        } 
        else {
          readingCircuit = false; //termination character was found
          Serial.print("-  Circuit Selection: ");
          circuit = getInt(circuitString);
          Serial.print(circuit);
          Serial.println(" (1 = non-inverting, 2 = inverting, 3 = weighted summer)");
        }
      } 
      
      // LOOKING FOR INVERTING RESISTANCE
      if ( currentLine.endsWith("<field2>")) {
        readingInverting = true; // Circuit selection data is beginning, clear inverting string
        invertingString = "";
      }      
      
      // READING INVERTING RESISTANCE DATA
      if (readingInverting) {
        if (inChar != 'f') { // if you see 'f', you're done reading inverting selection
          invertingString += inChar;
        } 
        else {
          readingInverting = false; //termination character was found
          Serial.print("-  Inverting Resistance Selection: ");
          inverting = getInt(invertingString);
          Serial.println(inverting);
        }
      }  
      
      // LOOKING FOR NON-INVERTING RESISTANCE
      if ( currentLine.endsWith("<field3>")) {
        readingNonInverting = true; // Circuit selection data is beginning, clear non-inverting string
        nonInvertingString = "";
      }      
      
      // READING NON-INVERTING RESISTANCE DATA
      if (readingNonInverting) {
        if (inChar != 'f') { // if you see 'f', you're done reading non-inverting selection
          nonInvertingString += inChar;
        } 
        else {
          readingNonInverting = false; //termination character was found
          Serial.print("-  Non-Inverting Resistance Selection: ");
          nonInverting = getInt(nonInvertingString);
          Serial.println(nonInverting);
        }
      }
    
      // LOOKING FOR WEIGHTED SUMMER RESISTANCE
      if ( currentLine.endsWith("<field4>")) {
        readingWeighted = true; // Circuit selection data is beginning, clear weighted summer string
        weightedString = "";
      }      
      
      // READING WEIGHTED SUMMER RESISTANCE DATA
      if (readingWeighted) {
        if (inChar != 'f') { // if you see 'f', you're done reading weighted summer selection
          weightedString += inChar;
        } 
        else {
          readingWeighted = false; //termination character was found
          Serial.print("-  Weighted Summer Resistance Selection: ");
          weighted = getInt(weightedString);
          Serial.println(weighted);
          flag = true; // Done reading data, so set flag
        }
      }
      if (flag) {  //done reading server data, now update digital potentiometer and GPIO pins
        Serial.println("Done reading values!");
        digitalPotWrite(0,nonInverting); //write to resistor 1
        digitalPotWrite(1,weighted); //write to resistor 2
        digitalPotWrite(2,inverting); //write to resistor 3
        if (circuit == 2) { // Non-Inverting selected
          Serial.println("Non-Inverting resistance updated!");
          digitalWrite(8,HIGH);
          digitalWrite(9,LOW);
          digitalWrite(10,LOW);
        }
        else if (circuit == 1) { // Inverting selected
          Serial.println("Inverting resistance updated!");
          digitalWrite(8,LOW);
          digitalWrite(9,HIGH);
          digitalWrite(10,LOW);
        }
        else { // Weighted summer selected, default case
          Serial.println("Weighted summer resistance updated!");
          digitalWrite(8,LOW);
          digitalWrite(9,LOW);
          digitalWrite(10,HIGH);
        }       
        Serial.println("");
        flag = false; //reset flag
      }
  }
  else if (millis() - lastAttemptTime > requestInterval) {
    connectToServer();
  }
}

void connectToServer(){
  Serial.println("connecting to server...");
  if (client.connect(hostIp, 80)) {
    Serial.println("Connected! Reading web server data...");
    client.println("GET /channels/(my channel id)/feed/last.xml"); // make HTTP GET request to ThingSpeak
    client.print("HOST: http://api.thingspeak.com\n");   // declare correct server
    client.println("Connection: close");                 // close connection
    client.println();
  }
  lastAttemptTime = millis(); // timestamp for this connection
}

void printWifiStatus() {
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID()); //print SSID
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip); //print IP address
  Serial.println("");
}

int digitalPotWrite(int address, int value) {
  Serial.println("Writing resistance values");
  digitalWrite(18,LOW);    // take the SS pin low to select the digital pot
  SPI.transfer(address);   // send in the address (resistor selection)
  SPI.transfer(value);     // send in the value (resistor value)
  digitalWrite(18,HIGH);   // take the SS pin high to de-select the digital pot
}

int getInt(String input){  //converts string to integer
  int i = 1;  
  while(input[i] != '<'){
    i++;
  }
  input = input.substring(1,i);
  char carray[20];
  input.toCharArray(carray, sizeof(carray));
  temp = atoi(carray); //atoi() converts an array of char to a string
  return temp;
}