Chief Delphi - Inverting Y axis on joystick

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FormatteD_C

24-02-2004 16:22

Inverting Y axis on joystick

Hey,
We need to invert the Y axis and I don't know how I would code it, any input on this would be great.

JoshJ

24-02-2004 16:25

Re: Inverting Y axis on joystick

All you have to do is subtract your current value from 254. I think you can just do p1_y=254-p1_y; but just to be safe I would use a temp variable. Sooo, temp=254-p1_y; then just use temp instead of p1_y (or whatever joystick port) in your program.

Astronouth7303

24-02-2004 16:40

Re: Inverting Y axis on joystick

Woulden't it be temp = 255 - p1_y? Because other wise you can have negative numbers.

FotoPlasma

24-02-2004 16:42

Re: Inverting Y axis on joystick

Quote:

Originally Posted by Astronouth7303

Woulden't it be temp = 255 - p1_y? Because other wise you can have negative numbers.

If p1_y == 0, then that would evaluate to 255, which is an invalid PWM output. If you're using an unsigned data type, it can't be negative, anyway.

Astronouth7303

24-02-2004 16:47

Re: Inverting Y axis on joystick

Oh, right. But I think the joystick vals go up to 255.

deltacoder1020

24-02-2004 16:51

Re: Inverting Y axis on joystick

Code:



temp = (p1_y == 255) ? 0 : (254 - p1_y);

jeremy562

24-02-2004 16:52

Re: Inverting Y axis on joystick

255 is not a valid output on a PWM. I think 3 consecutive 255's result in a reset or something.

The range is 0-254, so you want:

p1_y = 254 - p1_y;

No need for a temp variable, the compiler will handle that just fine.

Astronouth7303

24-02-2004 16:56

Re: Inverting Y axis on joystick

Ok, thank you for correcting me. Though I could've sworn I saw 255 on dashboard... :confused: Oh, well :shrug:

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