Just got a PIR sensor. PIR, as I understand, stands for Passive Infra Red. It’s a cool little thing that detects motion, or actually changes of infrared light. Infrared, in this case, is heat. So whenever a person, or part of a person, or perhaps an animal, or part of an animal moves infront of the sensor, it will trigger a response.

I connected the PIR sensor to an Arduino board to test it out. The PIR is connected to +5V, GND and a digital inputpin on the Arduino. Quite straight forward, but the inputpin also needs a pull-up resistor. The PIR sensor tiggers a GND if it detects motion, otherwise the trigger signal is not connected. Therefore, it needs to be pulled up to +5V.

I also connected a buzzer to make it the whole thing more spectacular.

The PIR, it turs out, was not really as stable, but after browsing around the net I found a fairly simple solution: to use +12V instead of +5V. This made the experience much more reliable, fun and useful!

So, now I’m working on making a PIR-project – something that is quite straight forward but fun. And not too complex.

More on this to come…