Absolute mouse coordinates

Official Hardware Mega Due
1

I need to send absolute coordinates to host PC from the HID mouse i emulated on SAM processor on Due board. To do this i tried to change the HID report descriptor in Mouse.cpp. Following are the changes i made :

#ifdef ABSOLUTE_MOUSE_MODE
    0x15, 0x01,                    //     LOGICAL_MINIMUM (1)       <<<< This allows us to talk to any display resolution
    0x25, 0x64,                    //     LOGICAL_MAXIMUM (100)     <<<<  as though it was 100x100 pixels
    0x75, 0x08,                    //     REPORT_SIZE (8)
    0x95, 0x03,                    //     REPORT_COUNT (3)
    0x81, 0x02,                    //     INPUT (Data,Var,Abs)      <<<< This allows us to moveTo absolute positions
#else
    0x15, 0x81,                    //     LOGICAL_MINIMUM (-127)
    0x25, 0x7f,                    //     LOGICAL_MAXIMUM (127)
    0x75, 0x08,                    //     REPORT_SIZE (8)
    0x95, 0x03,                    //     REPORT_COUNT (3)
    0x81, 0x06,                    //     INPUT (Data,Var,Rel)
#endif

This made no improvement. leaving stray characters in Mouse.cpp, it compiled. Doesn't look like this is the file used. I changed c:\Program Files(x86)\Arduino\libraies\Mouse\src\Mouse.cpp
Is this the right file ?

Second part of problem: I do not see my mouse at all, looks like frozen. I just did a cursor movement loop as follows:

for(i=1; i<127; i++)
for(j=1; j<127; j++)
Mouse.move(i,j);

This doesn't work either. I have sucessfully added keyboard.Mouse is just not working. The above is with absolute coordinates. I'm a newbie to arduino so kindly bear with me.

Thanks,
Srinivas

2

A physical mouse is not very accurate. The user moves the mouse until the mouse cursor on screen is where it should be. That's why mouse moves are treated as relative. Absolute coordinates can be used with graphic tablets or touch screens with a fixed raster of sensitive points.

3

is ABSOLUTE_MOUSE_MODE defined?

4

Yes, it is defined.
Does it suffice to simply change that file and compile the sketch ? Or should i compile the library separately ?

5

FIgured out i was changing the wrong file. It works now, Thank you.

6

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