Maker Faire NY: Developing For The Final Frontier

September 28, 2018 by 6 Comments

The cost of getting a piece of hardware into space is now cheaper than ever, thanks in no small part to the rapid progress that’s been made by commercial launch providers such as SpaceX. In the near future, as more low-cost providers come online, it should get even cheaper. Within a few years, we could be seeing per kilogram costs to low Earth orbit that are 1/10th what they were on the Space Shuttle. To be sure, this is a very exciting time to be in the business of designing and building spacecraft.

But no matter how cheap launches to orbit get, it’ll never be cheaper than simply emailing some source code up to the International Space Station (ISS). With that in mind, there are several programs which offer students the closest thing to booking passage on a Falcon 9: the chance to develop software that can be run aboard the Station. At the 2018 World Maker Faire in New York we got a chance to get up close and personal with functional replicas of the hardware that’s already on orbit, known in space parlance as “ground units”.

On display was a replica of one of the SPHERES free-flying satellites that have been on the ISS since 2006. They are roughly the size of a soccer ball and utilize CO2 thrusters and ultrasonic sensors to move around inside of the Station. Designed by MIT as a way to study spaceflight techniques such as docking and navigation without the expense and risk of using a full scale vehicle, the SPHERES satellites are perhaps the only operational spacecraft to have never been exposed to space itself.

Expansion port for additional hardware.

MIT now runs the annual “Zero Robotics” competition, which tasks middle and high school students with solving a specific challenge using the SPHERES satellites. Competitors run their programs on simulators until the finals, which are conducted using the real hardware on the ISS and live-streamed to schools.

We also saw hardware from “Quest for Space”, which is a company offering curricula for elementary through high school students which include not only the ground units, but training and technical support when and if the school decides to send the code to the matching hardware on the Station. For an additional fee, they will even work with the school to design, launch, and recover a custom hardware experiment.

Their standard hardware is based on off-the-shelf platforms such as Arduino and LEGO Mindstorms EV3, which makes for an easy transition for school’s existing STEM programs. The current hardware in orbit is setup for experiments dealing with heat absorption, humidity, and convection, but “Quest for Space” notes they change out the hardware every two years to provide different experiment opportunities.

Projects such as these, along with previous efforts such as the ArduSat, offer a unique way for the masses to connect with space in ways which would have been unthinkable before the turn of the 21st century. It’s still up for debate if anyone reading Hackaday in 2018 will personally get a chance to slip Earth’s surly bonds, but at least you can rest easy knowing your software bugs can hitch a ride off the planet.

Inductance In PCB Layout: The Good, The Bad, And The Fugly

September 28, 2018 by 39 Comments

When current flows through a conductor it becomes an inductor, when there is an inductor there is an electromagnetic field (EM). This can cause a variety of issues during PCB layout if you don’t plan properly, and sometimes we get burned even when we think we have planned for unwanted inductance and the effects that come with them.

When doing high speed logic we need to be able to deliver sudden changes in current to the devices if we want to have proper switching times and logic levels. Unfortunately inductance is usually not a friend in these circumstances as it resists those sudden changes in current. If the high speed devices are driving capacitive loads, which themselves are resisting changes in voltage, even more instantaneous current is needed.

Simply put, inductors resist a change of current, and can act as a low pass filter when in series with the signal or power supply flow. Inductors do this by storing energy in the flux surrounding the conductor. Alternatively capacitors resist a change in voltage (again by storing energy) and can act as a high pass filter when in series with the signal. This makes them a valuable tool in the fight against unwanted inductance in power supply distribution.

In the video below, and the remainder of this article, I’m going to dive into the concept of inductance and how it affects our design choices when laying out circuit boards.

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FPGA Jacked Into Pinball Machine Masters High Scores

September 28, 2018 by 13 Comments

How do you preserve high scores in an old arcade cabinet when disconnecting the power? Is it possible to inject new high scores into a pinball machine? It was the b-plot of an episode of Seinfield, so it has to be worth doing, leading [matthew venn] down the rabbit hole of FPGAs and memory maps to create new high scores in a pinball machine.

The machine in question for this experiment is Doctor Who from Williams, which, despite being a Doctor Who pinball machine isn’t that great of a machine. Still, daleks. This machine is powered by a Motorola 68B09E running at 2MHz, with 8kB of RAM at address 0x0000. This RAM backed up with a few AA batteries, and luckily is in a DIP socket, allowing [matthew] to fab a board loaded up with an FPGA development board that goes between the CPU and RAM.

The basic technique for intercepting and writing a new high score for this pinball machine comes from the incredible [sprite_tm] who is tweeting high scores from a 1943 cabinet. The idea is simple: just have an FPGA look at one specific memory address, and send some data to a computer when the data at that address is updated. For the Doctor Who pinball machine, this is slightly harder than it sounds: the data isn’t stored in hex, but packed BCD. After a little bit of work, though, [matthew] was able to write new high scores from a Python script running on a laptop. All the code (and a few more details) are over on a Github

Extending arcade games by tapping into address and data lines isn’t something we see a lot of, but it has been done, most famously with the Church of Robotron. Here, a few MAME hacks turn a game of Robotron into a Church for the faithful to fully commit themselves to the savior of the world, due to arrive in 66 years and save the remaining humans from the robot apocalypse. This hack of a Doctor Who pinball machine goes beyond a modded version of MAME, and if we’re ever going to make a real chapel with a real game of Robotron, these are the techniques we’re going to use.

Sounding A Sour Note Can Save People From A Sour Stomach (Or Worse)

September 28, 2018 by 13 Comments

We’ve covered construction of novel music instruments on these pages, and we’ve covered many people tearing down scientific instruments. But today we’ve got something that managed to cross over from one world of “instrument” into another: a music instrument modified to measure a liquid’s density by listening to changes in its pitch.

