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Keyboard encoder

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Fozzy The Bear:

OK start by disconnecting the Mars Mech from the credit board......  Then hit the credit button on the credit board.... What happens??  Is the encoder still showing about 12 keys pressed??

I'm not sure why it would be showing 12 keys pressed if the connection between the credit board and the encoder is only on two wires, connected to Ground and Coin Up on the key encoder.

If you haven't made 12 connections to the key encoder it's a bit of a mystery why it's showing 12 keys pressed. You might want to add a dropping resistor into the line there to pull the voltage down from 12V to 5V. Stick a meter on it and figure out what you need to limit the current. If it seems to the encoder to be sending coin up all the time then that 0.06V might be enough to be triggering the encoder input. The resistor should cure that one by pulling that voltage right down to next to nothing.

This sounds like more of a problem with the encoder than the connections made. I can dig out the manuals for mars mechs if you need them. Although if it needs a re-program it'll be a bit of a bugger without the right kit to do it.

Do you have a manual for the credit board?? Without that it's going to be impossible to tell if the dip switches are set correctly for the price of play that you want to set and the type of output you want. That's a Kent, credit board... I might be able to dig out a manual for it if I can figure out exactly which one it is. The trouble with them is that they're all different in the switch settings.

To be honest, that GS Arcade box is the suspect here..... They're not the best choice of encoder on the planet. They have ghosting and key blocking problems. You say it coins up during a game... do you mean without an intentional coin up signal?? that could be a result of key ghosting where when you hit combinations of buttons others get triggered at the same time, due to the poor key matrix based encoder.

Best Regards,
Julian (Fozzy The Bear)


RandyT:

Again, Fozzy is right on the money. 

Those encoders are junk, unless you are building a small panel with very few controls.   They are falsely advertised.  I know this because I wasted money buying one when I suspected these were inferior items being pushed onto unsuspecting members of the community with improper specifications.  It turned out that I was correct.  These are nothing more than a standard, matrixed keyboard chip.  A pre-hacked keyboard, if you will.  Severe blocking and ghosting problems, even though the description specifically, and deceitfully, states they don't have these issues.

The seller is still selling them on ebay with the fraudulent description, even though I informed him of the problems with them. 

I posted on these in the past, but I'm bringing it up again to hopefully help spare someone the expense and aggravation of these things.

As for why this is making 12 keys pressed with one....  Because these operate on a matrix, there is no common ground.  To get a keypress out of a matrix, the encoder will internally change the state of a row/column and then look for a state change of a member of another row/column to see if they are connected (through a switch).  If you hook the 0v (ground) to a row or column of a matrix, it has the effect of overriding the internal function that does that, thus indicating that every one of the keys on that row/column is activated.  This description is a little simplistic, but I'm sure it what you are experiencing.

The short of it is that the coin board is incompatible with that "encoder".  None of the input lines can be grounded, only connected to other input lines on the board.  Your coin mech seems to require a ground on one side.  The only workaround I can think of would be to use an analog switching chip (or tiny relay), and possibly an inverter between the coin mech and the "encoder" to connect two lines of the encoder together when the coin mech sends a pulse.  But that won't help the other issues you're sure to experience with that "encoder".

RandyT

Orclord:


--- Quote from: Fozzy The Bear on January 26, 2008, 08:28:20 am ---
kit to do it.

Do you have a manual for the credit board?? Without that it's going to be impossible to tell if the dip switches are set correctly for the price of play that you want to set and the type of output you want.
Best Regards,
Julian (Fozzy The Bear)


--- End quote ---

In the link he provides there is a tech spec sheet.


http://www.dmkent.co.uk/pdf/coin_dt.pdf

*Edit*

---Cleveland steamer--- just read the "Old version" bit....

Must stop drinking.....

Tomorrow maybe..



RandyT:


According to the manual, the relay output is a factory installed option.  So, as Fozzy stated, without knowing the specifics of the board being used, it's impossible to know if its set up properly, or even capable of being set-up that way.  The board picture shown has a big empty spot where the relay would be, so if it looks like that, the only option would be to add one somehow.

RandyT

DiGi:

Thanks for the help so far looks like it may be a no go then but this is what I'm getting at the moment. Its the same with or without the credit mech connected.

This is what happens with the credit button pressed

If i hold the credit button all the keys flash and cycle but CTRL button bottom left stays on even after i stop holding the  credit button , until i press the button that CTRL is assigned to which is player 1 button 2.

I then noticed that if i hold the Cred wire onto one of the crimps it shows the same as above without the ground wire connected while if on the other crimp it shows as clear even with the ground connected until the credit button is pressed.

I took a photo of my board



It has PCB 84275 by the chip with the sticker and the dip switches i left as they were originally but i presumed they used a similar credit and bonus plan to the one in the link above which is on there as a pdf file,  I have no other information i did contact DM Kent for the price of a new one but they told me there new ones may be incompatible with the MS111TS stating

"The current COIN+DT boards are only compatible with coin mechs where the signal common is referenced to 0V (which covers all current production by all known manufacturers). 
If you have technical literature on the coin mech. then check that the electrical interface description states that the "signal common" (or similar wording) can be grounded, 0V, low or similar wording.  Alternatively it might state that the interface is bipolar or "dual voltage" or similar."

Don't know if this helps there was a bit more info in the email which i could post but i don`t want to waste peoples time i am able to do a few things but Ive forgotton most of my electrical training i had in my teens.

Edit:


--- Quote --- You say it coins up during a game... do you mean without an intentional coin up signal?? that could be a result of key ghosting where when you hit combinations of buttons others get triggered at the same time, due to the poor key matrix based encoder.
--- End quote ---
The coin when inserted to the mech trigers the credits correcly  but because of all the other key triggering i get the test screen and the volume options, the encoder works fine if im using a microswitch  ive had virtual encoder up and tried as many 10 inputs and they seem to be fine.

Ive just tried pressing the button  which is assigned to the letter F this now highlights 14 more buttons but dfferent to the ones in the picture  but only when the credit board is wired else it works fine :hissy:

Thanks again

DiGi



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