Rainbow Light Painting With Adressable Leds

I made this project to show people how to use an adressable leds strip and how to make light painting.

Edit : I just came to realize that I put the colors in the wrong order... So the illustration show a "upside down" rainbow. I did correct the code and the image of the code, but I didn't have opportunity to made new photos. Please Newton forgive me (you who use to say ther was seven color in the rainbow, superstitious fellow)

• 1x Arduino Uno
• 1x led WS1218 (adressable leds strip with n * 6 leds) (here I choose 18)
• Some cables
• 9V battery
• 9V batterry case with a switch
• A wooden stick or anything else to hold everything together
• A Camera that have a manual mode (we need mode B : long exposure) on a tripod and with delay or IR command

First connect the led strip like shown on the pictures (5V / + on the 5V pin of the arduino, GND / - on any GND pin of the arduino and Data / Din on the pin number 10 of the arduino (or any other I/O pin, but you'll then have to change the arduino code).

See the project on Tinkercad : https://www.tinkercad.com/things/je7bjMBL4Q0

Plug the arduino to your computer with the USB cable and upload the code shown above and provided below in the arduino using the arduino IDE (See https://www.arduino.cc/ to learn how to do that if you don't already know).

If everything is OK you should already see the led turn on and show the color of the rainbow as on picture

Connect the 9V battery either with the special arduino connection, or connect the + to the Vin pin of the arduino and the - to any of the GND pin of the arduino. Turn on the switch of the battery case and you should see the led turn on.

Set the camera to manual mode (M).

Push the AV button and use the scroll wheel to set the aperture to the minimum (the minimum aperture is the maximum F value!) F22 for example, to have the best depth of field.

Click on the ISO button and set the iso to a low value (100 to 400) to avoid any noise on the picture.

Use the scrolling wheel to set the duration to the number of seconds you wish for your picture. The greater it is, the longer the camera will "draw" the light movement.

And don't forget to set the camera to manual, to avoid the auto focus.

And now, just ask someone to wave that rainbow wand in front of the camera, take pictures and be amazed by the results!

Note : to avoid any movement blur due to your finger pushing the trigger, you can use delay triggerring or IR remote trigger.

Have fun and don't hesitate to post you picture below!

Thank you and may the force (and the light) be with you!