Test the relay module: connect the relay module VCC to 5V, GND to ground, IN to GND, the relay jumps, and when IN is suspended, the relay recovers, so you can hear the relay "" sound repeatedly. Test the soil moisture sensor module: connect the fork probe and transmitter module with two lines, the transmitter module VCC is connected to 5V, GND is grounded, just after power-on, the red power light is always on, green (blue) color indication The lamp flashes faintly once; the fork probe is directly inserted into the water, and the green (blue) light is on. Through adjusting the potentiometer to control the soil humidity threshold,can automatic watering the vegetable garden, garden, control the flower pot soil moisture. Connect the of the pump to 5V, the black line is grounded, the pump works, pay attention to the test for 1 second, and it is not allowed to work in the air for a long time. Easy assemble, make your life more automated, particularly suitable for people who travel frequently!, Manufacturer: Jnchdghwa