Over at SpriteMods, [sprite_tm] realized that a microcontroller could be used as a boost converter to power itself. A boost converter steps up voltage from a battery by switching the output of a coil. First, it is tied to ground so a magnetic field can build up in the coil. It is then released as a higher voltage than the input. Normally dedicated chips do this at an incredibly high frequency, but the PWM signal from an AVR works well enough. This can be used in low-power situations where space is an issue.
[Kevin Gorga] submitted this PIC controller based wire tracer to a project contest last year over at circuit cellar.A 125Khz signal is injected to the target cable and a pickup coil is used to detect the field and identify the wires location. You can grab the full project schematics and code here. The rest of the entries are pretty sweet, so be sure to check them out.
Via [ladyada], [Raijuu] combined some ideas from [Ladyada]’s boarduino and [evilmadscientists] Atmel business card created his own single sided (for easy etching) project board for ATMega8/128 projects. You can tell that the design is an expression of frustration from past projects; We can definitely appreciate features like separate power and multiple sockets on each pin. (We’d probably consider adding some soldering points to allow for permanent connections.)
I was starting to wonder when [Bruce] would send in this years final projects from the Electrical and Computer Engineering students at Cornell University. The first project looks like a great one for the green geek – a controllable power usage monitoring power outlet. The music geeks should dig midi trumpet interface, but the car geeks might have problems keeping away from the soldering iron after they see the CAN bus SD card data acquisition system. There are plenty more, so go check em out.
[Yuri] spent some time building a computer controlled, arduino interfaced beer brewing rig. A cooler serves as a mash tun, while the arduino controls a steam source that’s used to raise the temperature of the mash as desired. A java app talks to the arduino to set the temperature parameters and monitor the steam boiler. You can catch a nice video walkthrough of the setup, see some screen shots of his java interface.