A Very, Very Small IMU

The reason we’re playing with quadcopters, flight controllers, motion controlled toys, and hundreds of other doodads is the MEMS revolution. A lot is possible with tiny accelerometers and gyroscopes, and this is looking like the smallest IMU yet. It’s an 18mm diameter IMU, with RF networking, C/C++ libraries, and a 48MHz ARM microcontroller – perfect for the smallest, most capable quadcopter we’ve ever seen.

The build started off as an extension of the IMUduino, an extremely small rectangular board that’s based on the ATMega32u4. While the IMUduino would be great for tracking position and orientation over Bluetooth, it’s still 4cm small. The Femtoduino cuts this down to an 18mm circle, just about the right size to stuff in a model rocket or plane.

Right now, femtoIO is running a very reasonable Kickstarter for the beta editions of these boards with a $500 goal. The boards themselves are a little pricey, but that’s what you get with 9-DOF IMUs and altimeter/temperature sensors.

Hackaday BAMF Meetup Reaches Critical Mass and Overflows Awesome

I love the Hackaday crowd. Despite a long day standing at a booth or crawling the fairgrounds as a spectator, everyone still made it on Saturday night to the 2nd Annual Hackaday BAMF meetup and made it one for the annals of hacker history. Just look at that crowd… I see a couple of Hackaday Prize Judges, a friend I met in Germany (who I actually found out I first met at this same event last year), and many many more great people. I don’t want to spoil the fun so check out the full size over on [Rich Hogben’s] photo log and see how many you can identify.

We started this gathering last year as a come-as-you-are and bring-what-you’re-proud-of after party to Bay Area Maker Fair. We don’t rent out the bar — O’Neil’s Irish Pub in San Mateo — but we had a handshake agreement for drink tickets (thank you to Supplyframe for buying the first round for everyone) with the bartenders. The place feels like the perfect size, and before long we were packed into every available space. The ramp to the restroom area in the back was a gauntlet of conversation — enough room to walk by but you felt like you were interrupting people talking to those across from them.

The amount of hardware on hand was spectacular. Taking pictures of it was tough in the tight quarters. I got a look at the first prototype of the Pebble smart strap. I really enjoyed seeing OSHChip (pictured above) which is an ARM Cortex-M0 chip and BLE rolled into a DIP-16 form factor. [Sophi’s] HeartBeat Boombox was a big hit; it uses the heartrate and blood oxygen sensors seen above to drive a drumbeat. Those blinky glasses should look familiar. [Garrett Mace] and his colleague [Jason] were on hand. These Macetech glasses are from a couple of years back but don’t worry, they were sporting the newest RGB flavor which I’m told will have black solder mask and integrated controller among other tasty goodies.

Perhaps the best way to tell the success of the night is that there were a lot of friends in the room that I never realized were even there. The next day I met up with [Sarah Petkus] and [Mark Koch] and was surprised to find they had been at the Hackaday meetup and I missed them. The same thing happened when I looked at [Rich’s] album from the night and saw [Trey German] was there too. I wasn’t hiding and I wasn’t stuck in one conversation, it was just that kind of a party that makes the room feel like a TARDIS but somehow the night doesn’t last forever.

It’s hard to imagine BAMF without this Saturday gathering. If you missed it this year, add it to your calendar for next.

Tearing Down The Apple Watch

The Apple Watch has been out for nearly a month now, but so far we haven’t seen a good look at the guts of this little metal bauble of electronic jewelry. Lucky for us that a company in China is hard at work poking around inside the Apple Watch and putting up a few incredible SEM images along the way (Google Translatrix).

This isn’t the first Apple Watch teardown that’s hit the intertubes – iFixit tore one apart with spudgers and tiny screwdrivers and found someone skilled in the ways of tiny parts could probably replace the battery in this watch. Shocking for an Apple product, really. iFixit also took a look at the watch with an x-ray, revealing a little bit of the high-level design of the Apple Watch, the Apple S1 computer on a chip, and how all the sensors inside this wearable work.

A side view of a 6-DOF IMU
A side view of a 6-DOF IMU

This teardown uses an incredible amount of very high-tech equipment to peer inside the Apple Watch. Because of this, it’s probably one of the best examples of showing how these tiny sensors actually work. With some very cool images, a 6-DOF IMU is revealed and the Knowles MEMS microphone is shown to be a relatively simple, if very small part.

Now the Apple S1, the tiny 26.15mm x 28.50mm computer on a chip, serves as the brains of the Apple Watch. It’s breathtakingly thin, only 1.16mm, but still handles all the processing in the device.

Even if you won’t be buying this electronic accessory, you’ve got to respect the amazing amount of engineering that went into this tiny metal bauble of semiconductors and sensors.

Colorizer for ZX81 clone

[danjovic] is a vintage computer enthusiast and has several old computers in his collection. Among them are a couple of TK-85 units – a ZX81 clone manufactured by Microdigital Eletronica in Brazil. The TK-85 outputs a monochrome video output. And when [danjovic] acquired a SyncMaster 510 computer monitor, he went about building a circuit to “colorise” the output from the ZX81 clone (Portuguese translation).

