For our project, we want to use a sensor to detect if a person is sitting in front of our companionship sculpture. For this we are using the sensor RCWL-0516.

First test – Is it working?

We set up the sensor with Arduino and breadboard. Using an LED as indicator to light when the sensor detects a person or object moving. Our 1 st test was successful, and the radar sensor picked up movement both from the front, and behind of the sensor. However, finding out the range of the sensor is about 7 meters, the range of which it detects a person is too far, so we worked on how to decrease the range.

Second test - Range

Upon inspecting the datasheet, the range of the radar sensor can be adjusted by adding a resistor to the R-GN pins on the sensor. This is an optional resistor to decrease the range of the sensor, however you need to solder the resistor on yourself. A resistance of would bring the range from 7 m to 5 m. Decreasing the resistance further will further decrease the range. A resistance of about would decrease the range to about 20 cm which is suitable for our product.

We then soldered the resistance onto the R-GN pins but ended up burning off the patches destroying the sensor. We used a spare radar sensor for further testing and ordered a few extra radar sensors online.

Oopsiedoopsie!