Absolute Value of Joystick position

Technical C/C++
1

The joysticks I have are somewhat off center slightly so the drive motors are constantly running at like .05 as an example.

This is what I am trying to do below but I think the Abs() function converts it to an Integer. How can I use it on a float (or should I resort to more “or’s” in the “if’s”


if(abs(J_stick1.GetY()) <= .05 || abs(J_stick2.GetY()) <= .05)
     R_myRobot.Drive(0.0, 0.0);
2

My copy of K&R says that fabs()* should be part of the C ANSI standard library.

  • fabs() = floating point absolute value

3

error: `fabs’ undeclared (first use this function)

This is the message I get when trying to use fabs() where i have abs() in the previous post

4

Sounds like you are missing this:

#include "Math.h"
5

Thanks, I built it and it didn’t produce an error. I will have to wait to test in a week because we sealed the bot and we are making an extra bot.

I will see if i can test it on this 1 scrap bot some day before then hopefully.

Thanks,
Davis

6