Picture of Quick and Easy Arduino Nightlight
Honestly, how many people have been in this scenario (leave a yes or no in the comments) : It is 2:30 in the morning and you wake up with a need to do something whatever that may be (bathroom, forgotten homework assignment, project due in 5 or 6 hours, etc.) it takes you 5-10 minutes to find the light switch (give or take...)

My mother likes a night light for the bathroom but she didn't want one that stayed on all night so I needed one that could detect a person. Many thoughts popped up into my head on what sensors to use. I could us esuch as the Linescan Imaging Sensor Daughterboard by Parallax but that was overkill and too expensive. A cheaper solution would be to use a few ir leds with ir phototransistor but still too complicated. I also thought of the Ping Sensor from Parallax but too hard to program with my beginner standards in C and, it used too much power. (I'm more of a Spin and Assembly language person.) I finally looked through my sensors box and found...(...drumroll please...) ...Parallax's Passive Infared Motion Sensor! It was fairly inespensive ($9.99), it could work in the dark, and, I have had experience in programming these!

Step 1: Get The Required Materials.

1 of everything except where noted.

PIR Motion Sensor from Parallax
LED ( Preferably Ultra Bright White. I bought mine along with other colors at Ebay from this seller: http://myworld.ebay.com/led.shop*2010/?_trksid=p4340.l2559

They will compile your own personal mix of colors if you want them to...they will charge more but it is a personalized order. I also found this order of only white LEDs but very cheap.


Many jumper wires

Optoisolator/ optocoupler/ relay

Resistor. Define the value yourself.
imakethings3 years ago
Gud project but it can be done without using the arduino!
blinkyblinky (author)  imakethings3 years ago
Of course!

It can be but since I was entering this in a Arduino competition I used the Arduino. I could have used a transistor and possibly a Darlington transistor. Maybe I will make another one with a transistor...