Keyboard/Mouse question.

RicardoP

Hello!

I've been thinking about this little project and finally I decided to do it. But there are a couple paths that I could take (probably more but anyway ... ) and I would like to get some advice on.

Basically I need keyboard/mouse input, the gotcha is that it needs to be as fast a possible (meaning I don't want much/any delay between the key press and the time the prop does something with it.

Route a)
Use a ps2 hookup directly to the prop, this would probably give fastest response time.

Route b)
Use a pc, read the kb/mouse data and send it to the prop via serial connection.

Route A seems obvious but Route B has a cool advantage ... I can write a nice front end that would allow remapping of the keys (user presses 'W' for example and the program remaps it to some other key)

Thanks!

Spork Frog

Obviously the former will be faster. Of course, as well, you can re-map the keys within your program. No one says that "W" actually has to show "W" in the end. Of course, that could mean somewhat large tables of re-mapping. Although, in the end re-mapping on the prop directly would still be easier (I'd think) than trying to do it with a PC. Then it's self-contained as well.

RicardoP

Could serial communications be done fast enough that the delay wouldn't be something a human would notice?

Graham Stabler

There is no noticable lag when using the keyboard object.

Graham

hippy

It seems overkill to add a PC to do a job the Propeller can. A keyboard lookup table should not be overly large, and it would run far quicker than a PC application routing via serial.

If you wanted / needed to off-load work from a Propeller, you could always use another Propeller instead of a PC. Far cheaper, more 'planet friendly'.

RicardoP said...
Could serial communications be done fast enough that the delay wouldn't be something a human would notice?

In tests I once did, few perceived a delay between pushing a button and a LED coming on 100mS later. It takes around 20mS for a character received to be shown on a monitor. Serial comms would run far faster than that, so the answer is the delay would not be noticeable.

Post Edited (hippy) : 9/17/2007 11:59:50 PM GMT

Ariba

RicardoP said...

Route b)
Use a pc, read the kb/mouse data and send it to the prop via serial connection.

This is exactly was PropTerminal does. Try it out to decide if this way is fast enough for you:
http://forums.parallax.com/showthread.php?p=649540

Andy

Mark Bramwell

You could also look at Color-Code.spin that I posted yesterday. You use your PC with hyperterminal at 9600 baud. The I,J,K,M keys each cause the propeller to perform a function on the screen. Is there a delay?

There 2 versions of the program in the zip file. One uses a PS2 keyboard plugged into the protoboard, the other is serial. I believe those 2 programs should be able to answer your questions.

RicardoP

Thanks all for your replies. I will try all the suggestions and see what works best.