I recently had to build an infrared close proximity sensor that could tell if something was ... IRED1 is modulated by connecting its anode (A) to ~38kHz signal yielded by D9 of the Arduino Uno (TP1) ...

The digital signal output to be detected (usually marked as DO in the module) is applied to D2 input of the Arduino. Analog output (marked as AO) from the module is not used here. Sensor-head of the ...

There are many different sensors that can be used to detect motion in a given environment. Passive InfraRed (PIR ... if you send an RF signal at a given frequency to a moving target, the reflected ...