Hot Glue LED Matrix Lamp

thingiverse

An intriguing light display utilizing sixty-four adhesive sticks and one hundred twenty-eight WS2812B RGB LED strips. This project is based on "Fiber Optic" LED Matrix by jbumstead (https://www.instructables.com/id/Fiber-Optic-LED-Matrix/). Design -------- Utilizing OpenSCAD, the objective was to replace the 12mm Diffused Digital RGB LED used in jbumstead's design with affordable WS2812B RGB strips and to create a container for the LEDs and electronics as thin as possible, enabling cheaper seven-millimeter adhesive sticks to be employed. Printing/Assembly ------------------- The only part requiring supports is "Hot Glue Matrix - Bottom.stl." The top and bottom LED/glue stick holders have an additional hole to run wires from the bottom to the top section. I used a transparent drinking straw to hold the wires (See image). All one hundred twenty-eight WS2812B LEDs are wired in series starting at the bottom and finishing at the top. Channels are designed to maintain the strips in position, and I employed blue painter's tape to secure them in place once they were wired up. A word of warning: the seven-millimeter adhesive sticks obtained from eBay are approximately one hundred meters long. I discovered that they varied slightly. Mine arrived in packs of thirty so I had ninety sticks to locate sixty-four of similar length. Additionally, I needed to increase the hole size using a nineteen-sixty-fourth inch drill after printing to make them easier to fit into the holes. Once you have inserted all the adhesive sticks into the top and bottom sections, ensure that the height between the top and bottom sections is uniform around the entire perimeter. Once you have it square, remove the four corner ones and super glue them back in place. This renders the structure relatively robust. Be cautious about the orientation of the LED strips. The design only allows the strip to be installed in one direction (there is space for the small capacitor that sits beside the WS2812B LED). On the top section, DIN starts at the top-to-bottom connection hole. On the bottom section, DOUT finishes at the top-to-bottom connection hole. You must connect the strips by wiring each strip together. You need to do this off the printed former as you cannot connect them while they are upside down. Each strip is spaced fifteen millimeters apart from its center. Set up a small jig to facilitate the wiring and then transfer the strips to the former, using tape to secure the LED strips in place. I employed wire-wrap wire to connect the strips. Parts used ------------ Sixty-four - seven-millimeter by one hundred millimeter adhesive sticks (ebay) One hundred twenty-eight - WS2812B sixty per meter (ip60 non-waterproof) One Arduino Nano One 3A Mini DC-DC step-down converter volt regulator One 10K 1/4W 5% resistor One 330R 1/4W 5% resistor One 470uF 10V small profile capacitor One 10K lin forty-five millimeter slider potentiometer (thirty millimeter stroke length eg: Bourns PTA3043) One small push button One small rocker switch One DC power socket (panel version) One drinking straw to hold wires going from the bottom to the top section. PCB ---- Eagle files are included. I created my board using the toner method. You can simply use a piece of proto board if you prefer, as the schematic is very straightforward and easy to wire up. The four mount holes should be drilled out with a two-point-five millimeter drill and tapped with a three-millimeter tap. I employed six-millimeter M3 screws to secure the board in place. Software --------- Work-in-progress - Test sketch only.