@AWI Hey I did buy this Sharp Sensor, now I am trying to get the data of the cms, using the chart that comes in the datasheet that is the same one you pasted here. However it seems I am doing it wrong because the centimeters I am obtaining don't match reality, Could you please tell me which relationship you used? thanks

@gregl It's a university project. To play some sounds strictly while the person is taking a shower, and needs to be activated automatically, also turn off automatically

@AWI Oh really? I read somewhere that the IR output wasn't linear, will check again. thanks

@boozz I thought about it but the waterproof seems like a probable issue here. I didn't know if there were any waterproof sensor of this type, and then the cables maybe a safety issue, so I moved to a proximity sensor located on the walls or roof.

Hi guys.

For one of my university projects I need to detect the presence of a person in the shower. In order to do that what I have in mind is use a proximity sensor. If the target is in a distance range (let's say 20 to 50 cm) It will assume that the person is in the shower when the distance measure is no longer in this range then it will mean that the person left the shower. I need to detect all the time of the person in the shower (meaning when he/she gets in and then out). I have read a lot of info and forums to properly choose the type of sensor. However I still don't have a clear answer. About the Ultrasonic proximity sensors I know that they are cheap and more accurate by it can be affected by Temperature, humidity and some ambient noise, all of them which happen in a shower. The other option an Infrared one gets affected by lightning conditions and the surface of the target, and it doesn't have a linear output. The last option I checked is a PIR sensor I know it senses Temperature of the target, but I don't know if it will be affected by the running hot water and also is more expensive. In general, I don't know how the running hot water will affect the detection of the person in shower. Also,so again I don't know how this will work. Sorry for the huge amount of questions, I am a little bit confuse with all the factors to have in mind. I am hoping someone out there can help a lost newbie like me and give me a suggestion. Thanks a lot