Question Combining screen controls with standard buttons

[MRKane]

Hello all!

So I'm once again under the hood of my little Wii U PS2 and found myself wondering if I could make more of a mess of it by trying to use the buttons of the unit itself for controlling the screen. The HDMI screen I've got seems to be triggerable using a standard tact and it looks pretty straight forward as far as the lines go but I've been left wondering what the best way to do this would be.

So what I'm imagining is probably using a multiplexer or similar to shut off the lines back to the screen driver board as naturally the return is ground, but given that the time between me ordering this and the components arriving is about two months for me I could really do with a nudge in the direction of what works and what doesn't

 

[hazardousracerx]

You could use a Teensy LC to look at button combos and output to the screen driver board the desired action. I'm not familiar with all PS2 games, but there must be a common button combo that none of them use in game that could "activate" the screen controls.

Use the Teensy to activate a transistor which will switch voltage paths between screen driver and PS2 depending on the mode. Or, actually implement a physical switch that will do the same thing still using the teensy or some other microcontroller.

Thanks for the spur on the idea btw. I might just implement this in my PS2Go to save on button holes and mounting in the case.

Edit:
I don't think a micro controller would be absolutely necessary if you just use a switch to control the button power source depending on the voltage going through the screen driver buttons.

Edit 2: I may be wrong about the first edit the more I think about it. Since everything shares a common ground you would need a switch for each “double” button. Micro controller or similar is still the way to go.

 

[MRKane]

Man Teensys are great aren't they! I've kept tinkering with my last PS2 portable and trying to improve it, of course this rabbit-hole of "use the buttons here" also leads to thoughts of replacing the audio amp I've got with the one on the BOM and using the face buttons for controlling the volume also etc. that leads onto "I've got no room for a speaker port so could I fit a blue-tooth board" and other such ideas lol

 

[hazardousracerx]

Bluetooth board is a good theoretical idea, but most of them introduce an audio lag because of the processing required . Makes for a bad gaming/video experience to have audio .5 sec (or more) out of sync. If you can find the right one it might be ok though. Every one I have used has the lag.

 

[MRKane]

I've experienced that too. Real shame really as it could be something fantastic.

 

[Stitches]

Gman did something like this with one of his DMG WiiBoys where holding volume down for a second triggered the buetooth sync button. IIRC Aurelio helped him do it, so perhaps they could provide some insight on if it's practical. Otherwise, JacksonS did some good multiplexing with his 3 controllers 1 portable project. He had documentation for it somewhere.

 

[MRKane]

Thanks for the heads up! I figured it'd use a multiplexer or two to enable/disable the paths. I might have a look for that thread, thanks a heap!

 

[Matthew]

It's possible to use the ps2+ for triggering things. There are a few unused gpio on the board and the coding should be really simple. I'm happy to help if needed.

 

[MRKane]

That's a really good idea! I'll have to have more of a look at the code there - it'd sure get around the need for having as many switches and I guess could also be used to disable input into the PS2 while working with other settings.

I will say that this is getting away from my original plan of "modify my existing unit" and looks more and more like making another PS2 portable. What a horrible thing that'd be! lol

Also if you remember I mentioned that I'd ordered the chips for it? They're still not here.

 

[MRKane]

To add to this story and keep everything up to speed. I figured out how the button presses were handled on the screen, and it turns out they're the same as the other one I've got here. There's a 3.3V line leading into the board and a collection of voltage splitters servicing each button, with a single line carrying the information back to the board (Lets call it "DAT"). Each button has a different voltage and that's about it.

I guess this means that I only need to gate two lines (3.3v and DAT, and have the PS2+ ignore different voltages coming in while it's in "screen mode".

Thus my question is: Can I do this, or will it cause issues with the little PIC chip? One of the buttons is also GND which I'd assume is the common for the PS2+

 

[Gman]

I used an i2c dac for screen controls in the 2dc.

 

[MRKane]

Frankly that's genus! See this is what happens if you've got no actual learning in something - you end up creating heaps of voltage splitters to test things.

I'll investigate a i2c DAC that has enough channels (7 or 8 by the looks of the screens) to handle any of the screens' inputs I have and then do the two month wait thing for it to show up.

Thanks so much for the help Gman!

 

[MRKane]

Ok, I'm going to have to ask which DAC you ended up using as they all seem to be pretty expensive. My base logic is: Could I do this cheaper with an Arduino Nano. Price really is a problem for me sadly.

 

[Gman]

Ok, I'm going to have to ask which DAC you ended up using as they all seem to be pretty expensive. My base logic is: Could I do this cheaper with an Arduino Nano. Price really is a problem for me sadly.

https://www.digikey.com/product-det.../MCP4706A1T-E-CH/MCP4706A1T-E-CHCT-ND/7065580

You'll still need an arduino or microcontroller to interface with it.

 

[MRKane]

Right! Thanks for the leg-up here, looks like I've got some learning ahead for me