I am just starting with this board and though I have programmed in the past I can't get a simple integer variable to work..
Here is a snippet of code pared down as far as I can. At the x=x+1 I get an error that "x was not declared in this context" I have looked at the reference and a few examples and can't seem to get around this simple hurdle..
void setup() {
// put your setup code here, to run once:
int x = 0;
}
void loop() {
// put your main code here, to run repeatedly:
x=x+1;
}
The word to search for is "scope". In your code, x has "local scope" (also called a "local variable" or "automatic variable" or "auto variable"). In this code, x has "global scope" (also called a "global variable")...
int x = 0; // Not defined inside of a function but rather in "no man's land".
void setup() {
// put your setup code here, to run once:
}
void loop() {
// put your main code here, to run repeatedly:
x=x+1;
}
Variables declared inside of a function can only be used in that function. setup() and loop() are functions.
You are declaring x in setup() and trying to use it in loop(). That is called being "out of scope", which is what the compiler is telling you...
Try making your variable "global."
Thanks James and Coding Badly...!
I knew it had to be something simple. I think my old Basic was showing and I also had the idea that void setup was where I was making it global....Have to go back and look at some examples after I know what I am looking for.
Garry
int count = 0; // this variable is global to the sketch
void setup() {
int i; // this variable is local to setup(), i.e. it doesn't exists outside setup() function
for (i = 0; i < 3; i++) {
Serial.print(i);
Serial.print(",");
Serial.println(count);
count++;
}
}
void loop() {
int i; // this is local to loop() function, it's completely unrelated to the i variable declared in setup()
for (i = 0; i < 3; i++) {
Serial.print(i);
Serial.print(",");
Serial.println(count);
count++;
}
delay(2000);
}
It should print:
0,0
1,1
2,2
0,3
1,4
2,5
0,6
1,7
2,8
etc.
HTH