How to use your Twine breakout boardShort version: The easiest
way to use the Twine breakout board is to hook up a set of
contacts (switch, button, wire) between the IN and GND terminals
(Fig 1). When the contacts are touching, the breakout is
“closed”. When they aren’t, it’s “open”.Longer version (for
nerds): The breakout has three terminals: “3.3V”, “IN”, and
“GND”. 3.3V — power supply from the Twine. This voltage on this
line will vary between 2.3 and 3.3V depending how the Twine is
powered. When running on external power, this will stay constant
at 3.3V. When running on batteries, this voltage will vary
between 2.4-3.0V. The voltage will always be boosted to 3.0V
just before the input is sampled. An internal power circuit
limits current on this line to 50mA. Remember that any power
drawn from this line will directly affect battery life. IN —
input to the Twine. This line is pulled to the Twine’s internal
power rail by a 4.7K resistor. It is highly recommended to only
pull this line low, and never drive it