Android Arts
Keyboard
I'm not sure what the formal term for this thing is. Maybe Resistor Ladder or Voltage divider. It's just a series of 220Ω resistors, so pushing button 3 connects 3*220Ω to the OUT rail. There's also a socket for a "base" resistor (pulldown?) which is 1MΩ here.
I used SMD 2-leg buttons because the ones with legs fit poorly into perfboard. I held them into place while soldering by using greenstuff (a dot underneath).
This type of device is useful when conserving pins on an MCU (1 analog pin instead of 8 digital). By reading the resistance, the MCU can figure out which button was pressed. Because the current takes the path of least resistance, only one button can be read, but there might be ways around this...?
Shrink tubes on helping hands makes their bite softer. I need to get some proper tentacle arms though.
Keyboard
I'm not sure what the formal term for this thing is. Maybe Resistor Ladder or Voltage divider. It's just a series of 220Ω resistors, so pushing button 3 connects 3*220Ω to the OUT rail. There's also a socket for a "base" resistor (pulldown?) which is 1MΩ here.
I used SMD 2-leg buttons because the ones with legs fit poorly into perfboard. I held them into place while soldering by using greenstuff (a dot underneath).
This type of device is useful when conserving pins on an MCU (1 analog pin instead of 8 digital). By reading the resistance, the MCU can figure out which button was pressed. Because the current takes the path of least resistance, only one button can be read, but there might be ways around this...?
Shrink tubes on helping hands makes their bite softer. I need to get some proper tentacle arms though.