This tutorial will guide you through the process of building a tachometer around an Arduino ... the reading. Wiring and driving the LCD ends up being the hardest part. An IR transmitter/receiver ...

The video demonstrates how to wire up a Passive Infrared Sensor (PIR) using 4-core security cables. All Gallagher inputs are balanced 4-state inputs and must have two 4k7 resistors wired at the device ...

You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to ...