Title: pcb/carbon buttons, looking for sugestions
Post by: bveina on April 17, 2017, 06:40:59 pm
Post by: bveina on April 17, 2017, 06:40:59 pm
I'm looking to see if anyone around here has some experience with pcb carbon buttons.
background:
bought a cheap n64 usb controller, doesn't really do the business.
has an analog stick, doesnt report analog values
dpad and analog stick are tied together in software (???)
the easy path is go buy another one. but as an experiment i thought i would design a new board with a atmega32u4. as you can see from the attachment, the button contacts have a carbon coating. does anyone have any experience and could indicate if i could get away with just a hasl finish, and perhaps a denser set of fingers?
i can always just try it and see but thought i might reach out for tips first.
background:
bought a cheap n64 usb controller, doesn't really do the business.
has an analog stick, doesnt report analog values
dpad and analog stick are tied together in software (???)
the easy path is go buy another one. but as an experiment i thought i would design a new board with a atmega32u4. as you can see from the attachment, the button contacts have a carbon coating. does anyone have any experience and could indicate if i could get away with just a hasl finish, and perhaps a denser set of fingers?
i can always just try it and see but thought i might reach out for tips first.
Title: Re: pcb/carbon buttons, looking for sugestions
Post by: Sjaak on April 18, 2017, 09:56:21 am
Post by: Sjaak on April 18, 2017, 09:56:21 am
If seen those with just ENIG coating. I suspect the HASL surface will oxidizes and make it difficult to work reliable over time.
Title: Re: pcb/carbon buttons, looking for sugestions
Post by: bveina on April 19, 2017, 02:58:36 pm
Post by: bveina on April 19, 2017, 02:58:36 pm
that's just about the same conclusion i've come too as well.
its also been suggested that various products (search the internet for "rubber keypad repair kit") are designed to put new carbon on traces.
im looking into fabbing a board with a few test contacts, enig, then manually tin one, and observe the voltage divider effect over time. then ill know.
the overall project took a bit of a dive when i measured the width of the board at 130mm. it would be a tad more expensive than i want.
its also been suggested that various products (search the internet for "rubber keypad repair kit") are designed to put new carbon on traces.
im looking into fabbing a board with a few test contacts, enig, then manually tin one, and observe the voltage divider effect over time. then ill know.
the overall project took a bit of a dive when i measured the width of the board at 130mm. it would be a tad more expensive than i want.