user904: I have my Arduino code as below.I am trying to send Serial request and get response for it. I can able to send request mentioned in Setup function and also able to switch cases. Problem i am facing Print character buffer after storing the  values. can someone suggest me how to store integer value into charcter buffer and print result later.
#include "glob.h"
const int BUFFER_SZ = 32;
char sendBuffer[60]={'0'};

void Take_Reading() {

  for (int row = 0; row < 8; row++)
  {
    //   // get rid of me:
    digitalWrite(SO_enable, array[row][0]);
    digitalWrite(S1_enable, array[row][1]);
    digitalWrite(S2_enable, array[row][2]);
    delay(50);
    analog_1_pv[row] = ANALOG_SCALING * analogRead(A0);
    analog_2_pv[row] = ANALOG_SCALING * analogRead(A1);
    analog_3_pv[row] = ANALOG_SCALING * analogRead(A2);
    if ( (analog_1_pv[row] <= MINV_RANGE || (analog_1_pv[row] >= MAXV_RANGE) ))
    {
      Current_Value1[row] =  0.0;
    }
    else
    {
      Current_Value1[row] =  (analog_1_pv[row] * 12.5) - 31.25;

    }

    if (  (analog_2_pv[row] <= MINV_RANGE || (analog_2_pv[row] >= MAXV_RANGE) ))
    {
      Current_Value2[row] =  0.0;
    }
    else
    {
      Current_Value2[row] =  (analog_2_pv[row] * 12.5) - 31.25;

    }

    if (  (analog_3_pv[row] <= MINV_RANGE || (analog_3_pv[row] >= MAXV_RANGE) ))
    {
      Current_Value3[row] =  0.0;
    }
    else
    {
      Current_Value3[row] =  (analog_3_pv[row] * 12.5) - 31.25;

    }


    Mod_current[row] = (uint16_t)(Mul_Factor * Current_Value1[row]);
    Mod_current[row + 8] = (uint16_t)(Mul_Factor * Current_Value2[row]);
    Mod_current[row + 16] = (uint16_t)(Mul_Factor * Current_Value3[row]);


  }

}









int ID_Check() {

  int ID_value;
  for (int row = 0; row < 8; row++)
  {
    digitalWrite(SO_enable, array[row][0]);
    digitalWrite(S1_enable, array[row][1]);
    digitalWrite(S2_enable, array[row][2]);
    Status_Out[row] = digitalRead(Output_Read);

  }

  ID_value = 1 * Status_Out[7] + 2 * Status_Out[6] + 4 * Status_Out[5] + 8 * Status_Out[4] + 16 * Status_Out[3] + 32 * Status_Out[2] + 64 * Status_Out[1] + 128 * Status_Out[0];
  return (ID_value);

}




int  Take_Temp_Reading()
{

  Temp_Total = Temp_Total - Temp_readings[Temp_index];
  Temp_readings[Temp_index] = analogRead(A5);
  Temp_Total = Temp_Total + Temp_readings[Temp_index];
  Temp_index = Temp_index + 1;

  if (Temp_index >= numReadings)
  {
    Temp_index = 0;
    Temp_Average = Temp_Total / numReadings;
  }
  temp = (Temp_Average * 5.0) / 1023.0;


  //  temp = float(analogRead(A5)) * 5.0 / 1024.0;
  temp_int = (int)(temp * 100.0);
  return (temp_int);
  // Serial.print("Temp"); Serial.println(temp);
}

int SPD_Check()
{

  SPD_STATUS = digitalRead(SPD_STATUS_PIN);
  return (SPD_STATUS);
}

int  DC_Status()
{

  DC_STATUS = digitalRead(DC_STATUS_PIN);
  return (DC_STATUS);

}



int   Take_HV_Reading()
{

  //int analog_int= analogRead(A4);

  total = total - readings[index];
  // read from the sensor:
  readings[index] = analogRead(A4);
  // add the reading to the total:
  total = total + readings[index];
  // advance to the next position in the array:
  index = index + 1;

