Science Projects

NEW PRODUCT – SMT Breakout PCB for 48-QFN or 48-TQFP – 3 Pack! – Beguiled by a fancy new chip that is only available in a QFP or QFN pinout? This breakout PCB set will make your life much much easier and get you prototyping faster than ever. One side has a 48-QFP pin out with traces going to two rows of 0.1″ spaced holes, the other has 48-QFN (7mm body). Solder your chip to either side and you’re ready to rock on any solderless breadboard. There’s even a THM pad on the opposite side of the QFN body pad so you can fill it with solder for a heat sink and/or connect a wire to it (say when the pad must be grounded). Each item comes with three PCBs, each PCB is identical and can support either a 7mm square QFP or 7mm square QFN chip. Standard thickness PCBs, with 0.7″ spacing between the two rows. The PCBs may come on a supporting strip of PCB, simply snap them off to use! In stock and shipping now!

The Register is reporting  that Boise University PhD candidate Joshua Kiepert has built a 32-way Beowulf cluster from Raspberry Pis. ““In order to keep the cluster size to a minimum while maintaining ease of access, the RPis were stacked in groups of eight using PCB-to-PCB standoffs with enough room in between them for a reasonable amount of air flow and component clearance,” he writes. “This configuration suited our needs for power distribution very well since it allowed for a power line to be passed vertically along each stack.” “Using this orientation, four RPi stacks were assembled and mounted between two pieces of acrylic. This created a solid structure in which the cluster could be housed and maintain physical stability under the combined weight of 32 Ethernet cables.” US boffin builds 32-way Raspberry Pi cluster • The Register.

Knowing that this desk was built from scratch is pretty impressive. But the motorized legs that raise and lower the desk to any height really puts the project over the top. Surprisingly this started off as a computer case project. [Loren] upgraded his hardware and couldn’t find a case that would organize it the way he liked. His desk at the time had a glass top and he figured, why not build a new base for the glass which would double as a computer case? From there the project took off as his notebook sketches blossomed into computer renderings which matured into the wooden frame seen above. Much like the machined computer desk from last December this uses motorized legs to adjust the height of the desk. These cost about $50 each, and he used four of them. If you consider the cost of purchasing a desk this size (which would not have been motorized) he’s still not breaking the bank. This battlestation is now fully functional, but he does plan to add automated control of the legs at some point. We think that means that each has an individual adjustment control which he wants to tie into one controller to rule them all. Filed under: home hacks

This is an 125 kHz RFID reader that is based on ATtiny13 micro-controller and an LM358 Operational Amplifier. No special RFID chip is used. The reading, decoding and printing the unique ID from 125 kHz RFID tags is made entirely in software by ATtiny13. 125 kHz RFID reader based on ATtiny13 - [Link]

