Neotrellis M4 phantom keypresses

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Joshyj
 
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Neotrellis M4 phantom keypresses

Post by Joshyj »

Hi,

when I hold down the third button down on the left on my neotrellis m4, I get phantom keypress from other keys in that row. It's reproducible. My code deals with all keypresses the same, and it's the only button that it happens with.

I'm trying to write software fix but it would be great if there was another way to fix it?

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mikeysklar
 
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Re: Neotrellis M4 phantom keypresses

Post by mikeysklar »

This FAQ entry appears to address the whole row activation scenario.
When I press a button on the NeoTrellis a whole row is activated?

It's possible to accidentally "press" a column of four buttons even when you intend to only press one. This can happen when you press a button at an angle other than straight down on top of the button pad. The elastomer conductive part touches the NeoPixel ground pin against the column which makes the chip think the whole row/column is pressed. It only happens on some buttons and some angles, and is not common

It's not harmful, and there's a few ways to avoid it:

Press straight down on buttons not at an angle
Cut a thicker top panel from wood/plastic/3D printing so that the buttons cannot be pressed at an angle
Read buttons via the https://github.com/adafruit/Adafruit_NeoTrellisM4 library which will do a software filtering to remove the duplicate button presses
https://learn.adafruit.com/adafruit-neo ... aq-3011817

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Joshyj
 
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Re: Neotrellis M4 phantom keypresses

Post by Joshyj »

Thank you kindly for your answer.

I have written my own software solution at the moment meaning only one key can be pressed at the same time.

It appears to be working.

Regards,

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