A gravimeter, as the name suggests, measures gravity. These specialized accelerometers can find underground resources and measure volcanic activity. Unfortunately, traditional instruments are relatively large and expensive (nearly 20 pounds and $100,000). Of course, MEMS accelerometers are old hat, but none of them have been stable enough to be called gravimeters. Until now.
In a recent edition of Nature (pdf), researchers at the University of Glasgow have built a MEMS device that has the stability to work as a gravimeter. To demonstrate this, they used it to measure the tides over six days.
The device functions as a relative gravimeter. Essentially a tiny weight hangs from a tiny spring, and the device measures the pull of gravity on the spring. The design of the Glasgow device has a low resonate frequency (2.3 Hz).
Small and inexpensive devices could monitor volcanoes or fly on drones to find tunnels or buried oil and gas (a job currently done by low altitude aircraft). We’ve covered MEMS accelerometers before, although not at this stability level. We’ve even seen an explanation from the Engineer Guy.
News Globus is an unusual physical interface that piques the curiosity of people and asks them to explore the world by the news putting in relation places of the world. It was designed by Bjorn Karmann, Charlie Gedeon, Mikio Kiura, Sena Partal wiring 20 regions to a Genuino board inside the sphere. When two regions are connected with the jack, the Genuino selects a country randomly from each region and queries the NY Times API for news containing both locations. A web server then selects a story and converts the headline and byline to a mp3 file which is played either from the headphone jack or the speaker at the base of the globe:
The shape of the globe is an interesting artifact from the past which was combined with modern technologies and online services. Instead of allowing people to hear the news of one place, the audio jacks bring to mind the metaphor of the phone operator to get people to discover surprising connections between places near and far from each other.
Seeed Studio shares our vision for the open source community. Since the beginning, Seeed has been our partner for project manufacture, sales, and shipping. That free us to concentrate on the fun stuff, but still make projects available to the community.
Seeed kicked off a spring sale on Mar 1st. Each week they’ll have a Flash Deal, with additional discounts during the whole month. If you are itching to pick up one of our projects, this might be the best chance. Seeed is offering these discounts themselves – you get a deal and we still get paid!
Recycle an ATX computer power supply into a beefy bench tool that powers your projects. The ATX breakout board routes the -12, 3.3, 5 and 12 volt ATX outputs to screw terminals, each protected by a 1.25 amp resettable polyfuse. These four voltages cover many common electronics needs, there’s even a negative voltage (-12 volts) for op amps and audio projects. Get the deal here!
Bus Pirate v4 is a universal bus interface that talks to electronics from a computer serial terminal. Get to know a chip without writing code. Eliminates a ton of early prototyping effort with new or unknown chips. Seeed Studio is the official manufacturer and supporter of the Bus Pirate project. Get the deal here!
256K program space, 4 times more flash than v3
Integrated, on-board USB (faster)
Data storage EEPROM to store settings
Software pull-up voltage selection: 3.3volt, 5volt, or external supply
2 extra I/O pins
To see all our projects at Seeed, please click here.
Last week the “Free PCBs” link in the header began forwarding to a new Free PCB Drawer on the DEV site. Coupon codes from the three weekly giveaways can be used for anything in the Free PCB Drawer category with free shipping. Don’t see something you want? Coupons are also good for $1 off anything else in the store: SLA 3D prints, PCBs, component reels, pogo pins, etc.
Free PCBs are now part of an integrated shipment system and ship daily, instead of “occasionally”. Order status will be updated automatically…once the shipping interface is debugged later this week…
Old coupons are not yet working in the new store. Old coupons will be transferred by the end of next week and we’ll update you here.
So long Zencart, and good riddance! Working with Zencart was awful and it won’t be missed.
On a side note apologies for light updates the past week and a half. We’re struggling a bit to put the final touches on the new site. Tomorrow the first Harmony (pronounced Har-man-y) t-shirt will go up in the store. We also have to make a Hong Kong run to use internet stable enough bring up the Eagle/Gerber/3D print rendering cluster. If the cluster looks solid DirtyPCBs.com will be deprecated in a week, and we’ll only do major support for orders placed at the new site.
Next week a post about getting a Chinese driver’s license. The following week it may finally be time to drop the Expressway, we’ll see how it goes.
We have lost something in PCB design over the last few decades. If you open up a piece of electronics from the 1960s you’ll see why. A PCB from that era is a thing of beauty, an organic mass of curving traces, an expression of the engineer’s art hand-crafted in black crêpe paper tape on transparent acetate. Now by comparison a PCB is a functional drawing of precise angles and parallel lines created in a CAD package, and though those of us who made PCBs in both eras welcome the ease of software design wholeheartedly we have to admit; PCBs just ain’t pretty any more.
It doesn’t have to be that way though. Notable among the rebels are Boldport, whose latest board, a tribute to the late linear IC design legend [Bob Pease], slipped out this month. They use their own PCBmodE design software to create beautiful boards as works of art with the flowing lines you’d expect from a PCB created the old-fashioned way.
The board itself is an update to an earlier Boldport design, and features Pease’s LM331 voltage to frequency converter IC converting light intensity to frequency and flashing an LED. It’s one of the application circuits from the datasheet with a little extra to drive the LED. Best of all the kit is a piece of open-source hardware, so you can find all its resources on GitHub.
We are fans of Boldport’s work here at Hackaday, and it should come as no surprise that we have featured them before. From one of their other kits through several different pieces of PCB wall art, to their work making an appearance in Marie Claire magazine they have graced these pages several times, and we hope this latest board will be one of many more.