This RFID card has a lot of nice features. But the one that stands out the most is the ability to learn the code from anther RFID tag or card.
You can see that the board includes an etched coil to interact with an RFID reader. This is the sole source of power for the device, letting it pick up enough induced current from the reader to power the PIC 12F683 seen on the upper left of the board. The underside of the PCB hosts just three components: an LED and two switches. One of the switches puts the device in learning mode. Just hold down that button as you move the board into the magnetic field of the reader. While in learning mode a second RFID tag is held up to the reader. It will identify itself and the emulator will capture the code sent during that interaction. This is all shown of in the video after the break. We wonder how hard it would be to make a version that can store several different codes selected by holding down a different button as the emulator is held up to the reader?
If you want to build your own card reader too here’s a project that does it from scratch.
Continue reading “RFID emulator card includes a learning mode”
Hone your fundamental understanding of computer systems by completing this online course called NAND to Tetris. The idea is to develop each fundamental unit that goes into making computer programs a reality. This starts with logic gates, which are put together into modules that eventually become a functioning computer. From there you need an operating system, a compiler, and eventually you’ll be playing a game of Tetris which you programmed yourself.
It’s certainly not an easy journey, but if you have a computer at your disposal you should be able to make it all the way through the course. There’s a software suite which includes a hardware simulator so that the computer you’re building can be assembled using HDL instead physical components.
The concept is discussed in this TED talk given by [Shimon Schocken]. It is also embedded after the break and in addition to the NAND to Tetris project he shows off some self learning software on the iPad. To us it seems very much like the learning software [Neal Stephenson] envisions in the Young Lady’s Illustrated Primer from his Diamond Age novel.
Continue reading “Programming Tetris by first building a logic gate, then a computer, then…”
[Fall Deaf] built an Arduino based universal remote control system. It uses a shield which has both an IR receiver and transmitter. This gives it the tools to learn codes from your existing remotes and play them back in order to control the devices. This functionality is really nothing new, but we think the user interface he developed for the system is absolutely fantastic!
Software is web-based. You can simply point a remote at the Arduino and push a button. The receiver will store the code which can later be assigned to a virtual button. The image above shows the channel-up option being created; it will be added to the list once confirmed. From there any web enabled device – smart phone, tablet, netbook, etc – can be used as the remote for the system. The only feature we think is missing is the ability to alter the layout of the buttons, with larger areas for the most frequently used commands.
After the break you can see a demonstration of this system, as well as the one extra feature we haven’t touched on yet. [Fall Deaf] included a Piezo element in the hardware design which lets him knock on his coffee table to use the remote if a smart-device isn’t close at hand.
Continue reading “Flexible web interface makes the universal remote nearly perfect”
[manuka], aka [Stan Swan] is a teacher in New Zealand who enjoys enlightening his students on the wonders of electrical circuits. He primarily uses “snap connector” circuit kits, sold under the BrainBox name in NZ, for his interactive labs as they can be easily manipulated by pupils of all ages.
While the kits are great, he says that the range of experiments they provide can be a bit limited, so he decided to swap out the kit’s sound module for something far more useful – a PICAXE-08M. The space left by removing the sound module was pretty small, but [Stan] got everything to fit without too much hassle. His modification allows his students to program the PICAXE, as well as utilize four of the uC’s output pins.
Needless to say, the addition of the PICAXE module was a huge hit with his students, allowing them to create far more exciting circuits. [Stan] has been revising his system over the years, adding extra output pins, enabling lamp and motor control, as well as tweaking his setup to respond to IR commands.
We think [Stan’s] work is pretty awesome, and we’re still wondering how this flew under our radar for so long. He says that his students vary from preschool kids to centenarians, so if you’ve got someone that you would like to introduce to the fun world of electronics, we suggest picking up one of these kits and getting to work.
Many of you may have seen these fun little toys in museums or possibly even in school. Instructibles user [brazilero2008] takes us through the process of constructing one on our own.
Most of this toy are constructed from fairly household materials like foil, paper, straws etc. The fun part comes when you find the power supply. [brazilero2008] is using an air ionizer that he found at a rummage sale, though any high voltage DC source should work. He shares some tips on how to save time and effort creating the balls on the end by telling us how he did it the difficult way.
We admit this isn’t the most attention grabbing project, but we think it would be a fun educational weekend project.
[Emily Daniels] has been teaching interactive electronics workshops geared towards children for some time now, recently holding a session that demonstrated how batteries work in a pretty novel fashion.
She wanted to keep things safe and simple due to the class size, so she didn’t want to rely on using soldering irons for the demonstration. Instead, she showed the children how batteries function by building simple voltaic cells with paper flowers, salt water, and LEDs. The paper flowers’ absorbency was used to act as a salt bridge between the wire pairs that adorned each petal. After salt water was applied to each of the flower’s petals, the center-mounted LED came to life, much to the amazement of her class.
The concept is quite simple, and the LED flowers are pretty easy to build, as you can see in her Instructables tutorial.
We think it’s a great way to demonstrate these sorts of simple concepts to kids, and hope to see more like it.
[via Adafruit blog]
We realize that not everyone out there holds a degree in electrical engineering or has the ability to tell NPN transistors apart from PNP transistors by taste alone, so we occasionally like to mention things that appeal to the beginners in the crowd. While there is a clear division between Arduino supporters and detractors, it is hard to deny that the devices have their place, and can be quite useful when exploring certain electronics concepts.
For the supporters out there, [John Boxall] has put together a site jam-packed with Arduino tutorials covering a wide array of concepts and techniques. We have covered his work before in relation to specific topics, but we felt that his site deserved mention as a whole. His tutorials cover some of the most basic concepts such as lighting LEDs with the Arduino, and work their way to more advanced subjects, lesson by lesson.
He is not satisfied with simply introducing a concept and handing out a sketch that does the work. He takes the time to expand on the concepts, giving the reader enough detail to use their new-found knowledge in later projects. If you were to follow his tutorials from beginning to end, you would be exposed to LCD screen control, shift registers, real-time clocks, I2C bus communications, and more. These skills and concepts can be carried on to future projects as well as other micro controllers, making his tutorials a very valuable learning tool worth checking out.