  // if we're at the end of the array...
  if (index >= numReadings1)
  {
    index = 0;
    average = total / numReadings1;

  }
  else
  {

    HV_voltage = (average * 5.0) / 1023.0;
  }
  if (HV_voltage <= 0.25)
  {

    Conv_HV_voltage = 0.0;
  }
  else
  {
    Conv_HV_voltage = 197.837837838 * HV_voltage + 10.8108108108;
  }

  HV_Reading = (uint16_t)(Conv_HV_voltage * 10);

  //  HV_Reading = (uint16_t)(Conv_HV_voltage * 10);

  return(HV_Reading);
}


void  Serial_Command1()

{
   Take_Reading();
  int Temp_read=Take_Temp_Reading();
  int HV_Read=Take_HV_Reading();
  SPD=SPD_Check();
  DISCONNECTOR=DC_Status();
  Serial.println("Command1 executed ");


  sendBuffer[1]=char(Mod_current[1]) ;
  sendBuffer[2]= ',';
  sendBuffer[2]= Mod_current[1];
  sendBuffer[3]= ',';

  sendBuffer[4]= Mod_current[2];
  sendBuffer[5]= ',';
  sendBuffer[6]= Mod_current[3];
  sendBuffer[7]= ',';

  sendBuffer[8]= Mod_current[4];
  sendBuffer[9]= ',';
  sendBuffer[10]= Mod_current[5];
  sendBuffer[11]= ',';

  sendBuffer[12]= Mod_current[6];
  sendBuffer[13]= ',';
  sendBuffer[14]= Mod_current[7];
  sendBuffer[15]= ',';

  sendBuffer[16]= Mod_current[8];
  sendBuffer[17]= ',';
  sendBuffer[18]= Mod_current[9];
  sendBuffer[19]= ',';

  sendBuffer[20]= Mod_current[10];
  sendBuffer[21]= ',';
  sendBuffer[22]= Mod_current[11];
  sendBuffer[23]= ',';


  sendBuffer[24]= Mod_current[12];
  sendBuffer[25]= ',';
  sendBuffer[26]= Mod_current[13];
  sendBuffer[27]= ',';

  sendBuffer[28]= Mod_current[23];
  sendBuffer[29]= ',';
  sendBuffer[30]= Mod_current[22];
  sendBuffer[31]= ',';

  sendBuffer[32]= Mod_current[21];
  sendBuffer[33]= ',';
  sendBuffer[34]= Mod_current[20];
  sendBuffer[35]= ',';

  sendBuffer[36]= Mod_current[19];
  sendBuffer[37]= ',';
  sendBuffer[38]= Mod_current[18];
  sendBuffer[39]= ',';

  sendBuffer[40]= Mod_current[17];
  sendBuffer[41]= ',';
  sendBuffer[42]= Mod_current[16];
  sendBuffer[43]= ',';

  sendBuffer[44]= Mod_current[15];
  sendBuffer[45]= ',';
  sendBuffer[46]= Mod_current[14];
  sendBuffer[47]= ',';
  sendBuffer[48]= Temp_read;
  sendBuffer[49]= ',';
  sendBuffer[50]= HV_Read;
  sendBuffer[51]= ',';
  sendBuffer[52]= SPD;
  sendBuffer[53]= ',';
  sendBuffer[54]= DISCONNECTOR;

  Serial.println(sendBuffer[1]);

}

void Serial_Command2(int a)
{

  Serial.print("Command2 executed: ");
  Serial.println(a);
}





void setup()
{
  Serial.begin(57600);
  Serial.println("Format 1: <SMCB1,1>");
  Serial.println("Format 2: <SMCB1,1,Length>");

