Test 1 - Lowering trigger distance by soldering a resistor to the R-GN plates

The objective of the test was to lower the distance of the PIR-sensor, so that we could have two sensor inputs to our code, one that registers when a person is in the room and one that registers if a person is close to the product. After a bit of googling and youtube videos, the most reasonable solution seemed to be that it was possible to lower the distance of the RCWL-0516 sensor by soldering a resistor to the R-GN plates.

This surface was quite small and difficult to solder on. Either the solder tin didn't take or just broke off right away. After a lot of attempts we finally managed to solder some tin to the plates, enabling us to solder on the resistor. However, the tin broke off and took the metal off the R-GN plates, making it impossible to solder it on. This killed the sensor. 

After this, the other plates on the sensor were used to practice soldering technique, leading to the discovery that the easiest way to achieve this goal was to slowly build up a thin tin tower on top of each plate. After this, the resistor legs could be soldered to each tower for a connection.

(Burned R-GN plates and soldering on the other plates)

After several tries we managed to solder a resistor on the plates and tested the sensor with a different grade of resistor with no effect on the sensor range.

Test 2 - Attempt to lower the distance by replacing the first resistor on the front with a lower value resistor.

After some more research we found out it wasn't the R-GN plates you should solder a resistor to but to the resistor on the front of the sensor. It was not possible to solder another resistor on top of the built in resistor, so we had to cut off the existing resistor in order to solder our own onto the component.

After testing the sensor with the new resistor value the distance didn't change and it still registered motion at its default range which was around four to five meters.