Macetech’s ChronoDot is a Real Time Clock module for projects requiring highly accurate time keeping and measurement. The ChronoDot uses the DS3231 chip, which features a TCXO to compensate for variations in temperature which affect normal oscillators, like the ones in most microcontrollers. The DS3231 uses simple I2C commands and registers for storing and retrieving time, but also features a variable output that goes all the way down to 1.000 hz for low power, interrupt style timekeeping applications. With the provided watch battery, the ChronoDot can keep time in idle mode for up to 8 years.
Normally the ChronoDot comes mostly assembled, requiring you to only solder on the watch battery. However, due to a manufacturing mistake, Macetech is selling a version with the header pins on the wrong side they call the ChronoDoh. This module is currently nearly half off the regular price of $14.99, which makes it a great low cost addition to a project. Macetech has sent us a couple of these modules to demonstrate how functional they still are.
[Blair] feels the unit compares favorably to buying a similarly-priced secondhand analog oscilloscope. The DSO nano wins major points for ease of use, a good range of functionality, and of course the whole portability thing (the enclosure is a repurposed portable media player). Can’t say we’re entirely convinced though. As a single-trace ’scope with 1 MHz bandwidth, the DSO nano may be extremely limiting for anything but basic hobbyist use…which, to be fair, is exactly how they’re marketing it. We can see a place for this the same way there’s a place for $10 multimeters — an inexpensive, toss-in-the-toolbag second ’scope to quickly test for vital signs, something that might complement but not replace a good bench unit.
[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.
A decent drill press is a crucial tool for an electronics lab. We use our drill press to make holes in our own circuit boards, and tap or break traces on existing circuit boards. We’ve used a lot of tools to drill circuit boards — power drills, power drills in “drill press stands”, and high-speed rotary tools — but when we started doing projects on a schedule, it was time for something more reliable.
We first spotted the Proxxon TBM115/TBM220 drill press in the window of a local shop. Its tiny size and adjustable speed seemed ideal for drilling circuit boards. At $200, this is one of the pricier tools in our lab, but quality bearings and smooth drilling action aren’t cheap. Read about our experience with this tool below the break.
The ThingamaKIT is an anthropomorphic analog synthesizer kit from Bleep Labs. Using “LEDacles”, photoresistors, knobs, and switches, it generates interesting high pitched vocalizations. Bleep Labs sent us a review unit and this article shares our experiences building and using the kit. We’ve also included a tutorial on making some hacks, modifications, and circuit bends to it. Skip to the end to see a video of our hacked kit in action.
The WiFi uploading Eye-Fi SD card made a big splash when it was first introduced, but now Eye-Fi has a whole line of different products. The top of the line is the Eye-Fi Explore, which supports geotagging without using a GPS. Instead of GPS hardware, it uses the Skyhook Wireless Wi-Fi Postitioning System, which correlates the position of the Eye-Fi’s access point to GPS locations, creating virtual GPS functionality. This allows photos taken with the Eye-Fi to be be geotagged. Of course, the accuracy of the system is noticeably lower than true GPS and seems to be affected by a number of external factors, but it is still accurate enough to tag the photo within the immediate vicinity of where it was taken.
WiFi positioning is great feature, but certainly not limited to photography. Since the Eye-Fi is at its core SD storage media, you could probably have it geotag data saved to the card, even if it wasn’t created by a digital camera..
Download squad has posted a thorough review of OpenSUSE 11.0. Previous versions of the Linux distro were plagued by thorny and confusing installations, but OpenSUSE 11.0 installs much more easily and cleanly. After a few standard configuration screens, the user has several options for admin accounts, disk partitions, dual-boot setups, and more. The installation of the OS files takes about 20 minutes from there, followed by a quick reboot and first boot, making for a highly customizable yet speedy install from start to finish.
The other major problem with previous versions was the inconsistent speed of their package handling system. In 11.0, though, a new command line app called Zypper makes installing updates, patches, and other packages much faster.
The final verdict is that OpenSUSE 11.0 has become a viable alternative to Ubuntu; the overall quality of the open source distro was never in question, but now that speed has gone from being its biggest deficiency to being one of its biggest strengths, we expect to see a lot more chameleons in the wild.