}

// Parse the request, WITHOUT the '<' and '>' delimiters.
void parseRequest(char *request)
{
  // Check the request starts with the prefix "SMCB1,1".
  if (strncmp(request, "SMCB1,1", 7) != 0) {
    Serial.println(F("Error: bad request prefix"));
    return;
  }

  // Remove that known prefix.
  // Now we have either "", ",Length" or ",Timer,On_OFF"
  request += 7;

  // Format 1: ""
  if (request[0] == '\0') {
    //Serial.println(F("Received format 1"));
    Serial_Command1();
    return;
  }

  // Remove the leading comma.
  // Now we have either "Length" or "Timer,On_OFF"
  if (request[0] != ',') {
    Serial.println(F("Error: ',' expected"));
    return;
  }
  request++;

  // Format 2: "Length", no comma.
  char * comma = strchr(request, ',');
  if (!comma) {

    int length = atoi(request);
    Serial_Command2(length);
    //Serial.print(F("Received format 2, length = "));
    // Serial.println(length);
    return;
  }


}

void loop()
{
  static char buffer[BUFFER_SZ];  // received chars
  static size_t pos;              // current position in buffer
  static bool insideRequest;      // are we between '<' and '>'?

  if (Serial.available()) {
    char c = Serial.read();
    if (insideRequest) {
      if (c == '>') {  // end of request received
        buffer[pos] = '\0';  // terminate the string
        parseRequest(buffer);
        pos = 0;             // get ready for the next request
        insideRequest = false;
      }
      else if (pos < BUFFER_SZ-1) {  // add char to buffer
        buffer[pos++] = c;
      }
    }
    else if (c == '<') {  // start of request
      insideRequest = true;
    }
  }
}

Golb.h header file contains
#ifndef GLOB_H
#define GLOB_H
int counter=0;
int Mod_current[24];
const int numReadings = 10;
const int numReadings1 = 10;
int Temp_Total = 0;
int Temp_readings[numReadings];
int Temp_index = 0;
int Temp_Average = 0;
float  reading[10];
float Total = 0.0;
static int i;

int readings[numReadings];
int index = 0;
int total = 0;
int average = 0;

// These PinS are use to enable and disable analog MUX
int SO_enable = 5;
int S1_enable = 4;
int S2_enable = 3;

// temprature sensor permeter
int TempPin = 5;
float temp;
static int temp_int;

// digital mux setting
int Output_Read = 2;

float Vref = 2.5;
// Used for sensor conversion
float ANALOG_SCALING = 0.004887585532746823;
//tempfloat ANALOG_SCALING=0.0049560117;


int Sensor_Value0 = 0;
int Sensor_Value1 = 0;
int Sensor_Value2 = 0;
float analog_1_pv[8];
float analog_2_pv[8];
float analog_3_pv[8];
int Status_Out[8];

//SPD & DC STATUS PIN
static int SPD_STATUS_PIN = 6;
static int DC_STATUS_PIN = 7;

int row;

int Mul_Factor = 10;

float Current_Value1[8] = {
  0.0
};
float Current_Value2[8] = {
  0.0
};
float Current_Value3[8] = {
  0.0
};

//HV perameter setting are defined here
int HV_SensorValue;
int HV_Reading;
float HV_voltage;
float Conv_HV_voltage;
unsigned  int DC_STATUS = 0;
unsigned int SPD_STATUS = 0;
float MINV_RANGE = 2.52;
//float MIDV_RANGE1=1.875;
float MAXV_RANGE = 4.5;

int SPD;
int DISCONNECTOR;


int Serial_Status=0;




int array[8][3] = {
  {
    0, 0, 0
  }
  , {
    0, 0, 1
  }
  , {
    0, 1, 0
  }
  , {
    0, 1, 1
  }
  , {
    1, 0, 0
  }
  , {
    1, 0, 1
  }
  , {
    1, 1, 0
  }
  , {
    1, 1, 1
  }
};

