Yet another plug! This time it’s a proximity capacitive sensor based on the MPR084:
This one has 8 inputs which can be connected to various surfaces to create capacitive touch sensors. There’s also a pin for a piezo sound unit to produce key clicks.
Slightly more elaborate schematic this time, with an extra 8-resistor array for pull-up:
Yet again: connected via I2C, and supports no more than 3.6V as power source. There’s a solder jumper to choose between two I2C addresses, so you can use two of these for a total of 16 inputs on one port (or Plug Shield).
Haven’t tried this chip out yet, but it will be fun to see what it can do – once I get some prototype boards ready.