[Steven] was inspired by the BlinkM and Shiftbrite modules, but really wanted something that could be controlled via RS232. He decided to build his own RGB LED module capable of PWM that fit his needs. He’s using a PIC16F628 microcontroller as the base. Each module has 4 individually addressable LEDs with multiple intensities for each color. The units can be daisy chained as well. The schematics and PCB files are available on his site for download.
Futaba’s character displays can be interfaced using the standard 8-bit or 4-bit parallel LCD interface, or a simple two-wire protocol. The protocol type is set by resistors on the back of the display, so it’s not particularly easy to change without a hot-air rework station. Today we’ll demonstrate a serially-interfaced VFD using the Bus Pirate.
This is an interesting instrument. Part laser harp, part guitar, the Prism seems to have some potential. [Jeff-o] put some major time and effort into refinishing a guitar, building the circuit and putting it all together. He did a great job, the instrument looks fantastic and appears to work. We do have a request though; please post a video of it being played as an instrument. So many of these electronic instrument projects just spit out random noises. While we understand that some people are into that, we would love to hear some control. How about intentionally changing notes to make a melody? Based on the description, it should have control for pitch, and even speed of the oscillation. So let’s hear some music. We don’t care if you’re any good, just please play some music with it. If you would like to build your own, he has the schematics and PCB layout available for download.
[Eric] sent in this very informative writup on how to use Photo interrupters. These things can be used for many things, he lists pellet dispensing and limit switches. He found one in his junk box and realized he knew very little about it. After some exploring and research, he’s here to educate the rest of us. There’s a good breakdown of the circuit itself which is pretty simple as well as a test circuit and some sample code.
We’ve covered weed whacker bicycles before and you can even buy 66cc conversion kits now. [geoff390] posted a few videos over on YouTube about another motor option. In the first video embedded below, he goes over the basic parts of his bike. The chainsaw motor is mounted to the side of the back tire and a metal drive wheel extending from the chainsaw shaft makes contact with it. The motor assembly is mounted on a hinge and the friction between the drive wheel and the back tire is adjusted with a turnbuckle. He posted a more detailed second video in which he goes over some of the finer details of the bike and some of the issues he’s had. Read the rest of this entry »
[Michael Davis] sent in his homemade laptop tray. He does a lot of traveling in his Toyota Tacoma and was looking for a good way to mount his laptop inside. Unfortunately, [Michael] soon discovered that commercial laptop trays can be very expensive and difficult to install. He saw an opportunity in the empty cup holder in his car. Fifteen dollars worth of PVC pipe fittings and a piece of plywood later he had a laptop tray.
Strobit looks like it could be a project to keep an eye on. The entire project is open source, including the hardware. The aim is to build a low cost, low power, wireless enable arduino powered widget. This seems like it could really cut down on the development time of many projects we’ve seen here. Development is still ongoing but it looks like they’ve already implemented some mesh networking similar to the zigbee systems.
This project provides an opportunity to conduct near space experiments. The flight computer, BalloonSat Extreme, is controlled by a BASIC Stamp 2pe. The complete BOM with PCB artwork is provided. There is enough hardware to control cameras, servos, a Gps, and five digital I/O. The computer is also equipped with a 12 bit ADC to log experiment results. The device seems limited to 30KB of storage. Though the author suggests this memory limitation is more than adequate, we are wondering if an implementation of the Nyquist sampling theorem is in use at all. For further reading the author has provided information regarding Amateur Radio High Altitude Ballooning.
