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Forum Index : Microcontroller and PC projects : Question about keyboard input

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RCMAN
Newbie

Joined: 31/10/2020
Location: Canada
Posts: 29
Posted: 03:36pm 06 Dec 2020
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Hello,

I'm writing a shooting game and I find the CMM2 doesn't accept multiple key presses at the same time.

If I want to control ship movement and press fire at the same time I need to stop moving my ship for it to register another key.

Is there an interupt driven way I can get keyboard input?

I have used keydown and inkey$ and neither seem to allow multiple.

Thanks
RC
 
NPHighview

Senior Member

Joined: 02/09/2020
Location: United States
Posts: 213
Posted: 03:48pm 06 Dec 2020
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I've noticed this as well; "N-key" rollover doesn't work very well on the CMM2.  You can detect a few combination keypresses (Ctrl-arrow keys) in particular, but that's pretty much it.  But, with today's release with Peter working on USB keyboard "up key" detection, it may be worth revisiting.

I wrote a little keyboard monitoring program to display all seven or eight of the values in the keydown() array, and took notes on what key combos work.  This should be pretty easy to replicate (I'm not at my development computer right now).
Live in the Future. It's Just Starting Now!
 
RCMAN
Newbie

Joined: 31/10/2020
Location: Canada
Posts: 29
Posted: 04:09pm 06 Dec 2020
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  NPHighview said  I've noticed this as well; "N-key" rollover doesn't work very well on the CMM2.  You can detect a few combination keypresses (Ctrl-arrow keys) in particular, but that's pretty much it.  But, with today's release with Peter working on USB keyboard "up key" detection, it may be worth revisiting.

I wrote a little keyboard monitoring program to display all seven or eight of the values in the keydown() array, and took notes on what key combos work.  This should be pretty easy to replicate (I'm not at my development computer right now).



I have tried left control and it would not show me anything. I'm not sure why.

I have a similar program that just shows values. I read in the Beta 1 of the firmware this might have been addressed but I have not confirmed.

RC
 
matherp
Guru

Joined: 11/12/2012
Location: United Kingdom
Posts: 10589
Posted: 04:27pm 06 Dec 2020
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keydown works perfectly within the limitations of the keyboard itself. Keyboards use a matrix scan and depending on where keys are in the matrix they may or may not be able to appear simultaneously

Run the attached to see what your keyboard can do and read the manual for what to expect

do
print @(0,0),str$(keydown(0),4), str$(keydown(1),4),str$(keydown(2),4),str$(keydown(3),4),str$(keydown(4),4),str$(keydown(5),4),str$(keydown(6)),bin$(keydown(7),8)
loop

Edited 2020-12-07 02:27 by matherp
 
RCMAN
Newbie

Joined: 31/10/2020
Location: Canada
Posts: 29
Posted: 04:39pm 06 Dec 2020
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  matherp said  keydown works perfectly within the limitations of the keyboard itself. Keyboards use a matrix scan and depending on where keys are in the matrix they may or may not be able to appear simultaneously

Run the attached to see what your keyboard can do and read the manual for what to expect

do
print @(0,0),str$(keydown(0),4), str$(keydown(1),4),str$(keydown(2),4),str$(keydown(3),4),str$(keydown(4),4),str$(keydown(5),4),str$(keydown(6)),bin$(keydown(7),8)
loop


Thank you. That solved the issue.

RC
 
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