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analog pot to analog pot adapter. An EE question.
Ed_McCarron:
In hindsight, that also assumes you're using the pot as a simple resistance, and not as a voltage divider. No clue how that would work.
If the input to the game is just a voltage reference picked off the wiper of a pot wired as a voltage divider (ie, 0v on one side, 5v on the other...), does the actual resistance matter?
Need more input.
Howard_Casto:
--- Quote from: Ed_McCarron on June 01, 2011, 11:00:53 pm ---In hindsight, that also assumes you're using the pot as a simple resistance, and not as a voltage divider. No clue how that would work.
If the input to the game is just a voltage reference picked off the wiper of a pot wired as a voltage divider (ie, 0v on one side, 5v on the other...), does the actual resistance matter?
Need more input.
--- End quote ---
What he said. And I can unfortuantely assume for you (judging by the mame drivers) that hangon doesn't have truely analog inputs and does use the post as a voltage divider. I think you are going to just have to hook some stuff up and play with it.
If I remember correctly hangon has a fairly good test menu.
danny_galaga:
How weird is this pot you're talking about? Surely there must be SOMETHING in the same range that you could jury rig? Digikey have thousands of types for instance. Might take a while to go through, but if you find the right one, you're set...
SavannahLion:
Really, it's just a thought I have. Those were just examples I gave.
My Hang-On is currently blind so replacing the pots this early is pointless. Until a new monitor that doesn't blow up is sourced, all I can do is mechanical and cosmetic work. Electrical work is delayed. :(
The 2600 uses a capacitor then drains it at regular intervals to determine the value of the pot. I can't figure out what I did with the video adapter for that one.??? No matter, it's in pieces now.
MonMotha:
What you have to do here depends quite a bit on how the pot is read. In some cases, the resistance of the pot doesn't matter much, only wiper position. In other cases, the resistance of the pot is of primary consideration. Adapting one end-to-end resistance to another is a process that's difficult to do without knowing much about what it's hooked up to.
FYI, the A/D process you're referring to on the 2600 is called a "ramp compare" ADC. They're cheap but not particularly accurate. They're good enough for a video game, though. With most of these designs, the end-to-end resistance does matter.
On a reasonably Hi-Z input ADC (like a SAR or FLASH), the end-to-end resistance is in general not a big deal if the pot is used as a voltage divider. Anything within an order of magnitude is likely to work reasonably well.
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