NEW PRODUCT – Adafruit NeoPixel Digital RGB LED Weatherproof Strip 30 LED -1m – You thought it couldn’t get better than our world-famous 32-LED-per-meter Digital LED strip but we will prove you wrong! These NeoPixel strips have 30 digitally-addressable pixel LEDs per meter and are very affordable and are only 12.5 mm wide, 10 mm if you remove the strip from the casing. There are some things to watch for: These LED’s use about 9.5 Watts max (~2 Amps @ 5V) per meter. The max rating is assuming all the LEDs are on full white, usually the actual current for colorful design is about 1/3 to 1/2 the max current. A good power supply such as our 5V 2A or 10A supply is key! To make the strip thin and easier to manufacture, the controller chip is inside the LED, which is kind of cool, but also means that the chip only uses a single pin for input and a single pin for output. The protocol used is very very timing-specific and can only be controlled by microcontrollers with highly repeatable 100nS timing precision. We have example code for using with the Arduino Uno/Mega microcontroller at 8MHz and 16MHz, but it will not work with the Raspberry Pi, Basic Stamp, NETduino, any other interpreted/virtual machine microprocessor or any processor slower than 8 MHz. For those processors, check our 32 LED/meter digital LED strip which has SPI-like input/output and works well with Pi, NETduino, and other processors. The way the pixels are controlled by an Arduino, the entire strip must be buffered in memory, and we’ve found many Arduino UNO projects only have about 500bytes of RAM available after all the extras are included – enough for about 150 LED pixels. If you want to drive the entire strip and have some other libraries included, you may need to use a Mega. There are 30 RGB LEDs per meter, and you can control each LED individually! Yes, that’s right, this is the digitally-addressable type of LED strip. You can set the color of each LED’s red, green and blue component with 8-bit PWM precision (so 24-bit color per pixel). The LEDs are controlled by shift-registers that are chained up down the strip so you can shorten or lengthen the strip. Only 1 digital output pin is required to send data down. The PWM is built into each LED-chip so once you set the color you can stop talking to the strip and it will continue to PWM all the LEDs for you. The strip is made of flexible PCB material, and comes with a weatherproof sheathing. You can cut this stuff pretty easily with wire cutters, there are cut-lines every 1.3″/3.4cm (1 LED each). Solder to the 0.1″ copper pads and you’re good to go. Of course, you can also connect strips together to make them longer, just watch how much current you need! We have a 5V/2A supply that should be able to drive 1 meter and a 5V/10A supply that can drive up to 10 meters (depending on use). You must use a 5V DC power supply to power these strips, do not use higher than 6V or you can destroy the entire strip. They come in 5 meter reels with a 2-pin JST SM connector on each end and separated power/ground wires. These strips are sold by the meter! If you buy 5 meters at a time, you’ll get full reels with two connectors. If you buy less than 5m, you’ll get a single strip, but it will be a cut piece from a reel which may or may not have a connector on it. To wire up these strips we suggest picking up some JST SM plug and receptacle cables. If you want to connect to the input of a 5 meter cable (to wire it to power and a microcontroller) please get a receptacle connector. If you want to connect to the output, get a plug cable. If you are getting a less-than-5 meter strip, you’ll probably want one of each to make it easy to connect and disconnect. You will also probably want a 2.1mm DC jack to wire in so you can connect one of our wall adapters to power it. Technical specs: 12.5mm (0.65″) wide, 4mm (0.16″) thick with casing on, 33mm

Spanish architect Erik Morvan has infuriated city officials over his proposal to construct a 1,000 foot “space” hotel complete with a 24-hour mall, a marina and 2,000 hotel rooms, where windows would feature touchscreen videos of distant galaxies. via dezeen: The developer, Mobilona Space Hotels, based in Los Angeles, promises that “Mobilona Space Hotels™ will offer an out of this world experience for guests who wish they could travel to distant galaxies. The new hotels in Barcelona, Los Angeles and Hong Kong will be constructed by a multinational consortium under the leadership of Mobilona’s Global CEO Jerome Bottari and represent an estimated value of over $6 billion. The project hasn’t gotten through the first stages of government approval, but we have to give the developer credit for having the chutzpah to try…then again, they do talk to extraterrestrials too…

Tutorial: BeagleBone Black: Installing Operating Systems @ The Adafruit Learning System The BeagleBone Black includes a 2GB on-board eMMC flash memory chip. It comes with the Angstrom distribution factory pre-installed. You can flash new operating systems including Debian, Ubuntu, Android, and others. The following pages will illustrate the steps to getting the latest of each type of supported distribution onto the on-board eMMC. In addition to the eMMC, you can also boot directly from a microSD card similarly to the original BeagleBone. We’re starting out with instructions for Angstrom, but hope to add to it in the future!  If you don’t have a BeagleBone Black yet, you can add your name to the list to be notified for when we get them back in stock.

Philip Peter writes: I always like a challenge, so when I saw [simpleavr]s vusbtiny programmer, I started to wonder how small I could make an AVR programmer. All in all I’m pretty pleased with the result.The schematic is almost the same as the original one. I only added a LED an resistor to indicate a proper power supply. Minimalist AVR programmer - [Link]

Philip designed a simple component size and silkscreen reference board: since I kept checking old projects to figure out which silkscreens worked, and which didn’t, I made myself a simple reference board. I also included some common SMD component sizes, just to keep me from thinking 0402 was a viable default size. [via] Simple silkscreen reference board - [Link]

An application note from Microchip: Practical guide to implementing Solar Panel MPPT Algorithms (PDF!) This application note describes how to implement MPPT using the most popular switching power supply topologies. There are many published works on this topic, but only a tiny portion of them show how to actually implement the algorithms in hardware, as well as state common problems and pitfalls. Even when using the simplest MPPT algorithm with a well-designed synchronous switching power supply, it can be expected that at least 90% of the panel’s available power will end up in the battery, so the benefits are obvious. [via] Practical guide to implementing Solar Panel MPPT Algorithms - [Link]