#endif


user4143: The simple answer is: don't.
At the moment you are trying to assign integers to chars, and that just won't fit. It's like a round peg in a square hole. Or more like trying to force a bowling pin through a hose pipe. It just isn't going to fit.
So you either need to "print" the values into your final string (say with sprintf()) or just don't build up a string at all and print the values directly. And while you're at it, use some loops to make your code simpler:
for (int i = 0; i < 14; i++) {
    Serial.print(Mod_current[i]);
    Serial.print(",");
}

for (int i = 23; i > 13; i--) {
    Serial.print(Mod_current[i]);
    Serial.print(",");
}

Serial.print(Temp_read);
Serial.print(",");
Serial.print(HV_Read);
Serial.print(",");
Serial.print(SPD);
Serial.print(",");
Serial.println(DISCONNECTOR);

If you really need to create a string the easiest way is probably with sprintf (or snprintf to prevent buffer overflows):
char sendBuffer[200]; // Enough room for 28 integers of 1-5 characters, plus commas.

snprintf(sendBuffer, 200, "%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
    Mod_current[0], Mod_current[1], Mod_current[2], Mod_current[3],
    Mod_current[4], Mod_current[5], Mod_current[6], Mod_current[7],
    Mod_current[8], Mod_current[9], Mod_current[10], Mod_current[11],
    Mod_current[12], Mod_current[13], Mod_current[14], Mod_current[23],
    Mod_current[22], Mod_current[21], Mod_current[20], Mod_current[19],
    Mod_current[18], Mod_current[17], Mod_current[16], Mod_current[15],
    Mod_current[14], Temp_read, HV_Read, SPD, DISCONNECTOR);

int len = strlen(sendBuffer);
Serial.println(sendBuffer);
Serial.print(len);
Serial.println(" bytes");

(note: I think I got the right number of parameters there)

904: <p>I have my Arduino code as below.I am trying to send Serial request and get response for it. I can able to send request mentioned in Setup function and also able to switch cases. Problem i am facing Print character buffer after storing the  values. can someone suggest me how to store integer value into charcter buffer and print result later.</p>

<pre><code>#include "glob.h"
const int BUFFER_SZ = 32;
char sendBuffer[60]={'0'};

void Take_Reading() {

  for (int row = 0; row &lt; 8; row++)
  {
    //   // get rid of me:
    digitalWrite(SO_enable, array[row][0]);
    digitalWrite(S1_enable, array[row][1]);
    digitalWrite(S2_enable, array[row][2]);
    delay(50);
    analog_1_pv[row] = ANALOG_SCALING * analogRead(A0);
    analog_2_pv[row] = ANALOG_SCALING * analogRead(A1);
    analog_3_pv[row] = ANALOG_SCALING * analogRead(A2);
    if ( (analog_1_pv[row] &lt;= MINV_RANGE || (analog_1_pv[row] &gt;= MAXV_RANGE) ))
    {
      Current_Value1[row] =  0.0;
    }
    else
    {
      Current_Value1[row] =  (analog_1_pv[row] * 12.5) - 31.25;

    }

    if (  (analog_2_pv[row] &lt;= MINV_RANGE || (analog_2_pv[row] &gt;= MAXV_RANGE) ))
    {
      Current_Value2[row] =  0.0;
    }
    else
    {
      Current_Value2[row] =  (analog_2_pv[row] * 12.5) - 31.25;

    }

    if (  (analog_3_pv[row] &lt;= MINV_RANGE || (analog_3_pv[row] &gt;= MAXV_RANGE) ))
    {
      Current_Value3[row] =  0.0;
    }
    else
    {
      Current_Value3[row] =  (analog_3_pv[row] * 12.5) - 31.25;

    }


    Mod_current[row] = (uint16_t)(Mul_Factor * Current_Value1[row]);
    Mod_current[row + 8] = (uint16_t)(Mul_Factor * Current_Value2[row]);
    Mod_current[row + 16] = (uint16_t)(Mul_Factor * Current_Value3[row]);


