Issues with variables dimentions

Projects Programming
1

Hello,
I'm working on a robotic project and I'm trying to implement inverse kinematics.
My issue is that, with an Arduino Uno R3, I can't seem to figure out how to work with big numbers.
An example would be 2147299: the correct result is 87906 but the arduino displays 22370 as the result. This result is given when using a long variable, which should go as far as 2^35.
I don't really know what the problem could be and I can't seem to find any solution online.
If anyone has any idea why this is happening, it would help me a lot!
Thanks
P.S. I'll be inserting the basic code I estrapulated from the more complex code of my project in order to examine better the problem

long a;

void setup() {
  Serial.begin(9600);
  a = 2*147*299;
  Serial.println(a);
}

void loop() {

}
2

0 to 2^32 for unsigned long. -(2^31) to (2^31-1) for long.

uint32_t a;

void setup() {
  Serial.begin(115200);
  a = 2*147*299UL;
  Serial.println(a);
}

void loop() {

}
3

That's great, thank you so much. The code works but I can't seem to make it work if I use variables instead of the three values inside the multiplication.
Is this a syntax error?

uint32_t a;
int b = 147;
int c = 299;
int d = 2;

void setup() {
  Serial.begin(9600);
  a = b*c*d UL;
  Serial.println(a);
}

void loop() {

}
4

What did the compiler say about it?

6

The compiler doesn’t signal any error but still does the calculation wrong

7

That’s perfect, It works perfectly now.
Thank you to all of you!

8

Are you sure? I get this because the UL is only for integer literal constants:

sketch_mar11a:8:13: error: expected ';' before 'UL'
   a = b*c*d UL;
             ^~
exit status 1
expected ';' before 'UL'

Why not just use the an appropriate datatype to begin with?

uint32_t a;
uint32_t b = 147;
uint32_t c = 299;
uint32_t d = 2;

void setup() {
  Serial.begin(115200);
  a = b*c*d;
  Serial.println(a);
}

void loop() {
}