David Buchanan
Concept: wireless keyboard, but each key is an independent unit, powered inductively (same idea as "wireless LEDs")
Dec 19, 2022 at 2:37pmWeb
Show threadTerry IpDec 19, 2022
@retr0id with piezoelectric ceramics?
Show threadDavid BuchananDec 19, 2022
@terryip I haven't figured out how the response would work exactly yet, but I'm thinking some kind of simple RF transmitter that (if the key is pressed) "reflects" back a signal at a specific frequency, to be detected by a base station.
Show threadAndrew TergisDec 19, 2022
@retr0id @terryip This probably isn't practical for your solution (>$$$!) but if you're not familiar with these energy harvesting switches they're a real neat product concept: https://www.mouser.com/new/zf-electronics/cherry-energy-harvesting-switches/
Show threadAndrew TergisDec 19, 2022
@retr0id @terryip You're almost describing something similar to RFID/NFC (base-station actively transmitting RF, peripheral modulates the RF field), and I think a keyboard could be low-powered enough to energy harvest off the active field. Some of NXP's more advanced NFC chipsets could do this for you, and you could use it like a communications pipe / simple shared memory buffer.
Show threadIgnas KielaDec 22, 2022
@[email protected] @terryip Hmm, if we had a grid of magnets with coils around them, and each key-unit had a magnet and a coil connected to a key that's normally open, I think the base-unit could detect key presses purely by how power usage of individual coils would spike.
Show threadrobrykDec 19, 2022
@retr0id What is powered in the key? (a light/a display/...?)
Show threadDavid BuchananDec 19, 2022
@robryk A switch.
Show threadrobrykDec 19, 2022
@retr0id I'm confused. I expected that you wanted to power something in the part of the key that moves. But you don't need any powered part of the switch there: if nothing else, you can have a reed switch/Hall sensor under it and a magnet inside.
Show threadrobrykDec 19, 2022
@retr0id Aah, you want to power the keys from a nontrivial distance?
Show threadDavid BuchananDec 19, 2022
@robryk No distance required.
Show threadrobrykDec 19, 2022
@retr0id Then how does this differ from having a bunch of reed switches underneath that detect the status of the keys? (I'm probably missing some obvious part of the description.)
Show threadBenDec 19, 2022
@retr0id david what the fuck
Show threadDavid BuchananDec 19, 2022
@teraben You've never wanted to rearrange your keyboard layout on the fly?
Show threadBenDec 19, 2022
@retr0id I already have to remember 3 different layouts have mercy
Show threadSaagar JhaDec 20, 2022
@retr0id @teraben We had that and it was called a “software keyboard”. Benefits include not having 50-odd pieces to arrange
Show threadEli the BeardedDec 19, 2022
@retr0id Why not figure out how to use some piezoelectric force to broadcast a signal on click?