This is a 5V 4-channel relay interface board, and each channel needs a 15-20mA driver current. This 4-way relay module can be used to control various appliances and equipment with large current. This four-channel relay module is equipped with high-current relays that work under AC250V 10A or DC30V 10A. 5 volts relay driver module has a standard interface that can be controlled directly by the microcontroller. This relay module board allows a wide range of microcontrollers such as Arduino, AVR, PIC, ARM with digital outputs to control larger loads and devices like AC or DC Motors, electromagnets, solenoids, and incandescent light bulbs.

The Obstacle Detector sensor module is perfectly adaptable to the environment light, IR Object Avoidance Sensor has a pair of infrared transmitting and receiving tubes; transmitting tube emits infrared in a certain frequency, when detecting direction meets with obstacles(reflecting surface), reflected infrared will be received by the receiving tube; after the comparator circuit processing, the green indicator will light up, at the same time signal output interface to output digital signal(1 low-level signal). Users can adjust the detection distance through the potentiometer knob, effective distance range 2~30cm and working voltage is 3.3V to 5V. The Obstacle Avoidance module LM393 can be widely used in robot obstacle avoidance, obstacle avoidance car, line count, black and white line tracking, and so on many occasions.