[youtube=http://www.youtube.com/watch?v=vfIiLE0BhE8]
The guys at Nerdkits have put together this tutorial on connecting a PS/2 keyboard to a microcontroller. Though this tutorial is written for one of the kits they sell, you should be able to apply this to pretty much any microcontroller. It is also a lesson in using interrupts instead of polling. They have several pre built examples ready to download as well as source code for the basic setup.
[via HackedGadgets]
In life and embedded systems timing is everything. Give [Frank’s] web-based timer calculator a try. Set your system clock resolution (in hertz making sure you account for any system clock divider), select your timer resolution and prescaler, then calculate based on desired ticks, overflows, or real time. He’s built this with the AVR chips in mind but it should be handy for any family of microcontrollers.
Of course none of this is rocket science, but if you’re trying to use one timer for two differently synchronized events this can save you a lot of trial and error time.
[drj113] posts his cool word clock. After seeing a similar clock on an industrial design website, he set out to make his own version. He made custom pcbs with the toner-etch method. The front is a solid piece of copper clad board and the light shines through the etched areas. It’s powered by a PIC microcontroller and uses approximately 120 ultra bright LEDs. [drj113] has all of the circuit board diagrams, silkscreens, etch negatives, and code on the intructable so you can build your own.
[youtube=http://www.youtube.com/watch?v=Y6kECR7T4LY&feature=player_embedded]
[Dan Ros] and the mbed team sent in their hack of a twitter talking Big Mouth Billy Bass. Originally the hack simply had an mbed micrcontroller and an SD card with some wav files allowing Billy to say classic quotes. Wanting to go further however, they used the mbed’s HTTPClient library to grab Twitter updates, and then have Billy say them out loud! Check out some other cool projects the mbed team has in the cookbook.
But wait, whats an mbed? We didn’t have a clue either!
Some researched reveals it is a powerful new microcontroller and prototyping board. With some features such as direct ethernet and USB connections right on the chip, as well as PWM, serial, analog, and more. What really stoked us is how it acts much like a USB thumb drive. Drag and drop your binary files, and it’s programmed! The only downside, at $100 it can be a bit more of an investment compared to an Arduino PIC. Could this be the next big prototyping tool that beats all others? Lets hear it in the comments!
[Update: The mbed can be had for a limited time pre-order price of $60 not $100 – Thanks Dan and the mbed team!]
The folks at Openschemes.com have written up an article on how to convert a USB serial port adapter to a low voltage serial interface for interfacing with microcontrollers. Though you can always just buy one, this is a fairly quick and cheap solution, especially if you are in a pinch or don’t have access to a retailer. The specific models you should watch for, are the ones with two chips, a microcontroller and a line translater.They go through the process of finding exactly where to patch in to add an extra interface. It only takes a couple wires and you are ready to go.
Not only can you use this as your serial connection to another microcontroller, but you can actually take control of the one on the board itself. If you load it with the drivers from TI, you gain access to the flash memory and can do whatever you want. They don’t go into much detail here though, stating that they’ll write another article on that.
We thought this little bugger looked familiar so we went digging through our archives. Sure enough, we found this system in action back in January of 2008.
[via Hacked Gadgets]
[youtube=http://www.youtube.com/watch?v=QNBg_jWjBmI]
When we first posted [Matthias_H]’s USB reader for SNES game carts, it was met with enthusiasm. The snega2usb allows you to play SNES and Sega games on your pc right off the cartridge. The latest revision is even more amazing than the first. [Matthias] has added the ability to read Sega Genesis/Mega Drive cartridges as well as the ability to save games directly to the cartridge. The board has also been updated from the rats nest it used to be to a smart looking dual sided PCB. So far [Matthias] hasn’t had any trouble reading cartridges, even ones with the SuperFX chips. [Matthias] also launched a site for the project where the lastest information on its development can be found. [Matthias] is getting close to a production version which will feature better firmware, console quality connectors and a shiny case.
[youtube=http://www.youtube.com/watch?v=W746qoZsrEs]
We’ve covered this sort of thing before, but there is something to be said for the simplicity of this tiny GSM alarm system by [trax]. The alarm system is designed to send the owner a text message when a sensor is triggered. This alarm only works with Siemens phones, but it shouldn’t be too hard to find one. The alarm is configured via a dip switch on the board and can also be armed and disarmed by text. The brains of this system is a PIC16F84A. The code and schematics are included at the bottom of the page.
