I am currently trying to set up the HB100 Microwave Sensor. I have built and am using the first amplifier circuit according to page 5 of the datasheet. I am using the FreqCounter library and its example code to test my setup. The frequency in serial monitor changes as I move in front of the sensor, thus it appears to be working.
Here's the issue, using my Arduino Uno on my PC, serial monitor shows values of 3 to 5 when no movement is detected. And when movement is detected, it shows 0 to 1. Now when I test the exact same setup on my Android phone instead of PC, using the Serial Monitor app, the results are INVERTED. No movement shows 0 to 1, mostly 0, and having movement shows a 3 or above value. I believe this is the correct and to be expected results.
Does anyone know why is this happening? Why am I yielding inverted results? I also understand that the FreqCounter library is over 4 years old, does that have any effect on newer versions of Arduino software(ie serial monitor)?