[nmcclana] wrote out this very detailed instructible on building Mr. Burns, a sun burn alarm. Enter your skin type, sunscreen type, and UV levels for the day and Mr. Burns will let you know when it is time to go seek shelter or re-apply that sunscreen. Built on a Propeller platform, he’s using a blue LED as the UV sensor. He mentions that the device is fairly accurate, however people tend to put sunscreen on too thin and that will throw off the readings. There is a video of it in action on the instructible.
This little art piece might be just the thing to add that mad scientist look to your room. It’s called the Coachella lamp and it makes use of several throwback display devices. At the top an Argon discharge lamp puts out ultraviolet light. Protruding from each of the four sides you can see a set of decatrons. There’s also four Nixie tube bar graphs standing tall from each corner of the base. The final touch is the colored glow in the center which is provided by LEDs. We’ve embedded some video of the device after the break.
The lamp is powered by a wall outlet and controlled with an Arduino. We’ve seen deactrons used as timing devices and would love to see some clock functionality added to the lamp. Trying to decipher the time from the different Nixie displays would put this up there with some of those other hard to read timepieces.
Tired of those awful sunburns? [Nikko Knappe's] UV sensing glasses will warn you before you become crisp and red as a lobster. The bump added to the bridge support hides a TSL230R light frequency sensor. The device automatically switches on when the arms are unfolded and starts tracking cumulative exposure. If it detects a rising UV level, or you are about to burn based on skin type, an LED inside one arm of the frames will flash to inform you.
This has some potential if you think David Brin’s Earth outlines how climate change is really going to play out. Either way it’s still fun and we give bonus points to [Nikko] for disguising the lilypad that controls this as a flowery hair-pin.
[Jeremy] had some chips on hand that included EPROM. We’re not talking about EEPROM, we mean EPROM that need a UV light source to erase. Most people don’t want to drop a few hundred dollars on a dedicated EPROM eraser, there must be another way.
Boy, EPROM really suck. But so do pacifiers and he already had a solution for exposing those to UV. He pulled out his $30 UV pacifier cleaner and tossed the chip inside. Two times through the cleaning cycle and the data was gone. We’ve looked into using UV LEDs to do the job but some experimentation shows that it doesn’t work. These pacifier cleaners are cheap and easy to get a hold of. The real question is are you still using chips that require UV for erasing?
[Kizo] repurposed a flatbed scanner to use as an exposure box for making printed circuit boards. Exposure time is controlled by an AVR ATtiny2313 microcontroller. The device is connected to a separate display board to control four 7-segment displays using one shift register for each. Time is set in ten second increments and once started, switches on the lights with a relay. Once the right exposure time has been reached, the lights are switched off and a piezo speaker is buzzed. There’s no mention of they type of bulbs he’s using but they look like compact fluorescent with tin foil beneath as a reflector.
Ok, there aren’t any usefull applications we can think of for this one, but we want one really badly. This is a combination of a miniPOV, some UV LEDs, a CNC rig, and some glow in the dark paper. The Ghost matrix works similar to a dot matrix printer where it flashes the UV light to activate the paper. The final effect is very nice. Great job on this one.
[Barrett] sent in this hack he did to an airsoft pistol. He was using “tracer rounds” or glowing airsoft pellets and found that there was no commercially available way of charging them up with uv light before they are shot. He cracked open his pistol, removed the safety mechanism, and placed a UV led in it’s place. Now, when he turns it on, it charges up the pellets so they’re nice and bright. If he’s playing airsoft at night, won’t that bright purple light give away his position? yeah, we know he was probably just using that pistol to show the mod off.
AU Optronics Corp has unveiled a new LCD panel that doubles as a fingerprint scanner. Each pixel is equipped with 4 optical sensors, so a 320×240 screen would have a scanning resolution of 640×480. They have also experimented with different sensors, such as UV. You can see an LCD panel that detects and displays the UV index above. Why did they use a secondary display to show the data though?
