HALJIA 5PCS RCWL-0516 Microwave Radar Motion Sensor Module Body Induction Switch Module High Sensitivity Long Sensing Distance Wide Sensing Angle for Detecting Moving Objects Compatible with Arduino

I tested all five of them on receipt because of the poor reviews from others. They all worked fine out of the packet. Much more consistent performance than the pir modules I’ve used previously and lower power consumption. Cheaper too.

Good value for money and trouble free issues.

Received these today, and have found out some interesting things by experimentation. They are very sensitive flexible units that can be configured by adding a number of components to the breakout board.It is very important that the unit is not near any metallic object when in use. I thought mine were broken when I first started to use them, but in fact the problem was caused by using them on a solderless breadboard, putting them on a 30cm ribbon cable away from the breadboard solved my problems.There is a large pad marked CDS that will take a photo resistor to disable output when lit.On the back of the board there are surface mount pads for:-C-TM capacitor to lengthen the trigger time.RC-CDS resistor, Change light threshold if a photo resistor is attached to the front.R-GN resistor, Shorten the detection range. 1Mohm reduces range from 7m to 5m.The unit can be used either with or without a support MCU.

I found that the device picks up interference from connected Esp32 when used to trigger gpio which keeps output high, rendering them useless for picking up movement. I could not figure out whether it was power line induced or radiation from the Esp32 radios, tried power filters and shielding the two devices from each other, to no avail.

Works fine

All 5 of them only detect movement no more than 3cm away. Tried 5V and 12V Vin, all the same.

The product is easy to use and works fine. I just think it's a shame that the level at which it triggers is built-in and can't be changed so you just get a single binary signal. I would have liked something more like an analogue signal where a microcontroller can do a bit of processing on the signal strength and duration to vary the sensitivity of the device. For some people, the binary behaviour would be seen as a plus as you can use the device without a microcontroller at all. For example, feed the signal to a latching relay to trigger an alarm.

Tried with Arduino and esp8266 and poor performance