I'm looking at the Spark Fun Big Dome Push button. The spec on the page (and other places selling it) says that the LED is 12VDC. Does this mean that I need 12V as a minimum? Am I not able to just swap out the LED for one of my own (much lower voltage) if I dismantle it? I can't seem to find a datasheet for it.
Ultimately I want to have it connected to my machine via USB – which is why I can't provide it with 12V. My first thought at accomplishing this was to use an ATTiny85 I have connected via a USB to Serial breakout (or one of those USBs with an FTDI chip in them).
Any help would be much appreciated. Or alternately if my method to read the button's input is roundabout please let me know as I don't have an EE background!
Best Answer
The LED and switch are separate.
The LED says it needs 12 V, this might be because they've connected several LEDs in series, or used a large resistor. No way to find out except to ask them, or buy one and look. If it is multiple LEDs you might be able to cut some tracks and put them in parallel, so they work at 5V
The switch is a 3 contact microswitch, so will be very easy to read from a small microcontroller. Your plan is probably the neatest and quickest way to get a switch to talk to USB.