Reader [Mikey Sklar] told us about a review he wrote covering 3 different models of pocket multimeters. We’re sure that you’ve had the same experiences we have being the go-to-guy or got-to-gal  for all things electrical. For our sort, having a multimeter on hand at all times has become an expectation.

[Mikey] looks at a model from ebay, Harbor Freight, and Radio Shack. Not surprisingly, the ebay offering doesn’t rate too well but does get the job done. We were surprised to read that he picked up the Cen-Tech model for about $10 at Harbor Freight. Although it may no longer be sold there (we haven’t checked) [Mikey] seems pretty happy with it so we’ll be on the lookout during our next tool-buying trip. We’re unfamiliar with the tiny Radio Shack 22-820 but we’ve always been happy with our larger 22-811. The 22-820 allows the probes to be folded up inside of the case cover for a truly pocketable package.

You can never have too many meters at your disposal and we’ll have to keep this article in mind the next time we’re shopping for another. Never used a multimeter before? Take a look at the tutorial [Mikey] linked to over at ladyada.

Here’s another adafruit product launched today: a prototyping shield that compensates for the Arduino’s stupid oddly spaced headers.

Related: The Seeeduino has an alternate row of headers with protoboard friendly spacing.

adafruit industries’ latest product is an adjustable breadboard power supply kit. We’ve seen breadboard supplies before, but like most of adafruit’s kits, this is the best design you’re going to encounter. It uses an MIC2941 voltage regulator instead of the more commonplace LM317. It has a very low dropout which means your output voltage can be much closer to the input voltage. Their example is using 3AAA or a Li-Ion battery for an output of 3.3V. Input can be through a barrel jack or terminal blocks. There is a selection switch for 3.3, 5, and adjustable voltage. Using the adjustment pot you can select an output voltage anywhere from 1.3V to within .5V of the 20V maximum input. The adjusted output voltage will remain the same even if you increase the input voltage. Like all of their kits, you can find schematics, assembly and usage instructions, on their project site.

Our friends over [adafruit] recently released the Sensor Pack 900, a collection of parts for anyone who is interested in using analog sensors with their projects. The pack includes 9 sensors. They range from simple thermistors and hall effect sensors to sharp distance sensors. Also included in the pack are 3 unidentified components that can be used to interface with the analog sensors in the pack. At only $30, the Sensor Pack 900 seems to offer a great set of introductory components for anyone prototyping a new device.

[adafruit] wrote in to let us know that the Tweet-a-Watt is now available in kit form. While the plans have been available for a while, a kit is a welcomed addition. The kit doesn’t include the Kill-a-Watt monitor, but rather the XBee adapters and parts necessary to make it talk to your Arduino or computer. The kit is $90, while the Kill-a-Watt can be found for roughly $20.

After seeing the xkcd comic where they call the Kindle2 the hitchhiker’s guide, [Ladyada] couldn’t help but laser etch the Kindle 2 with “Don’t Panic”. We think it looks pretty good, if a bit bubbly. You can see the video of the entire process after the break. Now that xkcd has infiltrated our interwebs, hearts, and minds, maybe he can put just a tiny bit of effort into learning to draw. If you don’t have access to a laser etcher, you could always make your own. Just be careful you don’t accidentally go full out and cut your kindle to shreds.

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[ladyada] has republished an interesting snippet from the synthDIY mailing list. [David Dixon] discusses the actual chemistry behind ferric chloride based home circuit board etching. He concludes that ferric chloride is essentially a ‘one-shot’ oxidant. It can’t be regenerated and can be difficult to dispose of properly. The use of acidified copper chloride is a much better path and becomes more effective with each use, as long as you keep it aerated and top up the acidity from time to time. This etchant solution is actually the result of initially using hydrogen peroxide as an oxidant along with muriatic acid. You can see us using this solution in our etching how-to and while creating the board for our RGB lock. For more information on using hydrogen peroxide, check out [Adam Seychell]’s guide and this Instructable.

Aside: [ladyada] has added the receiver code to the Wattcher project page.

You probably saw [Phillip Torrone] and [Limor Fried]’s twittering Kill A Watt earlier this week. It was an entry in the Core77/Greener Gadgets Design Competition. We saw a little bit about how it was assembled, but now they’ve posted a full guide to assembling the hardware. Each Kill A Watt gets an XBee radio that transmits back to a receiver that logs the power usage. The difficult part when putting this design together was the XBee required 50mA when transmitting. This is well above the Kill A Watt’s internal power supply. They remedied this by adding a 10,000uF supercap to act as a rechargeable battery. The daily twittering is just a side-effect of the project. The Kill A Watts transmit every 2 seconds, so you’ll get a very accurate report of your power usage. This is a great project for renters who can’t permanently modify their power infrastructure. Each Kill A Watt can support quite a few appliances since they’re rated for 15A, ~1800W.

The team at oomlout has continued to post all the methods they use in their manufacturing process. This time around it’s the kitting process: how they actually packaged 30 identical SERB kits in an efficient fashion. We covered their wire cutting bot before, but they’ve got other dedicated machines like a sticker cutter. The stickers are used to remove all the cut acrylic pieces from the laser cutter as one unit. They’ve got some other tricks like using a scale to count bolt quantities, and an egg timer to keep track of the laser cutting. All of their envelopes are printed using a parallel port inkjet that has been modified to work with any thickness paper.

We love when hackers bother to post this much detail about their process. One of our favorites is [ladyada]’s full rundown of how the Minty Boost was created.

[Rory Hyde] and [Scott Mitchell] are exploring several projects that add more information to public spaces. The first is the Spoke-o-dometer a persistence of vision device that can display bicycle speed and distance traveled. To develop the device, they first bought a few POV kits to test out. They decided to build their version using an Arduino. Once they had the display proof of concept working, they added a hall effect sensor like the SpokePOV so they could determine speed and orient the display. Check out their project site for plenty of example code and development details.

[via ladyada]