The SyncMaster 510 supports 15kHz RGB video refresh rate, so he thought it ought to be easy to hook it up to the TK-85, which internally has the video and composite sync signals available. So, if he could lower the amplitude of the video signal to 0.7Vpp, using resistors, and connect this signal to one of the primary colors on the monitor, for example green, then the screen should have black characters with a green background.

DSCN5584-thumbBefore he could do any of this, he first had to debug and fix the TK-85 which seemed to be having several age related issues. After swapping out several deteriorating IC sockets, he was able to get it running. He soldered wires directly to one of the logic chips that had the video and sync signals present on them, along with the +5V and GND connections and hooked them up to a breadboard. He then tested his circuit consisting of the TTL multiplexer, DIP switches and resistors. This worked, but not as expected, and after some digging around, he deduced that it was due to the lack of the back porch in the video signal. From Wikipedia, “The back porch is the portion of each scan line between the end (rising edge) of the horizontal sync pulse and the start of active video. It is used to restore the black level (300 mV.) reference in analog video. In signal processing terms, it compensates for the fall time and settling time following the sync pulse.”

To implement the back porch, he referred to an older hack he had come across that involved solving a similar problem in the ZX81. Eventually, it was easily implemented by an RC filter and a diode. With this done, he was now able to select any RGB value for foreground and background colors. Finally, he built a little PCB to house the multiplexer, DIP switches and level shifting resistors. For those interested, he’s also documented his restoration of the TK-85 over a four-part blog post.

FUBAR Labs Gets A New Space

FUBAR Labs in New Jersey is one of the finest and most productive hackerspaces in the US. They have homebrew rocket engines, the eternal gratitude of semiconductor companies, and a broken Makerbot nailed to the wall: everything a hackerspace should have. Now they’re moving to a new space, and they’re looking for a little funding to turn their lab into what it should be.

There have been a lot of cool builds that have come out of FUBAR Labs including a Power Wheels racer, [Rick]’s Minecraft Circuits In Real Life, the now-obviously named Fubarino, a 3D printed balance bot. a gaseous oxygen and ethanol rocket engine.

Their 890 square foot space was already fantastic, but with a new space that’s 2300 square feet, they’ll be able to expand New Jersey’s finest hackerspace into what it should already be.

The guys at FUBAR put up a gallery of pics of the new space. You can check those out here. Next time Hackaday is in Jersey – or when we forget how to pump our own gas, whatever comes first – we’ll do a hackerspace tour of the new space.

Hackaday Prize Entry: A BeagleBone Logic Analyzer

If you have a BeagleBone, you already have a lot of tools. We’ve seen them used in driving hundreds of LEDs at a very high frame rate, used as a video card for ancient computers, and as a software defined radio. For his entry to The Hackaday Prize, [Kumar] turned his BeagleBone into a 14-channel, 100Msps logic analyzer that’s good enough to debug just about all those hobby electronics projects you’re working on.

The BeagleBone is only able to have this sort of performance as a logic analyzer because of its PRUs, those fancy peripherals that make the Beagle great at blinking pins really, really fast. [Kumar] is using both PRUs in the BeagleBone for this project. PRU1 reads from the input probes, and PRU0 writes all the samples into DDR memory directly. From there, the samples are off to kernel modules and apps, either sigrok, dd, or something you coded up in Python.

Compared to the cheap logic analyzers we have today like the Salae Logic and the DSLogic, [Kumar]’s project is just as good as any commercial offering (provided you can live with 14 channels instead of 16), and because it’s based on a BeagleBone, the software is infinitely expandable.

UPDATE: After this post was written but before it was published, [Kumar] finished up a blog post on how he’s building a logic analyzer with the BeagleBone’s PRUs. It’s a true tutorial, with enough code demos to allow anyone to build their own 8-bit analyzer on a BeagleBone, and there are more updates coming.


The 2015 Hackaday Prize is sponsored by:

“Bricking” Microcontrollers in LEGO Motivates Young Programmers

Back when he was about seven years old, [Ytai] learned to program on an Atari 800XL. Now he has a seven-year-old of his own and wants to spark his interest in programming, so he created these programmable LEGO bricks with tiny embedded microcontrollers. This is probably one of the few times that “bricking” a microcontroller is a good thing!

IMG_20150519_144818The core of the project is the Espruino Pico microcontroller which has the interesting feature of running a Java stack in a very tiny package. The Blocky IDE is very simple as well, and doesn’t bog users down in syntax (which can be discouraging to new programmers, especially when they’re not even a decade old). The bricks that [Ytai] made include a servo motor with bricks on the body and the arm, some LEDs integrated into Technic bricks, and a few pushbutton bricks.

We always like seeing projects that are geared at getting kids interested in creating, programming, and hacking, and this certainly does that! [Ytai] has plans for a few more LEGO-based projects to help keep his kid interested in programming as well, and we look forward to seeing those! If you’re looking for other ways to spark the curiosity of the youths, be sure to check out the Microbot, or if you know some teens that need some direction, perhaps these battlebots are more your style.