Arduino Gcode reader - arduino

Question

I made G-code reader on Arduino, but it stops reading. It has many "break;" and I have also many while loops and switches, so I'm thinking that when I break on loop/switch, it will break all.
Another idea is that it goes some kind of loop, but I can't figure out where it loops.
Here is my code:
void Gcode(){
String yy,xx,gg;
char text[64];
int number=1;
while(number!=3){
while (Serial.available()>0) {
delay(3); //delay to allow buffer to fill
char c = Serial.read();
Serial.println(c);
switch(c){
case 'G':
//read_number()
while (Serial.available()>0) {
char k = Serial.read();
if(k==' ' || k=='\n'){
break;
}
else{
gg+=k;
}
}
switch(gg.toInt()){
case 1:
Serial.println(gg);
while (Serial.available()>0) {
c = Serial.read();
Serial.println(c);
switch(c){
case 'X':
while (Serial.available()>0) {
char k = Serial.read();
if(k==' ' || k=='\n'){
break;
}
else{
xx+=k;
}
}
char buf[xx.length()];
xx.toCharArray(buf,xx.length());
x2=atof(buf);
Serial.println(x2);
break;
case 'Y':
while (Serial.available()>0) {
char k = Serial.read();
if(k==' ' || k=='\n'){
break;
}
else{
yy+=k;
}
}
Serial.println(yy);
char buf2[yy.length()];
yy.toCharArray(buf2,yy.length());
y2=atof(buf2);
break;
case 'E':
break;
case 'F':
break;
default:
Serial.print("the end");
}
Serial.print("out of switch");
}
break;
case 2:
break;
default:
Serial.print("nothing");
}
break;
case '\n':
number=3;
break;
default:
Serial.print("default");
}
}
}
if(sizeof(yy)>0){
yy="";
xx="";
gg="";
}
Serial.print("quit");
}
When I send G1 X10.00 Y-100.00 \n It prints only:
G
1
X
10.00
out of s

Answer 1

one of your big problem is that your while end when thwere are nomore carachter. This mean that if your loop consume the buffer FASTER than it get written (remeber:9600 baud mean 960Byte/s, arduino even if slow but can compute 16.000.000 operation/s...).
Another big problem MAY bethe lack of ram, os your output is truncated. there is some function to check real time usage of ram, see http://playground.arduino.cc/Code/AvailableMemory, stopping to use String and even char array is a way better idea; the code is not that hard to write!
so the pc would send "G1 X10.00 Y-100.00 \n"
but at time X your aruino get "G1 X10.00", if you read really fast the buffer now (faster than 1/960 of a second, arduino is a way faster than that!)
so ideally you should change all your while condition removing serial available but instead putting the condition you use in the if with the break; sothe first while from
while (Serial.available()>0)
became
while ( (k=Serial.read()) != ' ' && k != '\n') //yes it is a bit weird like this
maybe a little better, with check that k is a valid caracter, AND timeout
unsigned long timeout_ms = 1000; //timeout after 1 seconds from NOW!
unsigned long start_ms = millis();
int k=Serial.read();
while ( k != ' ' && millis()-start_ms < timeout_ms){// because here we expect "Gx ", why are you was also using k != '\n'? removed, feel free to add it back
if (k == -1){
k=Serial.read(); //read the next char
continue; //return to the beginning of the while
}
[... do thigs...]
k=Serial.read(); //read the next char
//here you may add "start_ms = millis();" if you want to reset the timeout
}