Using MatchBox Cars As A Switch

September 15, 2009 by Caleb Kraft 78 Comments

cars

[atduskgreg] posted this interesting setup to flickr. He’s using two toy cars as a switch. He has wired into their metal undercarriages so when they collide, the circuit closes. We’ve seen some pretty nifty home made interface items, but usually they are posted with a clear purpose or a project. This one is a little puzzling. Does he intend to keep using the cars or was he just fooling around? Is he working on a toy that does something when they crash? Was he merely bored and wanted to see what he could attach to his Arduino. We may never know.

Dual Voltage Power Supply

September 14, 2009 by Mike Szczys 29 Comments

dual_regualted_power

[Melanie] had some time this weekend so she whipped up a dual voltage power supply from parts on hand. This design plugs right into a breadboard and, unlike the last breadboard power supply we saw, provides two voltages at one time. 5v is delivered to one power bus while 3.3v goes to the other. Her design uses two linear low voltage drop regulators from the LF00 family (PDF datasheet) to accomplish this. Nice work!

Low-cost ARM7 Prototyping

September 10, 2009 by Mike Szczys 27 Comments

Do you find that the capabilities of your current microcontrollers are holding you back when you try to take over the world? Moving up to ARM7 architecture will put your projects in the same arena with the iPod and the Nintendo DS.

The BlueBoard-lpc214x is a prototyping board with a lot to offer. It incorporates two RS232 connections, USB, VGA, SD card slot, piezo buzzer, JTAG, audio out, PS2 keyboard connector, and a 2-line character LCD. The processor is an NXP Semiconductor LPC2148 with 512KB of programming space and 32+8KB of ram. The board also includes a 256KB i2c eeprom. This is a lot of prototyping power, but the low purchase price knocks our socks off: $40.90! Sadly, shipping would cost us another $20.43 but that’s still a lot of functionality for around $60.

Sample code and schematic are available for download. All of the pins for the microcontroller have jumpers and there are rows for pin headers around the processors if you want to patch in your own hardware. We’ve seen other ARM boards that make use of pre-existing shields. We would love to see someone remove the processor and implement Arduino-like shields for different processors outside of the LPC214x series. Promo video after the break. Continue reading “Low-cost ARM7 Prototyping” →

Drilling Precise Grids

September 9, 2009 by Mike Szczys 13 Comments

precision_hole_drilling

Drilling precise grids without a CNC machine can be tough to pull off. [Ookseer] has come up with a nifty method for dilling aligned holes with a drill press. He uses a right-angle jig on a Dremel drill press with stacks of business cards as spacers. The same number of cards is added between the substrate and the jig to space each new hole evenly. This method comes in handy when drilling grids in an enclosure for speakers, temperature sensors, or for an aesthetically pleasing design.

Direct-to-PCB Inkjet Printing

September 2, 2009 by Phil Burgess 33 Comments

inkjet-pcb

Full Spectrum Engineering has offered up a tutorial for their inkjet direct PCB kits that repurpose direct-to-CD capable inkjet printers (such as the Epson R280) to print etch-resistant ink straight onto copper clad board. This is easier and less error prone than some iron-on methods, especially for two-sided boards. Just print (no need to reverse the design), dry on a hot plate or in a toaster oven for a couple minutes, and your board’s ready for etching!

Homebrew methods exist for all of this, but for those who would rather move ahead with their design than spend time scrounging for the required bits, the kits offer a pretty good value. They can also meet you halfway…say if you’re only lacking access to a laser cutter and just want the CD stencil…all of the parts are available individually or as a complete set: the resist ink cartridge, the stainless steel board-holding stencil, and a supply of double-sided copper clad boards precisely sized for the stencil (3.5 by 2.5 inches). The small board size is well within the limits of the freeware Eagle Light Edition software.

Concerned about gunking up your nice inkjet with non-OEM ink? You can dedicate hardware to the job without breaking the bank. Many of the compatible printers are of the “free printer after rebate” bundle variety that can now be found inexpensively on Craigslist or eBay.

Hacking DMM Tweezers

August 31, 2009 by Caleb Kraft 8 Comments

_smart_tweezers_Calibration_Pot

These Tweezers are pretty cool tools for anyone doing SMD components. We tried them out and found them very pleasant well made. They are able to identify components and take readings easily with one hand. One thing they are missing, however, is the ability to measure voltage. The people over at Openschemes decided to see if there was a way around that. As it turns out, the chip used in the unit already has the capability to measure voltage. They take us through the process of modding the unit to be able to take advantage of this un utilized feature. From the outside, the only difference is a new switch to set the mode to voltage. Great job guys.

[via Hacked Gadgets]

Push Potentiometer From Spares

August 28, 2009 by Caleb Kraft 8 Comments

In an effort to simplify his interface, [danwagoner] cobbled together this push potentiometer. It utilizes a potentiometer mounted directly above a push button with a spring mounted around it. This way the user has only one item to deal with. They can twist the knob and press down on it to push the button. We love seeing people come up with ways of creating their own items instead of buying something. This was fairly inventive and reminds us of the LED buttons we saw back in January. Great job [danwagoner].