  }

}









int ID_Check() {

  int ID_value;
  for (int row = 0; row &lt; 8; row++)
  {
    digitalWrite(SO_enable, array[row][0]);
    digitalWrite(S1_enable, array[row][1]);
    digitalWrite(S2_enable, array[row][2]);
    Status_Out[row] = digitalRead(Output_Read);

  }

  ID_value = 1 * Status_Out[7] + 2 * Status_Out[6] + 4 * Status_Out[5] + 8 * Status_Out[4] + 16 * Status_Out[3] + 32 * Status_Out[2] + 64 * Status_Out[1] + 128 * Status_Out[0];
  return (ID_value);

}




int  Take_Temp_Reading()
{

  Temp_Total = Temp_Total - Temp_readings[Temp_index];
  Temp_readings[Temp_index] = analogRead(A5);
  Temp_Total = Temp_Total + Temp_readings[Temp_index];
  Temp_index = Temp_index + 1;

  if (Temp_index &gt;= numReadings)
  {
    Temp_index = 0;
    Temp_Average = Temp_Total / numReadings;
  }
  temp = (Temp_Average * 5.0) / 1023.0;


  //  temp = float(analogRead(A5)) * 5.0 / 1024.0;
  temp_int = (int)(temp * 100.0);
  return (temp_int);
  // Serial.print("Temp"); Serial.println(temp);
}

int SPD_Check()
{

  SPD_STATUS = digitalRead(SPD_STATUS_PIN);
  return (SPD_STATUS);
}

int  DC_Status()
{

  DC_STATUS = digitalRead(DC_STATUS_PIN);
  return (DC_STATUS);

}



int   Take_HV_Reading()
{

  //int analog_int= analogRead(A4);

  total = total - readings[index];
  // read from the sensor:
  readings[index] = analogRead(A4);
  // add the reading to the total:
  total = total + readings[index];
  // advance to the next position in the array:
  index = index + 1;

  // if we're at the end of the array...
  if (index &gt;= numReadings1)
  {
    index = 0;
    average = total / numReadings1;

  }
  else
  {

    HV_voltage = (average * 5.0) / 1023.0;
  }
  if (HV_voltage &lt;= 0.25)
  {

    Conv_HV_voltage = 0.0;
  }
  else
  {
    Conv_HV_voltage = 197.837837838 * HV_voltage + 10.8108108108;
  }

  HV_Reading = (uint16_t)(Conv_HV_voltage * 10);

  //  HV_Reading = (uint16_t)(Conv_HV_voltage * 10);

  return(HV_Reading);
}


void  Serial_Command1()

{
   Take_Reading();
  int Temp_read=Take_Temp_Reading();
  int HV_Read=Take_HV_Reading();
  SPD=SPD_Check();
  DISCONNECTOR=DC_Status();
  Serial.println("Command1 executed ");


  sendBuffer[1]=char(Mod_current[1]) ;
  sendBuffer[2]= ',';
  sendBuffer[2]= Mod_current[1];
  sendBuffer[3]= ',';

  sendBuffer[4]= Mod_current[2];
  sendBuffer[5]= ',';
  sendBuffer[6]= Mod_current[3];
  sendBuffer[7]= ',';

  sendBuffer[8]= Mod_current[4];
  sendBuffer[9]= ',';
  sendBuffer[10]= Mod_current[5];
  sendBuffer[11]= ',';

  sendBuffer[12]= Mod_current[6];
  sendBuffer[13]= ',';
  sendBuffer[14]= Mod_current[7];
  sendBuffer[15]= ',';

  sendBuffer[16]= Mod_current[8];
  sendBuffer[17]= ',';
  sendBuffer[18]= Mod_current[9];
  sendBuffer[19]= ',';

  sendBuffer[20]= Mod_current[10];
  sendBuffer[21]= ',';
  sendBuffer[22]= Mod_current[11];
  sendBuffer[23]= ',';


