74HC139 (Dual 2 to 4 Line Decoder) 74174 the module includes ultrasonic transmitter

the module includes ultrasonic transmitter

LM358 (Op-Amp) is a dual op-amp IC integrated with two op-amps powered by a common power supply

The PIR sensor itself has two slots in it

Mega 2560 is an update to the earlier Arduino Mega board

74HC139 (Dual 2 to 4 Line Decoder) 74174 the module includes ultrasonic transmitterIntroduction : 74HC139 decodes two binary weighted address inputs (nA0, nA1) to four mutuallyexclusive outputs (nY0 to nY3). Each decoder features an enable input (nE). When nE is HIGH alloutputs are forced HIGH. The enable input can be used as the data input for a 1 to 4 demultiplexerapplication. Inputs include clamp diodes. This enables the use of current limiting resistors tointerface inputs to voltages in excess of VCC. Features : Propagation