Hi,
I have a question about the Adding arcade buttons tutorial.
If I read it well, the buttons are connected to 1 GPIO et to the GND, correct ?
In every other tutorials, how-to... buttons needs to be connected to the 3.3V (with 1/2 resistors), to GPIO and to GND.. How the pi can read an "unplugged" button ?
Thanks for the help
Retrogaming with RPI - Buttons
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- egutting
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Re: Retrogaming with RPI - Buttons
I'm not completely sure (pburgess probably can give you a better answer), but I would think that the Pi may be looking for a falling interrupt and attaching an action to it. Kind of similar to this blog post:
http://www.adafruit.com/blog/2013/03/29 ... io-part-3/
http://www.adafruit.com/blog/2013/03/29 ... io-part-3/
- adafruit_support_mike
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Re: Retrogaming with RPI - Buttons
The RasPi's GPIO pins have built-in pull-up resistors. If you tell the microprocessor to use the pull-ups, you don't need an external resistor.
- Adisma
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Re: Retrogaming with RPI - Buttons
Thanks.
But in this tuto buttons are connected to 3.3v.
In adafruit arcade tuto they're only connected to gpio and ground..
But in this tuto buttons are connected to 3.3v.
In adafruit arcade tuto they're only connected to gpio and ground..
- adafruit_support_mike
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Re: Retrogaming with RPI - Buttons
Like I said: the RasPi's GPIO pins have built-in pull-up resistors.
When you enable the pull-up, the chip makes the connection between the GPIO pin and 3.3v internally.
When you enable the pull-up, the chip makes the connection between the GPIO pin and 3.3v internally.
- Adisma
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Re: Retrogaming with RPI - Buttons
Great ! Thanks :)
Ok, they are ^^Do you know if the "retrogame" utility available in the tuto enables the pull-up resistor ? Or, is it a way to enable them by default ?
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