The updated 2019 edition BLTouch Smart V3.1 caters to many minor problems of previous versions, while adding extra features for enhanced accuracy.
The 3D Gesture Sensor from DFRobot is a clever little board that can sense hand-gestures in four directions, as well as rotational gestures.
Pulse Sensor is a plug-and-play heart-rate sensor for Arduino. It can be used by students, artists, makers, and developers who want to integrate live heart-rate data into their projects.
Tiny touch sensitive button module for replacing traditional mechanical touch switches. Uses the TTP223 touch sensor IC