writing NES controller-to-midi function for MBHP Core (pic)?

[yatagarasu]

Hey guys,

It's been awhile since I have posted, but every year I seem to need this application, and always figure out some hacky way to get around it.

I am wanting to write an app that presses play on my sequencer when I push a button on an NES controller. I am basically going to tap the "Data" out on the NES controller, and wire that into the AIN pin on an MBHP Core module. I figured I would not need an AIN module, since I am just looking to start a song on *any* data piped into the AIN (so no multiplexing required). Would this work? Any ideas for how I should go about writing this application? I could not figure out what functions to call. I think the program needs to run like this:

Start:

Initialize; //vague, sorry, I'm not sure what to do here actually

Set MB module as "master" to all connected devices;

Mainloop:

Poll for any change in AIN;

On change, send start/stop signal to all connected devices;

goto mainloop

end

[TK.]

You could try following example: http://www.ucapps.de/mios_c_send_ain.html

with following code in AIN_NotifyChange()

unsigned int last_pin_value;

void AIN_NotifyChange(unsigned char pin, unsigned int pin_value) __wparam

{

  if( pin == 0 ) {

    if( pin_value >= 700 && last_pin_value < 700 ) {

      // Rising Edge at ca. 70% of 5V (-> 3.5V)

      // Send MIDI Start Event

      MIOS_MIDI_TxBufferPut(0xfa);

    } else if( pin_value < 300 && last_pin_value >= 300 ) {

      // Falling Edge at ca. 30% of 5V (-> 1.5V)

      // Send MIDI Stop Event

      MIOS_MIDI_TxBufferPut(0xfc);

    }


    last_pin_value = pin_value;

  }

}

[/code]


Thats all.


There are also other methods to do this (e.g. using J5 pins as digital inputs), but you asked for the AIN solution, and I want to demonstrate how this can be done.

There is no real disadvantage by using an analog pin for this function - in distance, you get the advantage that you are able to define the hysteresis (as demonstrated above).

So, your idea doesn't match with the standard approach, but it isn't so bad! :)


More details about C programming can be found here:

http://www.ucapps.de/mios8_c.html


Best Regards, Thorsten.

[yatagarasu]

Thanks for this code and info TK! I am going to try implementing this, and then see if I can gradually write something more advanced (like different buttons on the joypad controlling different midi events). And see how far I can get without an AIN/DIN module, and decide if I need one after all.