Trippy RGB Light

This is another project that modifies the MiniPOV kit, similar to the LED Cube project I did previously. This time, instead of an LED matrix, one Red, one Green, and one Blue LED are used to create a multi-color light show by utilizing pulse-width modulation of the AVR's output. The construction is very similar to the LED Cube in that I also built the RGB from scratch. I did not, however, include an ISP header this time around because I felt the original program was adequate for a project of this scale. If I later decide to rebuild this project using multiple better quality LEDs I will definitely include an ISP header to be able to reprogram the RGB for other light shows.

In order to program the RGB Light I had to modify the makefile code for use with my USBTiny ISP in the same manner I did in the LED Cube project. This project is very simple to build and it produces an interesting light show. With some better quality LEDs with more diffuse viewing angles this could be even better. I will most likely rebuild this at some point in the future with more appropriate LEDs. Check out the video of my Trippy RGB Light in action (with a plastic bag between the RGB Light and the camera to diffuse the light for better color mixing).

Links

• Trippy RGB Light Schematic
• Trippy RGB Light Firmware (C code)
• Trippy RGB Light makefile
  

LED Camera Light

This is project is originally from ProdMod and I built my version of one in about an hour. I had been looking for a way to put a camera light on my digital camera, especially for video, and this project fits the bill perfectly. All this camera light consists of is a modified 4-AAA battery case (with built-in switch) which has a 3/4" long 1/4" cap screw passing through it and 3 white LEDs wired to the batteries. To use it you simply thread the screw into the tripod mount on your camera and turn it on.

I used a different parts source than the original article, getting both the white LEDs and AAA battery case from Mouser Electronics. The cap screw can be purchased as a pack of 2 from Home Depot for $0.88. Other than that my camera light went together the same as the original article, with the exception that I used a 15 Ohm resistor instead of a 10 Ohm to protect the LEDs. I chose this in order to add the flexibility of using regular alkaline batteries or rechargeable batteries. Since alkaline batteries produce 1.5 Volts typically, three alkalines produce 4.5 Volts. Rechargeable nickel-metal-hydride batteries produce 1.2 Volts typically, so three batteries produce 3.6 Volts. This voltage differential means the current limiting needed to keep each LED's current draw under 2o mA is different if using alkalines or NiMH batteries. For the LEDs I chose from Mouser, the 15 Ohm resistor used with alkalines produces a current of 63 mA or 21 mA per LED. If using NiMH batteries this would amount to approx 17 mA per LED. Therefore, the 15 Ohm resistor is a good compromise that allows me to not worry about battery type.