74HC138 (3 to 8 Line Decoder- Demultiplexer) Infrared Object Detection An IR blocking filter

An IR blocking filter

SparkFun 16 Output I/O Expander Breakout - SX1509 is a 16-channel GPIO expander with an I2C interface – that means with just two wires

Power supply: external

but one at a low altitude

74HC138 (3 to 8 Line Decoder- Demultiplexer) Infrared Object Detection An IR blocking filterIntroduction : The 74HC138 decodes three binary weighted address inputs (A0, A1 and A2) toeight mutually exclusive outputs (Y0 to Y7). The device features three enable inputs (E1, E2 andE3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enablefunction allows easy parallel expansion to a 1 of 32 (5 to 32 lines) decoder with just four '138 ICsand one inverter. 74HC138 can be used as an eight output demultiplexer by