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. Connect 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. Do not pour water directly on the sensor. The humidity of the water will rust the sensor. The kit can automatically water the vegetable garden, garden, and control the flower pot soil moisture. Type:Automatic Watering System Kit Power Supply:DC 5V Power Bank (Not Included) / 4 x AA Batteries (Not Included) Easy Installation Soil Moisture Sensor Wide Application Note:Due to different production batches, there are differences in appearance, which does not affect usage. Colour:As Shown Material:Plastic+Electronic Components+Metal Package Contents: 1 * relay module 1 * battery box (excluding 4 x AA batteries) 1 * soil moisture detection module 1 * sensor module 1 * water pump 1 * USB power cable 1 * hose 1 set * wire ( wire color is random, no specification is accepted) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.