‘tiny’ Power Supply Monitor

February 9, 2010 by Mike Szczys 13 Comments

[Manekinen] built a power supply monitor based around an AVR ATtiny13. Voltage and amperage are displayed on a 16×2 LCD character display (we’re not sure what the third number is… samples per second?). This is no small feat considering that the tiny13 is an 8-pin chip. He makes it happen by using the pins for both LCD control and ADC input. To make this happen the HD44780 compliant display is used in 4-bit mode. Check out the video after the break and hit up the non-translated page if you want to download the source code and PCB artwork. A note of warning, he’s using the RESET pin for I/O which means once you burn the fuses you’ll need a programmer that has High Voltage Serial Programming capabilities if you want to reprogram the chip. Continue reading “‘tiny’ Power Supply Monitor” →

Update: Adafruit Eagle Library, Now With Arduino

February 6, 2010 by Mike Szczys 9 Comments

Adafruit Industries has just added an Arduino shield footprint to their EagleCAD library. If you don’t know, the Arduino headers use non-standard pin spacing. Learn to deal with it, there’s too many Arduino shields in production to have any hope for a change in the future. This footprint should make it a lot easier to design your own boards. If you use this package make sure you’re getting the library from their github, they’ve been adding parts regularly. Setting up version control will make sure you always have the latest libraries.

[Thanks pt]

Battery Holder Reuses Blister Pack

February 4, 2010 by Mike Szczys 33 Comments

In need of a portable power supply, [Alastair] threw some batteries into an Altoids tin. The problem was he didn’t have a holder for these size A23 cells. Inspiration struck and he realized the blister pack they came in fits them snuggly and just needs some conductors to complete the circuit. He pulled some battery contacts from a broken CD player. Using foam-based double-stick tape he added some spring to the contacts and came up with a perfectly sized holder that works wonderfully.

We’ve tried making battery packs by wrapping the entire thing in clods of duct tape. This looks like it works a lot better and there’s still room to fit the batteries and a switch inside of this minty enclosure.

USB HDD Enclosure To DVD Connector

February 2, 2010 by Mike Szczys 123 Comments

This is a “why didn’t I think of that?” idea. [Alec] needed a way to connect an IDE DVD drive using USB. Rather than order a connector he pulled the circuit board out of an old USB hard drive enclosure and connected to his DVD drive. Bang, recognized and running.

This will prove extremely handy if you have a netbook without an optical drive. We’ve used Unetbootin to move Linux ISO images to a thumb drive in the past. In addition to getting around the lack of an optical drive, this saves burning the data to a piece of plastic. But, you should be able to use this with a Leopard retail DVD instead of a 16GB thumb drive for a Hackintosh conversion. That means you could install Leopard on a netbook without needing a Mac to transfer the disk image to your thumb drive first.

120v Switching

January 31, 2010 by Mike Szczys 52 Comments

[Kenneth] built a 5v controlled power outlet inside of a junction box. We’ve seen plenty of projects that can switch 120v outlets using 5v logic for refrigerator controllers, lighting controllers, or grow systems, but they almost always use solid state relays to facilitate the switching. This iteration uses mechanical relays along with the necessary protection circuitry. The project is housed in an extra deep single-gang box and allows for individual switching of the two outlets. You can see this connected to an Arduino switching two lamps after the break.

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Adafruit Eagle Library

January 21, 2010 by Mike Szczys 15 Comments

We love it when a PCB comes out right the first time. We’re careful enough with our designs that if something is wrong it’s usually a footprint problem, like we picked the wrong package for the components. Adafruit is helping to make the design process easier by sharing their Eagle library. Like the Eagle library version control we saw earlier in the month, this library is housed on github making it easy to stay up-to-date. The library includes many components (switches, crystals, IC’s, etc.), and fixes some prolbem-footprints, like 0805 surface mount pads.

Servo Hacked Linear Actuator

January 19, 2010 by Jakob Griffith 22 Comments

[AntonB] has modified a servo into a powerful linear actuator (think: changing rotational motion into linear motion). The process is simple enough, modify a servo for continuous rotation and then add the custom built actuating shaft. You do of course lose the precision of the servo, but a small price to pay to be able to lift ~20 pounds straight up. Inspiration for such a cheap solution came from his Planetary Surface Exploration Rover. Check out a video of both after the break.

[Thanks Eric]

Continue reading “Servo Hacked Linear Actuator” →