Vitor Oliveira

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9 years, 2 months ago.

Change CCD for an analog plunger?

Hello Mike,

I'd like to thank you for all your excellent work with PinScape!

Through my already long research on how to make a virtual pinball machine, I saw the idea of using an analog plunger in http://www.klomp.de/index.php/virtueller-flipper-vpin-selber-bauen/homemade-virtual-pinball-cabinet-vpin.

Do you think that we can replace, or even add a new option to the software, to use a normal potentiometer to replace the CCD?

What do you think?

Thanks and regards,

Vitor

Question relating to:

Last updated: 15 Feb 2016
An input/output controller for virtual pinball machines, with plunger position tracking, accelerometer-based nudge sensing, button input encoding, and feedback device control.

Sorry Mike about making the same question! You already answer to it before. I will try to take a look into it myself.

posted by Vitor Oliveira 20 Feb 2015

1 Answer

Mike R
9 years, 2 months ago.

Glad you found the other question/answer - in case anyone else is looking, here's the link:

http://developer.mbed.org/questions/4566/Plunger/

Short answer: it should be doable at a technical level, but I'm not too fond of the idea of using a potentiometer as the sensor because I expect it'll suffer from calibration drift. One of the things that motivated me to build this in the first place was that the available commercial plunger kits that are based on IR proximity sensors have trouble staying calibrated. A good potentiometer is probably somewhat better than an IR sensor in terms of precision and stability, but I'll point out that the old analog joysticks that were based on potentiometers often gave gamers fits because their zero point would drift.

Hello Mike,

Thanks for your answer.

Probably I am not seeing the complete picture but since we are measuring a tension when the potentiometer is plugged, we can also record the values after calibration. If we are able to know when there is no activity, for instance, when not playing, we can remeasure the steady state value of the potentiometer and tehen, if different from the calibration value, add some kind of compensation in the software. What do you think?

My regards,

Vitor

posted by Vitor Oliveira 20 Feb 2015

That approach would probably help - the software already does the same thing with the accelerometer to keep it zeroed, and it works well for that. Other people have used potentiometers for plunger sensing, and I think there are some linear pots available that are the right size for the job, so it could definitely be worth a try. Certainly an inexpensive solution if you can get enough precision out of it.

posted by Mike R 20 Feb 2015