interactive projection mapping

Hello everyone !

I am about to buy a projector (optoma 142X) for my small architecture firm and I would like to
make an interactive mini installation with it. The office area is in the ground floor of a crowded road and people passing by till late at night.

The afternoon , when the office is closed I want to put a motion sensor and when the people passing by a ‘‘signal’’ will be generated through the sensor and a projection will appear in the projection screen .
The ‘‘in between’’ missing part is an arduino board ? How difficult is to achieve that kind of interactivity ?

thank in advance


I just found this , it was that simple ?


no help for the neewbies !


Well your picture seems to show that if you're running the projector from a computer that you're leaving on you don't really need an Arduino.

OTOH finding a motion detector that works through glass could be difficult or can you position the detector outside? And isn't it a bit too late to switch something on as people are already passing the window?


Of course some different project (although similar situation) - maybe some inspiration:

thank you very much for the replies !!! :smiley:
I attached a simple plan of the office area to help you understand better my thought !

@ Uxomm, I really liked the sophisticated project but I am not interested in doing something that complicated ! I just need the sensor to ‘‘trigger’’ the the projection… that’s all !

@ SlipsticK, yes the sensor it will be placed outside , if the range will be something like 170 degrees or if I have tilt a bit the sensor itself , it’s not the main problem for now , although , I would love to hear a suggestion about what usb motion sensor to buy … looking on ebay this morning is a bit confusing …

The glass facade is 4 meters long and you are right that it’s a bit late to activate the projection but it will be a small clever 1-2 sec projection and not a boring 30sec video … something like that :

(actual photos of the office area can be found here :

thanks again!!

Weekend Project: USB Motion Detector (PDF) - Make: seems something like what you're talking about.

Alternatively it may be practical to use one of the many wireless PIR detectors but it's not something I personally have tried. That would save running USB cables through the walls. In that case an Arduino with a 433MHz receiver may be one way of getting it connected to the PC.

Interesting project.


thank you Steve! I’ll take a look and I will keep updated asap :slight_smile: