TOKN KB16 ENCODERS

[CheffoJeffo]

This group of threads was launched by a registered user of
your forum with the primary intent of denigrating a competitor's
product. This type of sleaze marketing is common and unfortunately
a gross misuse of public domain.

Do I understand you correctly -- you are saying that all of these threads were started by a single user (using new registrations) for the intent of hurting your product ?

Strange ... I always suspected that they were planted by someone wanting to help your product, but that it kinda backfired because for most frankenpanel builders or those who need to remap keys regularly (like, I suspect, most of the folks here), your product isn't the best choice (IMPO, of course).

Cheers.

[Tiger-Heli]

Listen, Randy, I appreciate your valiant attempts to protect BYOAC users from other encoders, but I'm not going to keep up this thread and help your witch hunt.

That was a little uncalled for IMHO.

We have now established that the KB16 uses a matrix (after Kev's reply was posted).

Matrix encoders CAN exhibit ghosting or blocking.  Note that I said CAN, not that the KB16 DOES, which I would consider unlikely.

See http://www.mameworld.net/emuadvice/keyhack2.html under "LITTLE KNOWN FACTS AND COMMON MISCONCEPTIONS:" or the shorter explanation at http://www.dribin.org/dave/keyboard/

Blocking is the easiest to test for:  Simply connect all 16 inputs, run GhostKey or other similar software and see if 16 keypresses show up.  However, blocking is typically only used to prevent ghosting from showing up, so it is unlikely to be used on the KE16.

Ghosting is harder to test for.  The easiest method is to randomly press key combinations and see if you ever see a key register that was NOT pressed.  The scientific method is to map out the matrix (either with a multi-meter or through the traces on the board), and then activate three keys on the same row and column and see if a fourth keypress is displayed.

From keyboard hacking, if blocking or a pressed-key limit is not employed, ghosting can be controlled by the use of diodes, but Mattp earlier stated that his design does not use these.

Actually, another concern is masking (I came up with a way to avoid ghosting without diodes, off the top of my head, but I don't think it will work in practice).

Lets say my matrix is defined as follows:

     1    2

1   A    B

2  C     D

Without diodes, pressing A, B, C, and will result in a D output being generated, but I could have D permanently set to not output a code. But masking means that if I release the C key, the output will still register until I release one of the other keys.

Been I while since I reviewed all this, but it should be accurate.

(Also, I would guess that the KB16 does use diodes or some electronic equivalent and avoids these problems, but I have no first-hand knowledge, nor way, nor time to test.)

[Tiger-Heli]

Thank you Kevin. To answer Randy-Helis question, yes the design approach can be referred as a 2x8 matrix.

As RandyT pointed out, that's not what was said here (specifically your comments in reply #28 of this thread):

All,
The TOKN KB16 is not implemented in what would be called a traditional keyboard matrix.
There is no row and column scan or search and there are also no ghosting issues. No diodes are needed nor used.
Rather it is a two ground multiplex with high speed interleaved byte latching on a single microcontroller port.
Very effective and very fast for getting port status to the microcontroller and keycodes to your game session.

This was a conscious design decision that required design and test to get it right. Keep trying to angle this as a downfall and you will fail. Your own comments regarding the validity of a matrix implementation that ten billion keyboards across the planet employ followed by open speculation are without merit.

A matrix implementation using diodes will work fine with no ghosting or blocking as stated above.  There is probably a performance hit as opposed to having each input dedicated on the microcontroller, but it shoud be negligible, at least for BYOAC purposes.

95% or more of the ten billion keyboards do not use diodes and will not allow you to randomly even choose 16 keys (using a 16x8) matrix and have them all register, so I don't think you want to use this to validate your product.

NOTE: I am not saying your product doesn't work as advertised without ghosting or blocking, just that most keyboards don't do this.

[KevSteele]

It's nice that we have a variety of encoders to choose from. (Heck, there's even an encoder with a PC watchdog circuit that reboots the computer if it crashes!)

Which one? - Serious Question

The "KeyDog":

http://www.keydog.net/

[NoOne=NBA=]

Mattp,

If you look at the HAMMERING that RandyT took when he released his 49-way interface, you'll get a better idea of the type of people we have around here.

There is a large contigent here that don't care THAT a product works; they want to know HOW it works.

[saint]

This thread has been locked for posterity. Please feel free to continue this subject in a new thread.

--- saint

[saint]

This subject has been resumed in this thread.

--- saint