FicBox CTYRZCH HX1838 Infrared Remote Control Module IR Receiver Module DIY Kit HX1838 for Arduino Raspberry Pi Sensor uses HX1838, high sensitivity Operating voltage 5V Digital output VCC external 3.3V-5V voltage (can be directly connected with the a 5v microcontroller and 3.3v microcontroller) GND external GND IN an external microcontroller I / O port, I / O port has been designed 10K pull-up resistor