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+--- Thread: How to add additional buttons? (/showthread.php?tid=4991)
How to add additional buttons? - iron_swan - 07-22-2019
Hi everyone!
Like the post title states, I'd like to add more buttons to my CM3 build. I don't need a fan or analog inputs, so the add-on board seems to be overkill. From studying pictures of the add-on board, it looks like buttons are hooked up like this:
GPIO button GND
This assumes internal pullup resistors in the chip for each GPIO. Can someone confirm this?
Also, am I missing something else, like hardware debouncing?
RE: How to add additional buttons? - Porcinus - 07-22-2019
Hello,
Your wiring is correct, please note that you can use GPIO40-43 but also pads under the Compute Module (35-39 I think).
GPIO 44-45 are used for I2C1.
You will just need to edit the driver config file to add the new inputs : /etc/modprobe.d/mk_arcade_joystick.conf
The pullup registers are set by the driver when it start.
RE: How to add additional buttons? - iron_swan - 07-22-2019
Thank you Porcinus!
RE: How to add additional buttons? - Flavor - 07-27-2019
Hey iron_swan! Did you get it working the way you wanted?
After you wire up buttons like you mentioned (GPIO button GND), then you would want to edit the /etc/modprobe.d/mk_arcade_joystick.conf file to add those GPIO in place of the "-1" entries in the GPIO line.
Is that what you've done?