Parsing Arduino Receiving Strings

Question

I'm currently using google geolocation to get location data to one nodemcu and sending it through serial to another Arduino. The serial command I'm getting right now is,

1.450187T103.824745 

I'm using the following code to parse it.

 if (Serial.available()) {
 char c = Serial.read(); //gets one byte from serial buffer
 //if (c == '\n') { //looks for end of data packet marker
 if (c == '\n') {
 // Serial.println(readString); //prints string to serial port out
 //do stuff 
 substring = readString.substring(0,8);
 lati = substring;
 loc = readString.indexOf("T");
 substring = readString.substring(loc+1, loc+11);
 longi = substring;
 readString=""; //clears variable for new input
 substring=""; 
 } 
 else { 
 readString += c; //makes the string readString
 }
 }

It works most of the time but sometimes I get 'T' inside the string as well. like this

lat=1.450146&longi=102464T103

What's wrong in my code?

• jsotola: what is the reason for transmitting the H? ... you only need the T to separate the two values
• chrisl: Can you show us the actual serial String, that you received in that case?

Answer 1

with readBytesUntil and C string

if (Serial.available()) {
 char buff[32];
 int l = Serial.readBytesUntil('\n', buff, sizeof(buff));
 if (l > 0 && buff[l - 1] == '\r') {
 l--; // to remove \r if it is there
 }
 buff[l] = 0; // terminate the string
 char* p = strchr(buff,'T'); // returns pointer in string
 if (p != NULL) {
 *p = 0; // write 0 as char at pointer to terminate the first part
 p++; // move the pointer to next char
 Serial.println(buff);
 Serial.println(p);
 } else {
 Serial.println(buff);
 }
}