Invented 30 years ago, polymerase chain reaction , or PCR, is one of the greatest inventions of the 20th century. It’s the technique that allows researchers to map genomes, find genetic causes of diseases, create Jurassic Park, and match crime scene DNA to suspects. When PCR was first invented it was extraordinarily expensive, and even today commercial PCR machines cost about the same as a new car. There is an open source project for a PCR machine that costs about $600, but for his Hackaday Prize entry, [David] is knocking a few more zeros off that cost and building a machine for less than the cost of a fast food meal.
Despite being the work behind a Nobel Prize, PCR is conceptually fairly simple: A strand of DNA is unwound into two strands, an enzyme, or primer, is annealed onto these single strands, and then biochemistry happens, turning those single helix strands of DNA into a complete double helix, ready for the next replication cycle. The key of the PCR technique is getting the enzymes and primers to react. This is only done at a fairly fine range of temperatures, cycling between 90°C, then 60°, then 72°C.
The oldest models of PCR machines used multiple water baths, with newer commercial machines using something that probably justifies their cost. The OpenPCR project uses an aluminum heater block, but [David] is going for a modern twist on the old-school method. He’s trying to figure out how to exploit convection to get local temperature variations in a single vessel. How he’s going to do this is anyone’s guess, but building a PCR machine for $5 is pretty cool.
The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.
[HSP] got tired of locking his door with a key, so he decided to upgrade to a keypad system which he’s designed himself.
It uses an Arduino Mega with the standard 44780 display, a standard keypad, and the “key override” (shown above) for fun. The locking mechanism is a standard 12V actuator based lock which was modified to run off of only 7.5V, by softening up the spring inside and running it upside down (as to let gravity help do the work). The whole system draws less than half a watt on standby, and engaging the lock peaks at only 4-7W.
What’s really clever about this design is how he locks it from inside the room. He’s programmed the Arduino to write 1 to address 128 of the EEPROM — at power on it will increment this by 1, and after 5 seconds, it will reset to 1. This means it can detect a quick power cycle, so you can lock the door by turning it off, turning it on for a few seconds, and turning it off and on again — he did this so he didn’t have to make a button or console, or any kind of wireless control on the inside. Continue reading “Door Lock Provides Peace Of Mind With Real-Time Security”→
Hackaday took a trip to Detroit last weekend for the Red Bull Creation Contest. It was a blast, we had a lot of fun, and we were lucky enough to catch a glimpse at seven teams hacking, grinding, sawing, and soldering their way through the 72 hour buildoff.
Team Detroitus started their build with the idea of building a giant air cannon. The theme of the build was ‘reinventing the wheel’, but they apparently didn’t let that get in the way of building a giant double barrel air cannon, filling it with candy and stuffed animals, and shooting it, point blank, at children. I was wanged by a lemon Starburst, but that’s my favorite flavor anyway.
The biggest question about this new Pi was the CPU: the Broadcom SoC in the models A and B are looking a little long in the tooth right now, and an upgraded CPU would be a very, very welcome addition. There is no change. This is the same 700 MHz Broadcom chip with 512MB of RAM. There will not be a ‘magical, because you’re awesome’ RAM upgrade the original Model B saw early in production, either – there simply aren’t enough address pins in the SoC.
Despite not having an upgraded CPU, there are some neat features that addressed the complaints of the original Pi: The standard sized SD card socket is replaced with a microSD card socket that won’t stick out over the edge of the board. The ports are rearranged, with the analog video out on a TRRS plug with the audio. There are now four USB ports and an Ethernet port thanks to this chip, and mounting holes galore: they’re M2.5 holes in a square 58mm wide and 49mm high. Also included in the B+ is a completely redesigned power supply – the jumbo linear regulator is gone, replaced with an all-around better power supply.
The biggest change for anyone looking making a project with the Pi is the expanded GPIO header. This is a 40 pin header, with the ‘top’ pins identical to the original 26 pin header. Yes, all your existing Pi plates/shields/whatevers will still work. The new pins on this header include nine more GPIO pins, the I2S pins for the Wolfson audio card, and a pair of pins for an ID EEPROM. Connections to an ID EEPROM have been a feature of the BeagleBone for a while now, and this will allow the Pi to configure the appropriate I/Os and kernel modules at boot, depending on what Pi Plates are attached.
The best part about this is the price – it’s the same as the OG Model B. Using the same case as you old Model A or B is out of the question, but that’s totally what Kickstarter is for, right? You might want to grab one of those, because this is probably going to be the form factor for the upgraded Raspberry Pi 2.0 that will probably be released in a year or two.
CERN, the people that run a rather large particle collider, have just announced their most recent contributions to the KiCad project. This work focused on adding new features to the module editor, which is used to create footprints for parts.
The update includes support for DXF files, which will make it easy to import part drawings, or use external tools for more complex designs. New distribute tools make it easy to space out pads evenly. The copy and paste function now allows you to set a reference point, making it easy to align blocks. Finally, the pad enumeration tool lets you quickly set pin numbers.
CERN has already implemented a new graphics engine for KiCad, and demonstrated a new push and shove routing tool. The work plan for CERN’s KiCad contributions shows their long term goals. If you’re interested in what CERN is doing with KiCad, you can check out the CERN KiCad Developers Team on Launchpad.
After the break, watch a quick run through of the new features.
Does your Gated Community make you feel secure due to the remote-controlled gate keeping the riffraff out? Residents of such Gated Communities in Poland are now shaking in fear since [Tomasz] has hacked into his own neighborhood by emulating the signal that opens the entrance gate. Shockingly, this only took about 4 hours from start to finish and only about $20 in parts.
Most of these type of systems use RF communication and [Tomasz’s] is no difference. The first step was to record the signal sent out by his remote. A USB Software Defined Radio transmitter/receiver coupled with a program called SDR# read and recorded the signal without a hitch. [Tomasz] was expecting a serialized communication but after recording and analyzing the signal from several people entering the community it became clear that there was only one code transmitted by everyone’s remote.
Now that he knows the code, [Tomasz] has to figure out a way to send that signal to the receiver. He has done this by making an RF transmitter from just a handful of parts, the meat and potatoes being a Colpitts oscillator and a power amplifier. This simple transmitter is connected to a DISCOVERY board that is responsible for the modulation tasks. [Tomasz] was nice enough to make his code available on his site for anyone that is interested in stopping by for a visit.
Back in 1996, a group of engineering students at McMaster University set out to build a fully functional hot tub housed in a working car. They chopped up an abandoned 1982 Chevy Malibu and converted it into The Carpool.
That group of students graduated, and began work on the Carpool DeVille. Six years later, they’re ready to take it to Bonneville Salt Flats to claim the title of “world’s fastest hot tub.”
There has been some substantial modifications to the vehicle to make the Carpool a reality. A custom fibreglass tub was built to drop into the passenger compartment, and heat exchangers were added to the stock engine system to heat the water. The plumbing and pumps for the tub reside in the truck, while the original V8 engine is up in the front. A custom air suspension system allows them to carry the massive volume of water. There’s even a marine throttle to control gas and brake from the driver’s seat in the tub.
The folks behind the Carpool DeVille ran a Kickstarter to fund their race costs. The campaign is over, but you can still check out the story and pictures of the conversion. Since it was a successful campaign, we’re looking forward to seeing this custom vehicle out on the salt flats.