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Topic: NEED HELP ASAP - FINAL YEAR PROJECT DUE ! MAME (Read 1 time) previous topic - next topic

malt3z

hey guys ive been making a MAME cabinet for the past few months. Originally in order to use microswitch pushbuttons in order to replicate a keyboards buttons presses, a keywiz PCB was used.. but didnt work. I went to Jaycar electronics and asked for their advice, and was told that a arduino mega PCB will do the trick. I have a few questions
- i have the buttons all wired to pins, and pins placed in said slots.. but in order to power the microswitches, where should i get the power from? i daisy chained all the buttons and connected one end to the 5v and the other to the GND, but the LED's on the board just turn off, which im guessing means i am shorting the circut. How should this be correctly wired?

- the coding side of this is very.. very confusing to me. Is someone able to create me a code that will allow me to have 16 buttons and 8 joystick switches giving keyboard commands (z x UP DOWN etc.)?

i know its a lot to ask for but i now have less than a week to complete this and its make or break as it contributes to 80% of my mark for the year..

also i didnt know where to post this as im new to the forums, if there is an admin that notices this and how the power to, please move this to its appropriate forum.

THANKS IN ADVANCE GUYS!

jackrae

1 provide the circuit diagram of what you've already built
2 provide the code that you've already written

then someone might just try to guide you so that YOU can do what's necessary to avoid being tagged as a cheat.

MichaelMeissner

I suspect you need to start at the beginning.  Follow the tutorial for ReadDigitalSerial (http://arduino.cc/en/Tutorial/DigitalReadSerial) to get 1 button working.  Then add 2, 3, etc.  Don't immediately try doing all 16 at once.

As a hint, you don't want to daisy chain all of the buttons connected to both 5v and ground.  Instead you want to connect all of the buttons to ground each with their own resistor, and then connect each button to a separate digital pin on the Mega.

Similarly for AnalogReadSerial (http://arduino.cc/en/Tutorial/AnalogReadSerial) to read from the joysticks.

I suspect you are going to be burning a lot of the midnight oil on this project.

James C4S


a keywiz PCB was used.. but didnt work.

Define "didn't work"? 

You went from a solution designed specifically for what you are doing (keywiz) to a general purpose device (Arduino).  That seems like a strange change.
Capacitor Expert By Day, Enginerd by night.  ||  Personal Blog: www.baldengineer.com  || Electronics Tutorials for Beginners:  www.addohms.com

justjed


I suspect you need to start at the beginning.  Follow the tutorial for ReadDigitalSerial (http://arduino.cc/en/Tutorial/DigitalReadSerial) to get 1 button working.  Then add 2, 3, etc.  Don't immediately try doing all 16 at once.


There's also debouncing, which is probably important for an arcade system. Well, I'm assuming arcade, because the MAME I know about is the Multi Aracade Machine Emulator. Really cool thing for playing Galaga on my Linux box. :)
... it is poor civic hygiene to install technologies that could someday
facilitate a police state. -- Bruce Schneier

MichaelMeissner


There's also debouncing, which is probably important for an arcade system. Well, I'm assuming arcade, because the MAME I know about is the Multi Aracade Machine Emulator. Really cool thing for playing Galaga on my Linux box. :)

Yes, once the OP can read digital and analog signals, then he/she needs to think about debounce (particularly for the joysticks), but it sounded like he/she was at a more basic level.  Of course the problem with doing debounce for 8 analog joysticks, is you don't want to do read, dobounce, read serially on each value, but instead you want do all of the initial reads, then the delay, and then the 2nd reads.  And when you are dealing with 24 buttons, you need to start thinking of using things like arrays.

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