Intergrated Volume and Brightness Dpad question??

[zenloc]

So I have read that you can press a buttons in this case start and use the dpad/Cbuttons to control the brightnes/volume.

See this diagram.


My question is. Won't you also activate the dpad(normal in game) once you press and hold the start button. I mean when you press the dpad buttons they still are making a connection. So that would mean while you are changing your brightness/volume you would also be fiddeling about with the dpad???

Need to clarify this so I can use to in my portable.

Another question... How can I make a switch to make the analog into a dpad but still keeping the analog.
So normally I use the analog then when I hold or switch a button it will stop working as analog and turn into the dpad.

Any idea's?

[Axaj]

For your first question, you'd just need two NAND gates to fix that, and since 2 NANDs = 1 AND, you can just use a NAND chip for the whole thing (I think).

[zenloc]

Their was a discussion in sifus n64 thread, but it's still unclear how it exactly works. Nand or no nand once you press dpad button up it still sees it. Even when I hold start.... Or am I missing something...

Anybody know something about this??

[evilteddy]

That circuit above ouputs through the AND gates when the start button and a Dpad direction is pressed however there is no circuitry to disconnect the Dpad while you're doing it. It really isn't an issue because most of the time pressing the Dpad in game will have no effect while pressing the start button will just pause it while you change the volume.

Shouldn't you be using ANDs instead of NANDs. Just looking at a truth table shows that a NAND gate will be high when both inputs are low which is obviously not wanted here.

Evilteddy

[zenloc]

I'm trying to understand how this works.... don't have much experience in this field.

Sifuf used this schematic to control the volume and brightness with the dpad while holding the start button.

I understand what the and gates do but why do I need the two other components (not-4069 and the npn-2n3904)???

And wht's the difference with the schematic in the frist post and this one. The other one uses a nor gate instead of a and gate what's the difference??

This is the last thing I need to do on my handheld n64mini and then I'm done... I'm using the c buttons though instead of a dpad.

Any clarification would be much appreciated