This exploration started with a mbira, a mechanically simple music instrument. Its row of rigid metal tines was replaced with a single small diameter hollow metal tube. Filling the tube with different liquids would result in different sounds. Those sounds are captured by a cell phone and processed by an algorithm to calculate the difference in relative density of those liquids. Once the procedure was worked out, the concept was verified to work on a super simple instrument built out of everyday parts: a tube mounted on a piece of wood.

At this point we have something that would be a great science class demonstration, but the authors went a step further and described how this cheap sensor can be used to solve an actual problem: detecting counterfeit pharmaceuticals. Changing composition of a drug would also change its density, so a cheap way to compare densities between a questionable sample against a known good reference could be a valuable tool in parts of the world where chemistry labs are scarce.

For future development, this team invites the world to join them applying the same basic idea in other ways, making precise measurements for almost no cost. “Any physical, chemical, or biological phenomena that reproducibly alters the pitch-determining properties of a musical instrument could in principle be measured by the instrument.” We are the ideal demographic to devise new variations on this theme. Let us know what you come up with!

If you need to do quick tests before writing analysis software, audio frequency can be measured using the Google Science Journal app. We’ve seen several hacks turning a cell phone’s camera into instruments like a spectrometer or microscope, but hacks using a phone’s microphone is less common and ripe for exploration. And anyone who manages to make cool measurements while simultaneously making cool music will instantly become a serious contender in our Hackaday Prize music instrument challenge!

[via Science News]

Antennas That You Install With A Spray-Can

September 27, 2018 by 30 Comments

With the explosion in cell phones, WiFi, Bluetooth, and other radio technologies, the demand for antennas is increasing. Everything is getting smaller and even wearable, so traditional antennas are less practical than ever. You’ve probably seen PCB antennas on things like ESP8266s, but Drexel University researchers are now studying using titanium carbide — known as MXene — to build thin, light, and even transparent antennas that outperform copper antennas. Bucking the trend for 3D printing, these antennas are sprayed like ink or paint onto a surface.

A traditional antenna that uses metal carries most of the current at the skin (something we’ve discussed before). For example, at WiFi frequencies, a copper antenna’s skin depth is about 1.33 micrometers. That means that antennas have to be at least thick enough to carry current at that depth from all surfaces –practically 5 micrometers is about the thinnest you can reasonably go. That doesn’t sound like a lot, but when you are trying to make something thin and flexible, it is pretty thick. Using MXene, the researchers made antennas as thin as 100 nanometers thick — that’s 10% of a micrometer and only 2% of a conventional antenna.

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Three Part Deep Dive Explains Lattice ICE40 FPGA Details

September 27, 2018 by 15 Comments

It is no secret that we like the Lattice iCE40 FPGA. It has a cheap development board and an open source toolchain, so it is an easy way to get started developing low-cost, low-power FPGA designs. There are a few members of the family that have similar characteristics including the top-of-the-line UltraPlus. [Steve] from Lattice and [Michael Klopfer] from the University of California Irvine have a three-part video series that explain the architecture of the devices. Altogether, the videos are about an hour long and — of course — they use the official tools, not IceStorm. But it is still a great time investment if you have an iCE40 board and you want to understand what the chip has under the hood.

The first part is fairly short and talks a lot about applications. There’s also a nod to the hobbyist use of FPGAs. Keep in mind that the iCE40 FPGAs come in different sizes and variants, so don’t get excited when you see them mention a RISC-V — that isn’t going to fit in your iCEStick, that we know of. The iCEstick has a HX-1K onboard, which is the high-performance variant with 1,280 logic elements, as opposed to the low-power (LP) version.

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LEGO bricks sorter

Sorting LEGO Is Like Making A Box Of Chocolates

September 27, 2018 by 6 Comments

Did you know that chocolate candy production and sorting LEGO bricks have something in common? They both use the same techniques for turning clumps of chocolates or bricks into individual ones moving down a conveyor belt. At least that’s what [Paco Garcia] found out when making his LEGO Sorter.

Sorting LEGO bricks using guidesHowever, he didn’t find that out right away. He first experimented with his own techniques, learning that if he fed bricks to his conveyor belt by dropping a batch of them in a line perpendicular to the direction of belt travel then no subsequent separation attempt of his worked. He then turned to [akiyuky’s] LEGO sorter for inspiration and dropped them onto the belt at an angle, ensuring that some bricks would be in front of others. A further trick he found is very well demonstrated in the chocolate sorting video below and shown in the image here. That is to use guides on the belt which serve to create speed differentials. Bricks move slower than the conveyor belt while pressed against a guide but when a brick leaves the guide, it accelerates to the speed of the conveyor belt, pulling away from the bricks still at the guide and thus separating them.

A further discovery had nothing to do with chocolate production, unless maybe for quality control. Once an individual brick had been separated out, it had to be classified. To do that he used Google’s Inception v3 neural network. But first, he had to retrain it for recognizing different types of LEGO bricks, something we’ve seen done before for use with recognizing playing cards. And to do the retraining, he needed many images of different bricks all separated into their different types. That’s where he came up with a clever trick. He used his own sorter for that. For example, to get a bunch of images of 1×1 bricks of different colors and orientations, he simply ran them through the sorter, saving the images to files and assigning them to the 1×1 brick class. He then used his desktop machine with a GeForce GT 730 GPU for the retraining, taking around 2.7 seconds per brick. For sorting though, he runs the trained neural network on a Raspberry Pi, taking 3.8 seconds for each brick. The resulting sorter works quite well, sorting with 89% accuracy. Watch it in action in the video below.
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