LED Strip project

Hi all

I saw recently a video where someone has attached a LED strip underneath some kitchen wall units. What he had done differently to your standard on off strips was to use sensors to turn on and off each LED in the strip as you pass your hand under the units from either direction. Im guessing it was ultrasonic sensors but im not sure.

If you get the jist of what im on about would you say it was ultrasonic or something else? My only concern is to keep a low profile under the cabinets to avoid being able to see any of the electronics while in the kitchen and ultrasonic sensors although small are obviously much bigger than a flat led strip. Im planning to do this as my first Arduino project so hope this is doable for a beginner!

Typically you'd use a [u]Passive Infrared Detector[/u] (PIR).

Im planning to do this as my first Arduino project so hope this is doable for a beginner!

I've never used a PIR (except my alarm system has some kind of motion detector that I bought) so I don't know the details of hooking one up.* But if you search "PIR" and "Arduino" you should get plenty of hits.

Now realistically, this project doesn't need a "brain". It could be done with [u]555[/u] timers (and some other electronics). That is... your electronics don't need a programmable microcontroller.... You might still need a brain! :smiling_imp:

But if you are better at programming than electronics, or if you just want to play-around with the Arduino and do something useful, the Arduino is a good (but more expensive) choice. It would make a GREAT first project! You'll still need some driver circuitry (or a relay, etc.) to "boost" the voltage & current to your LED strips. (Each Arduino I/O pin can only directly power about one "regular" LED.)

* P.S. After scanning the Adafruit link I gave you, it looks like you just need power and maybe a pull-up resistor.

Thanks for the comments :)

Ive just found another project that i believe was using the same tech to achieve my goal. Rather than PIR it looks like a IR tx and rx. Only difference to the below is that i wanted a stip of LED's rather than a block area.


I imagine for this i would need microcontroller as i need to sense movement, turn on the corresponding LED and keep it on, and then with a second sense of movement turn off. For example if i pass my hand under the cabinet half way along the strip, only that half will activate, and the other half remains off. Hope that makes sense.

Guess my project will start with breadboard and a single LED, then work my way up to a whole strip. Im was thinking of using the RGB SMD 5050 strips but wonder if a simple circuit of LEDs would be easier to work with.