Arduino Serial parsing - c++

Question

I'm working on an Arduino sketch and I'm trying to change a variable with serial. I'm using some example code that I found on arduino.cc to start with. I'm trying to modify the code with an "if statement" to update a variable timevar with integerFromPC; the problem I'm having is if I type a number higher than 4 digits like 99999 it prints out the wrong data and the variable timevar doesn't get updated correctly? I'm not sure what to do?
unsigned long timevar = 1000000;
const byte numChars = 32;
char receivedChars[numChars];
char tempChars[numChars]; // temporary array for use when parsing
// variables to hold the parsed data
char messageFromPC[numChars] = {0};
int integerFromPC = 0;
int ifpc = 0;
float floatFromPC = 0.0;
boolean newData = false;
//============
void setup() {
Serial.begin(9600);
Serial.println("This demo expects 3 pieces of data - text, an integer and a floating point value");
Serial.println("Enter data in this style <HelloWorld, 12, 24.7> ");
Serial.println();
}
//============
void loop() {
recvWithStartEndMarkers();
if (newData == true) {
strcpy(tempChars, receivedChars);
// this temporary copy is necessary to protect the original data
// because strtok() used in parseData() replaces the commas with \0
parseData();
showParsedData();
newData = false;
}
}
//============
void recvWithStartEndMarkers() {
static boolean recvInProgress = false;
static byte ndx = 0;
char startMarker = '<';
char endMarker = '>';
char rc;
while (Serial.available() > 0 && newData == false) {
rc = Serial.read();
if (recvInProgress == true) {
if (rc != endMarker) {
receivedChars[ndx] = rc;
ndx++;
if (ndx >= numChars) {
ndx = numChars - 1;
}
}
else {
receivedChars[ndx] = '\0'; // terminate the string
recvInProgress = false;
ndx = 0;
newData = true;
}
}
else if (rc == startMarker) {
recvInProgress = true;
}
}
}
//============
void parseData() { // split the data into its parts
char * strtokIndx; // this is used by strtok() as an index
strtokIndx = strtok(tempChars,","); // get the first part - the string
strcpy(messageFromPC, strtokIndx); // copy it to messageFromPC
strtokIndx = strtok(NULL, ","); // this continues where the previous call left off
integerFromPC = atoi(strtokIndx);
strtokIndx = strtok(NULL, ",");
floatFromPC = atof(strtokIndx); // convert this part to a float
}
//============
void showParsedData() {
if (strcmp(messageFromPC, "set time") == 0)
timevar = integerFromPC;
Serial.print("Time Set To ");
Serial.println(integerFromPC);
Serial.println(timevar);
}
//do other stuff

Answer 1

You declare int integerFromPC. int on Arduino is 16 bits. 99999 doesn't fit into 16 bits, so will appear mod 2^16 as 34463. Use long instead as you do for timeVar and it will be ok for up to +/- 2^31 .