  sendBuffer[24]= Mod_current[12];
  sendBuffer[25]= ',';
  sendBuffer[26]= Mod_current[13];
  sendBuffer[27]= ',';

  sendBuffer[28]= Mod_current[23];
  sendBuffer[29]= ',';
  sendBuffer[30]= Mod_current[22];
  sendBuffer[31]= ',';

  sendBuffer[32]= Mod_current[21];
  sendBuffer[33]= ',';
  sendBuffer[34]= Mod_current[20];
  sendBuffer[35]= ',';

  sendBuffer[36]= Mod_current[19];
  sendBuffer[37]= ',';
  sendBuffer[38]= Mod_current[18];
  sendBuffer[39]= ',';

  sendBuffer[40]= Mod_current[17];
  sendBuffer[41]= ',';
  sendBuffer[42]= Mod_current[16];
  sendBuffer[43]= ',';

  sendBuffer[44]= Mod_current[15];
  sendBuffer[45]= ',';
  sendBuffer[46]= Mod_current[14];
  sendBuffer[47]= ',';
  sendBuffer[48]= Temp_read;
  sendBuffer[49]= ',';
  sendBuffer[50]= HV_Read;
  sendBuffer[51]= ',';
  sendBuffer[52]= SPD;
  sendBuffer[53]= ',';
  sendBuffer[54]= DISCONNECTOR;

  Serial.println(sendBuffer[1]);

}

void Serial_Command2(int a)
{

  Serial.print("Command2 executed: ");
  Serial.println(a);
}





void setup()
{
  Serial.begin(57600);
  Serial.println("Format 1: &lt;SMCB1,1&gt;");
  Serial.println("Format 2: &lt;SMCB1,1,Length&gt;");

}

// Parse the request, WITHOUT the '&lt;' and '&gt;' delimiters.
void parseRequest(char *request)
{
  // Check the request starts with the prefix "SMCB1,1".
  if (strncmp(request, "SMCB1,1", 7) != 0) {
    Serial.println(F("Error: bad request prefix"));
    return;
  }

  // Remove that known prefix.
  // Now we have either "", ",Length" or ",Timer,On_OFF"
  request += 7;

  // Format 1: ""
  if (request[0] == '\0') {
    //Serial.println(F("Received format 1"));
    Serial_Command1();
    return;
  }

  // Remove the leading comma.
  // Now we have either "Length" or "Timer,On_OFF"
  if (request[0] != ',') {
    Serial.println(F("Error: ',' expected"));
    return;
  }
  request++;

  // Format 2: "Length", no comma.
  char * comma = strchr(request, ',');
  if (!comma) {

    int length = atoi(request);
    Serial_Command2(length);
    //Serial.print(F("Received format 2, length = "));
    // Serial.println(length);
    return;
  }


}

void loop()
{
  static char buffer[BUFFER_SZ];  // received chars
  static size_t pos;              // current position in buffer
  static bool insideRequest;      // are we between '&lt;' and '&gt;'?

  if (Serial.available()) {
    char c = Serial.read();
    if (insideRequest) {
      if (c == '&gt;') {  // end of request received
        buffer[pos] = '\0';  // terminate the string
        parseRequest(buffer);
        pos = 0;             // get ready for the next request
        insideRequest = false;
      }
      else if (pos &lt; BUFFER_SZ-1) {  // add char to buffer
        buffer[pos++] = c;
      }
    }
    else if (c == '&lt;') {  // start of request
      insideRequest = true;
    }
  }
}
</code></pre>

<p>Golb.h header file contains</p>

<pre><code>#ifndef GLOB_H
#define GLOB_H
int counter=0;
int Mod_current[24];
const int numReadings = 10;
const int numReadings1 = 10;
int Temp_Total = 0;
int Temp_readings[numReadings];
int Temp_index = 0;
int Temp_Average = 0;
float  reading[10];
float Total = 0.0;
static int i;

int readings[numReadings];
int index = 0;
int total = 0;
int average = 0;

// These PinS are use to enable and disable analog MUX
int SO_enable = 5;
int S1_enable = 4;
int S2_enable = 3;

// temprature sensor permeter
int TempPin = 5;
float temp;
static int temp_int;

// digital mux setting
int Output_Read = 2;

float Vref = 2.5;
// Used for sensor conversion
float ANALOG_SCALING = 0.004887585532746823;
//tempfloat ANALOG_SCALING=0.0049560117;


int Sensor_Value0 = 0;
int Sensor_Value1 = 0;
int Sensor_Value2 = 0;
float analog_1_pv[8];
float analog_2_pv[8];
float analog_3_pv[8];
int Status_Out[8];

//SPD &amp; DC STATUS PIN
static int SPD_STATUS_PIN = 6;
static int DC_STATUS_PIN = 7;

int row;

int Mul_Factor = 10;

float Current_Value1[8] = {
  0.0
};
float Current_Value2[8] = {
  0.0
};
float Current_Value3[8] = {
  0.0
};

//HV perameter setting are defined here
int HV_SensorValue;
int HV_Reading;
float HV_voltage;
float Conv_HV_voltage;
unsigned  int DC_STATUS = 0;
unsigned int SPD_STATUS = 0;
float MINV_RANGE = 2.52;
//float MIDV_RANGE1=1.875;
float MAXV_RANGE = 4.5;

int SPD;
int DISCONNECTOR;


int Serial_Status=0;




int array[8][3] = {
  {
    0, 0, 0
  }
  , {
    0, 0, 1
  }
  , {
    0, 1, 0
  }
  , {
    0, 1, 1
  }
  , {
    1, 0, 0
  }
  , {
    1, 0, 1
  }
  , {
    1, 1, 0
  }
  , {
    1, 1, 1
  }
};

#endif
</code></pre>
 4143: <p>The simple answer is: don't.</p>

<p>At the moment you are trying to assign integers to chars, and that just won't fit. It's like a round peg in a square hole. Or more like trying to force a bowling pin through a hose pipe. It just isn't going to fit.</p>

<p>So you either need to "print" the values into your final string (say with <code>sprintf()</code>) or just don't build up a string at all and print the values directly. And while you're at it, use some loops to make your code simpler:</p>

<pre><code>for (int i = 0; i &lt; 14; i++) {
    Serial.print(Mod_current[i]);
    Serial.print(",");
}

for (int i = 23; i &gt; 13; i--) {
    Serial.print(Mod_current[i]);
    Serial.print(",");
}

Serial.print(Temp_read);
Serial.print(",");
Serial.print(HV_Read);
Serial.print(",");
Serial.print(SPD);
Serial.print(",");
Serial.println(DISCONNECTOR);
</code></pre>

<p>If you really need to create a string the easiest way is probably with <code>sprintf</code> (or <code>snprintf</code> to prevent buffer overflows):</p>

<pre><code>char sendBuffer[200]; // Enough room for 28 integers of 1-5 characters, plus commas.

snprintf(sendBuffer, 200, "%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
    Mod_current[0], Mod_current[1], Mod_current[2], Mod_current[3],
    Mod_current[4], Mod_current[5], Mod_current[6], Mod_current[7],
    Mod_current[8], Mod_current[9], Mod_current[10], Mod_current[11],
    Mod_current[12], Mod_current[13], Mod_current[14], Mod_current[23],
    Mod_current[22], Mod_current[21], Mod_current[20], Mod_current[19],
    Mod_current[18], Mod_current[17], Mod_current[16], Mod_current[15],
    Mod_current[14], Temp_read, HV_Read, SPD, DISCONNECTOR);

int len = strlen(sendBuffer);
Serial.println(sendBuffer);
Serial.print(len);
Serial.println(" bytes");
</code></pre>

<p>(note: I think I got the right number of parameters there)</p>
